TY - JOUR A1 - Plarre, Rüdiger A1 - Trepkau, B. T1 - Von der Aufgabe, die Natur zu normen – DIN-Normenausschuss Holzwirtschaft und Möbel (NHM) - Normungsarbeit im Fachbereich Holzschutz N2 - Normativ ist der Holzschutz in Deutschland durch die DIN 68800-Reihe geregelt. Die Normungsarbeit in CEN/TC 38 bildet dafür den Rahmen, der national angepasst und fachspezifisch erweitert wurde. Zusammen mit dem Kommentar ergeben beide ein in Europa einzigartiges Regelkompendium im Holzschutz. In Zukunft wird die Regelsetzung noch stärker durch internationale Zusammenarbeit bestimmt sein. Der interkontinentalen Marktöffnung sollten Verständigungen auf gemeinsame Qualitätsstandards vorausgehen. KW - Holzschutz KW - Normung KW - DIN KW - CEN KW - ISO PY - 2018 SN - 0722-2912 SN - 0011-4952 VL - 2018 IS - 12 SP - 22 EP - 30 PB - Beuth AN - OPUS4-47104 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Plarre, Rüdiger A1 - Cabral, U. A1 - Querner, P. ED - Ryder, S. ED - Crossman, A. T1 - Screening of two plant-derived extracts from Sri Lanka for their potential to control the subterranean termite Coptotermes formosanus N2 - The tropical environment of Sri Lanka accelerates bio-deterioration of cultural objects. Termites are one of the most damaging insect pests destroying the cellulose components of historical artifacts. Herbal extracts obtained from resin of Vateria copallifera (Retzius) Alston and seeds of Madhuca longifolia (Konig) Macbride have been used for centuries to preserve e.g. palm leaf manuscripts from insect attack. Herbal extractions of these traditional products for palm leaf manuscript were tested for their effect against the termite species Coptotermes formosanus Shiraki, 1909. Natural and artificial aged herbal extractions were tested to obtain a repellent index. Resin oil of V. copallifera caused slightly higher repellencies than M. longifolia. Artificially aged samples produced lower repellencies than naturally aged samples. The results indicate that the active ingredients are volatile. The potential for barrier treatment was tested only with V. copallifera. Tunnelling-behavior of C. formosanus workers through sand in the presence of V. copallifera resin oil was largely reduced. T2 - Pest Odyssey The Next Generation CY - Online meeting DA - 20.09.2021 KW - IPM in museums KW - Termite control KW - Essential oils KW - Library pests PY - 2022 SN - 978-1-909492-83-7 SP - 56 EP - 62 PB - Archetyp Publication LTD CY - London AN - OPUS4-54736 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Plarre, Rüdiger A1 - Busweiler, Sabine A1 - Haustein, V A1 - von Laar, C. A1 - Haustein, T ED - Bueno-Mari, R ED - Montalvo, T ED - Robinson, W H T1 - Korynetes caeruleus (coleoptera: cleridae) for biological control of anobium punctatum (coleoptera, ptinidae) N2 - Larvae and adults of Korynetes caeruleus (de Geer 1775) (Coleoptera: Cleridae) were collected from old churches and reared in the laboratory on Anobium punctatum (de Geer 1774) (Coleoptera, Ptinidea, formerly Anobiidae). Breeding success of K. caeruleus was low, but basic parameters of this species’ developmental cycle were identified. At 21 °C and 75 % relative humidity and a four-month cold period at 4 °C, the development of K. caeruleus from egg to adult appearance lasted 2 years. The pupal stage may be reached and completed after one and a half years. Feeding on larvae of A. punctatum by larvae of K. caeruleus was observed and consisted of a combination of sucking haemolymph and consuming body parts. The sickle-like mandibles of larvae of K. caeruleus penetrate the cuticle of prey larvae followed by pumping and sucking body movements. Adult beetles of A. punctatum were not attacked by K. caeruleus larvae. Feeding behavior of adult K. caeruleus was not investigated. T2 - 10th International Conference on Urban Pests CY - Barcelona, Spain DA - 26.06.2022 KW - Cultural heritage KW - Biological pest control KW - Life history data KW - Wood protection PY - 2022 SN - 978-84-09-41424-6 SP - 34 EP - 44 AN - OPUS4-55170 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Plarre, Rüdiger A1 - Busweiler, Sabine T1 - Erneute Antennen-Anomalie beim Hausbockkäfer Hylotrupes bajulus (Coleoptera: Cerambycidae) in der F3-Generation N2 - Second occurrence of aberrant antenna in house longhorn beetle Hylotrupes bajulus (Coleoptera: Cerambycidae) in the F3 generation. In 2016, the house longhorn beetle (Hylotrupes bajulus) breeding culture of the Federal Institute for Materials Research and Testing (BAM) in Berlin produced a second female beetle with a unique malformed right antenna similar to the one previously reported. As in the first case the flagellum following the pedical was bifurcated. This time, however, both branches were of similar length with 7 and 8 flagellomeres, respectively. The left antenna was normally developed with 11 antennal segments (scape, pedicel and 9 flagellomeres). This second female stands as F3-generation in direct maternal line to the previous one. A heritable cause for the malformation is likely. KW - Hausbockkäfer KW - Entwicklung KW - Vererbung PY - 2018 SN - 0037-5942 VL - Neue Folge 53 SP - 101 EP - 105 PB - Gesellschaft Naturforschender Freunde zu Berlin CY - Berlin AN - OPUS4-44052 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Plarre, Rüdiger T1 - Ungebetene Gäste im Museum – Biologie von Kleidermotte, Holzwurm und Co. N2 - Gemeiner Nagekäfer und Kleidermotte sind unerwünscht im Museum. Kulturgüter mit Anteilen von Holz, Federn, Wolle, Haare, etc. wie ethnologische oder naturkundliche Sammlungsstücke, aber auch Bilderahmen oder Freilichtmuseen werden von ihnen gerne besucht. Dabei sind es die Jugendstadien (Larven) dieser Insekten, die sich von ungeschützten Exponaten oder Depotstücken, die diese natürlichen Materialien enthalten, ernähren. Die Entwicklung der Larven findet verborgen im Inneren der Materialien statt. Die geflügelten erwachsenen Formen, die sich im freien Raum bewegen, sich fortpflanzen und den Neubefall herbeiführen, treten saisonal sehr begrenzt auf. Eine frühzeitige Detektion der Schädlinge, als erwachsenes Insekt oder als Larve, ist dadurch erschwert. Es gilt folglich deren Präsenz und erste Anzeichen eines Befalls zuverlässig und vor allem frühzeitig feststellen zu können, um geeignete Maßnahmen zum Schutz des Kulturgutes einzuleiten. Neben dem Wissen um die Materialeigenschaften des Kulturgutes sind umfängliche Kenntnis über die Biologie der Schädlinge, zu ihren grundsätzlichen Lebensansprüchen und insbesondere zum Verhalten, das zum Neubefall führt, wichtig. Die Larvenstadien von Holz- und Textilschädlingen zeichnen sich durch hohe Toleranzen gegenüber extremen Temperaturen und Luftfeuchten aus. Für sie ungünstige Bedingungen können sie sehr lange in Ruhephasen überdauern. Nicht erkannter, versteckter Befall von Materialien sind häufige Infektionsquellen für Neubefall von Sammlungen. Verborgene natürliche Befallsquellen im eigenen Museumssystem spielen bei Neubefall von Exponaten eine größere Rolle als der Zuflug von Schadinsekten aus Reservoiren von außen. Der Vortrag stellt beispielhaft Lebenszyklen relevanter Schädlingsarten vor und zeigt Möglichkeiten gezielter Interventionen auf, die in ein IPM Konzept einfließen können. Dies umfasst vorbeugende Maßnahmen wie geeignetes Klima in Ausstellungs- und Lagerräumen, das sogenannte Monitorring sowie eine konsequente Quarantäne bis hin zu physikalischen, biologischen oder chemischen Bekämpfungsmaßnahmen. T2 - AK Konservierung/Restaurierung Doerner Institut CY - Munich, Germany DA - 06.12.2018 KW - IPM KW - Kulturgut KW - Hausbock KW - Kleidermotte PY - 2018 AN - OPUS4-46962 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Plarre, Rüdiger T1 - Uninvited and Welcomed Guests in Museums – Biological management of clothes moths and woodworms N2 - In museums and historic houses clothes, moths (Tineola bisselliella, Tinea pellionella) and the furniture beetle (Anobium punctatum) are the most economically important pests on textiles or wooden artifacts, respectively. Their management is essential to protect cultural ethnological heritage and natural history collections for future generations. Pest management strategies have changed over time. Today, intensive knowledge on pest biology and overall material science are key cornerstones in IPM concepts - also for the museum environment. The important first steps for sustainable pest management are risk assessment, early pest detection and identification of pathways of infestation. These steps are followed by physical and biological means of control, which have lately gained more importance than applying biocides. Several potentially effective biological enemies of clothes moths and woodworm have been known for a long time, but their promotion for pest control in museums and historic houses is just beginning. This short review summarizes current concepts of pest life cycle interruption by applying good quarantine and very specific biological measures. The lessons learned from recent faunistic surveys, life-history studies as well as behavioral observations of parasitoids and predators of clothes moths and woodworm may supplement the pest management tool box. The need for further research in this field is addressed. T2 - IOBC-WPRS CY - Pisa, Italy DA - 03.09.2019 KW - Biological Control KW - Museum Pests KW - Tineola bisselliella KW - Anobium punctatum KW - Apanteles carpatus KW - Baryscapus tineivorus KW - Corynetes caeruleus PY - 2019 AN - OPUS4-48901 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Plarre, Rüdiger T1 - Eine kleine kleine Natur- und Kulturgeschichte der Kleidermotte (Tineola bisselliella) N2 - A short natural and cultural history of the webbing clothes moth (Tineola bisselliella). It is generally accepted that the natural habitats of most pest insects can be found outside the synanthropic environment in layers of leaf litter, under bark, as well as in rodent or bird nests. Indeed, most of the common fabric pests have been reported as being facultative nidicolous. Therefore, infestation of commodities by pest insects out of these reservoirs is one possibility to be considered. However, the likelihood of a pest´s occurrence and survival outside of the synanthropic habitat largely depends on its ecological potential and competitiveness against other species of the same ecological guild. Some pest species are rarely found in wild habitats, especially in those regions where they are not native and where they have been introduced by man. The fabric pest Tineola bisselliella serves as a good example. Most likely originating from Central or Southern Africa, this insect was introduced into Europe probably not earlier than the late 18th century. Being more tolerant to dry environments than other fabric pests, its economical importance increased during the 20th century when the indoor climate changed because of central heating systems. Its occurrence in outdoor natural habitats must be regarded as accidental. Reported finds of webbing clothes moth larvae in bird nests e. g. have been largely overstated in the literature. Tineola bisselliella should be regarded as an invasive and eusynanthropic species in most parts of the world. KW - Textilschädling KW - Museumsschädling KW - Anpassung KW - Evolution PY - 2018 SN - 0037-5942 VL - Neue Folge 53 SP - 43 EP - 57 PB - Gesellschaft Naturforschender Freunde zu Berlin CY - Berlin AN - OPUS4-44048 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Plarre, Rüdiger T1 - Resultiert normgerechte Ausführung verlässlich in hoher Qualität? N2 - Normgerechte Ausführung resultiert in Qualität, aber sie ist nicht allein ein Garant auch für hohe Qualität. Hierfür sind begleitend immer auch nachgeordnete Richtlinien wie z. B. spezifische Gütekriterien zu erfüllen. Der Vortrag erklärt die Normungsarbeit auf nationaler und internationaler Ebene und schildert die Stärken aber auch die Schwächen bei der Erstellung von Normen. Dabei ist die Konsensbildung zwischen unterschiedlichen interessierten Kreisen mit deren Partikularinteressen oftmals ein Hindernis, das aber über Zusatzvereinbarungen und der Norm nachgeordneten Regeln überwunden werden kann. T2 - Tagung des Deutschen Holzschutzfachverbandes für Ausenholzprodukte CY - Berlin, Germany DA - 19.01.2018 KW - Normung KW - DIN KW - CEN KW - ISO KW - Gütezeichen PY - 2018 AN - OPUS4-43852 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Plarre, Rüdiger T1 - Eine kleine Natur- und Kulturgeschichte der Kleidermotte – nebst Möglichkeiten ihrer biologischen Bekämpfung N2 - Zu den unerwünschten Gästen im Museum oder im Haushalt gehört zweifelsohne die Kleidermotte Tineola bisselliella. Es sind die Larven dieses Kleinschmetterlings, die die Schäden verursachen. Neben der konventionellen Schadensabwehr besteht die Möglichkeit, Schlupfwespen zur Bekämpfung der Larven einzusetzen. Der Vortrag rekonstruiert die Natur- und Kulturgeschichte der Kleidermotte anhand ökologischer Studien und historischen Indizien. T2 - Konservierungswissenschaft im Dialog Rathgen Forschungslabor CY - Berlin, Germany DA - 30.01.2018 KW - IPM KW - Museum KW - Biologische Bekämpfung KW - Kulturgut PY - 2018 AN - OPUS4-43988 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Plarre, Rüdiger T1 - Termiten in Deutschland - wo gibt es denn so was? N2 - Rare occurrences of termites in Germany. Termites are typical elements of the tropical and subtropical insect fauna. In Europe, their most northern natural range is southern France, Italy and the South-Balkan region. Only occasionally are termites found in Germany. Their occurrence is always very closely associated with the synanthropic environment. Drywood termites like Cryptotermes brevis or Kalotermis flavicollis were accidentally imported with furniture, wooden artefacts or plant material into homes or indoor arboretums. Similar pathways of termite introduction are described for Coptotermes gestroi and Reticulitermes sp. into tropical botanical gardens and tropical theme parks. Although termites were introduced to Germany several times, successful spreading or long term establishment never occurred due to climatic barriers, namely cold winter temperatures. Only Reticulitermes flavipes formed sustainable colonies in the city of Hamburg for several decades. Originating from the eastern United States of America, this species was introduced in the 1930s with infested wood through the sea port. Small subterranean colonies could survive the winter in areas where pipes of the central heating system kept the ground from freezing. Control efforts of this potentially invasive species of economic importance started early on but failed until modern bait techniques were applied in the year 2000. Currently, termites have not been detected in Hamburg for the last five years. KW - Holzschutz KW - Termiten KW - Neozoon PY - 2018 SN - 0037-5942 VL - Neue Folge 53 SP - 83 EP - 90 PB - Gesellschaft Naturforschender Freunde zu Berlin CY - Berlin AN - OPUS4-44055 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Plarre, Rüdiger T1 - Nationale und internationale Normung - was ist wichtig, was ist neu N2 - Normativ ist der Holzschutz in Deutschland durch die DIN 68800-Reihe geregelt. Die Normungsarbeit in CEN/TC 38 bildet dafür den Rahmen, der national angepasst und fachspezifisch erweitert wurde. Zusammen mit dem Kommentar ergeben beide ein in Europa einzigartiges Regelkompendium im Holzschutz. In Zukunft wird die Regelsetzung noch stärker durch internationale Zusammenarbeit bestimmt sein. Der interkontinentalen Marktöffnung sollten Verständigungen auf gemeinsame Qualitätsstandards vorausgehen. T2 - Holzschutztagung Deutsche Bauchemie 2019 CY - Kassel, Germany DA - 21.11.2019 KW - Normung KW - Europa KW - Holzschutz PY - 2019 AN - OPUS4-49724 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Plarre, Rüdiger T1 - Das Insektennarrativ in der Unterhaltungsliteratur und der Ursprung der Engelsflügel N2 - Viele Menschen erfreuen sich an Schmetterlingen. Besonders die farbfrohen Tagfalter lösen angenehme Gefühle aus. In der kulturellen Entomologie haben Schmetterlinge daher einen hohen Stellenwert, so auch in der schöngeistigen Literatur. Eine aktuelle stichprobenartige Untersuchung von 54 Büchern der deutschsprachigen Belletristik mit Insektenbezug im Titel oder auf dem Cover zeigte, dass sich zwei Drittel von ihnen des Schmetterlingnarrativs bedienten. Die folgende Analyse setzte das Ergebnis in einen historischen Bezug zur Verwendung von Insektenvorbildern in der Unterhaltungsliteratur und in Autorenbiografien. Die besondere Stellung der Schmetterlinge wird dabei geschichtlich als Relikt einer kulturellen Genese mit mythologisch-religiösen Wurzeln interpretiert. Im antiken Griechenland wurde die Bezeichnung Psyche mit bewusster Doppelbedeutung für Schmetterling und Seele verwendet. Im Hellenismus wurden die Seele und Seelenwesen wie z. B. die Daimons (Genien) oftmals mit Schmetterlingsflügeln dargestellt. Auch in den levantinischen Religionen wurden einzelne Gottheiten und Schutzgeister mit Flügeln nach Schmetterlingsart, jedoch aus Vogelfedern bestehend, abgebildet. Mit der Entstehung und Verbreitung der monotheistischen Lehren gingen viele dieser geflügelten Glaubenswesen dann in die Engelschöre über. Auch wenn die Flügel der Engel letztendlich wahrscheinlich von denen der Vögel abzuleiten sind, bleibt ein starker emotionaler Bezug zu den Schmetterlingen, der weit über den rein ästhetischen ausstrahlt. KW - Religion KW - Kulturelle Entomologie KW - Schmetterlinge KW - Flügel PY - 2021 DO - https://doi.org/10.25671/GNF_Sber_NF_55_02 SN - 0037-5942 VL - 55 SP - 31 EP - 53 AN - OPUS4-52950 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Plarre, Rüdiger ED - Trematerra, P. ED - Conti, B. T1 - Uninvited and welcomed guests in museums – biological management of clothes moths and woodworms N2 - In museums and historic houses clothes, moths (Tineola bisselliella, Tinea pellionella) and the furniture beetle (Anobium punctatum) are the most economically important pests on textiles or wooden artifacts, respectively. Their management is essential to protect cultural ethnological heritage and natural history collections for future generations. Pest management strategies have changed over time. Today, intensive knowledge on pest biology and overall material science are key cornerstones in IPM concepts - also for the Museum environment. The important first steps for sustainable pest management are risk assessment, early pest detection and identification of pathways of infestation. These steps are followed by physical and biological means of control, which have lately gained more importance than applying biocides. Several potentially effective biological enemies of clothes moths and woodworm have been known for a long time, but their promotion for pest control in Museums and historic houses is just beginning. This short review summarizes current concepts of pest life cycle interruption by applying good quarantine and very specific biological measures. The lessons learned from recent faunistic surveys, life-history studies as well as behavioral observations of parasitoids and predators of clothes moths and woodworm may supplement the pest management tool box. The need for further research in this field is addressed. T2 - Working Group Meeting "Integrated Protection of Stored Products" CY - Pisa, Italy DA - 03.09.2019 KW - Corynetes caeruleus KW - Biological control KW - Museum pests KW - Tineola bisselliella KW - Anobium punctatum KW - Apanteles carpatus KW - Baryscapus tineivorus PY - 2020 SN - 978-92-9067-333-0 VL - 148 SP - 266 EP - 273 AN - OPUS4-50543 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Plarre, Rüdiger T1 - Klopf auf Holz! … weil es gut und dauerhaft ist – und was trägt die Normung dazu bei? N2 - Die Bewertung der Dauerhaftigkeit von Holz und Holzprodukten ist ein zentrales Thema im Holzschutz. Es wird zwischen einer natürlichen und einer herbeigeführten Dauerhaftigkeit unterschieden. Die Norm DIN EN 350 trägt beiden Richtungen Rechnung. Die Anwendung der Norm wird in vielen Fällen aber nicht korrekt durchgeführt. Schwachstellen werden diskutiert. T2 - Fortbildungsveranstaltung des Deutschen Holzschutzverbandes CY - Online meeting DA - 21.01.22 KW - Holzschutz KW - Dauerhaftigkeit KW - DIN EN 350 PY - 2022 AN - OPUS4-54298 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pietsch, Franziska A1 - Schreiber, Frank A1 - Heidrich, Gabriele T1 - Selection of resistance in bacterial biofilms grown on antimicrobial surfaces in a multidrug environment N2 - Introduction: Biofilms are regarded as a common cause of chronic infections on medical devices. Preventive and therapeutic strategies against biofilm infections commonly involve applications of multiple antimicrobial substances: antimicrobial coatings on the implanted biomaterials in combination with systemically administered antibiotics. While this practice of combination therapy harbours the risk of developing cross-resistance, it might also provide the possibility to implement specific antimicrobial-antibiotic combinations (AACs) that can slow down the selection of antibiotic resistant strains. Hypothesis and aims: Specific AACs can exert combinatorial effects on the growth of susceptible and antibiotic-resistant Pseudomonas aeruginosa that either suppress or increase their individual effects. Our aim is to identify AACs with antagonistic or synergistic effects on pseudomonal biofilms and to understand their impact on selection of resistant strains. Specifically, we want to identify AACs that select for and against antibiotic resistance during biofilm formation. Methodology: We screened for AACs that cause antagonistic or synergistic effects on planktonic P. aeruginosa. To study the effect of antimicrobial-antibiotic exposure on resistance selection in bacterial biofilms, we will grow resistant and sensitive strains on PDMS surfaces with and without antimicrobial coatings and expose them to antibiotics. Results: Several combinations with synergistic or antagonistic interaction on the growth rate of P. aeruginosa were detected. We observed a strong antagonism when combining the antimicrobial substance chlorhexidine with the carbapenem drug meropenem. A meropenem-resistant mutant showed a selection advantage in low concentrations of chlorhexidine combined with a sub-inhibitory concentration of meropenem over the wild-type. No antagonistic effect was observed for the same combination when E. coli was exposed to chlorhexidine and meropenem, suggesting a non-chemical basis for the observed effect on P. aeruginosa. Conclusion: Gaining a better understanding about resistance selection during biofilm formation on biomedical surfaces will enable us to mitigate against biofilm-associated antimicrobial resistance. T2 - Eurobiofilms 2019 CY - Glasgow, UK DA - 03.09.2019 KW - Resistance KW - Antibiotics KW - Pseudomonas PY - 2019 AN - OPUS4-49168 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pietsch, Franziska A1 - Schreiber, Frank T1 - Selection of Resistance in Bacterial Biofilms Grown on Antimicrobial Surfaces in a Multidrug Environment N2 - Background Bacterial biofilms are regarded as the most common cause of chronic infections and are often associated with medical devices, such as implants and catheters. Bacteria growing in biofilms produce a protective, extracellular matrix, which enables them to tolerate much higher antimicrobial concentrations than free-living bacteria and survive long enough to acquire antimicrobial resistance. Preventive and therapeutic strategies against biofilm infections in clinical settings commonly involve the application of multiple antimicrobials: biocidal coatings on the biomaterials and systemically administered antibiotics. This frequent practice harbors the risk of the development of cross-resistance via shared resistance mechanisms between antimicrobials used in material coatings and administered antibiotics. Aim Our goal is to determine how bacteria adapt to antimicrobials during biofilm formation on surfaces coated with antimicrobials, how antimicrobial resistance mutations are acquired and evolve within mature biofilms, and how population dynamics within biofilms affect the transmission of resistance mutations. Specifically, we want to identify antimicrobial-antibiotic-combinations that select for and against antibiotic resistance in biofilms by following the population dynamics of resistant and susceptible strains in competition assays. Methodology We will grow biofilms of Pseudomonas aeruginosa on glass surfaces with and without antimicrobial coatings and expose them to antibiotics. Then we will track their physiological properties, evolutionary adaptations, and population dynamics. First, we will screen in vitro for combinations of antibiotics and antimicrobials that select for and against antibiotic resistance. Second, effective combinations will be chosen for in-depth investigations during bacterial adhesion and of mature biofilms of resistant and susceptible genotypes. Third, based on the outcome of the screen and the obtained mechanistic understanding we will choose a clinical example in which we study the relevance of our findings in biofilms grown in vivo. Relevance Studying the biointerfacial interactions between bacterial biofilms and medical devices in terms of population dynamics as well as on single cell level during multidrug selection will help us understand how drug resistance develops and spreads in persistent biofilm infections. Based on our findings we aim to provide clinical recommendations for improved administration of antibiotics/antimicrobials in combination with medical device materials in order to mitigate against biofilm associated antimicrobial resistance. T2 - Challenges and New Concepts in Antibiotic Research CY - Paris, France DA - 19.03.2018 KW - Resistance KW - Antimicrobials PY - 2018 AN - OPUS4-46398 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pietsch, Franziska A1 - Schreiber, Frank T1 - Selection of resistance in bacteria grown on antimicrobial surfaces in a multidrug environment N2 - Bacterial biofilms are regarded as the most common cause of chronic infections and are often associated with medical devices, such as implants and catheters. Bacteria growing in biofilms produce a protective, extracellular matrix, which enables them to tolerate much higher antimicrobial concentrations than free-living bacteria and survive long enough to acquire antimicrobial resistance. Preventive and therapeutic strategies against biofilm infections in clinical settings commonly involve the application of multiple antimicrobials: antimicrobial coatings on the biomaterials and systemically administered antibiotics. This frequent practice harbors the risk of the development of cross-resistance via shared resistance mechanisms between antimicrobials used in material coatings and administered antibiotics. Our goal is to determine how population dynamics within biofilms affect the transmission of resistance mutations. Specifically, we want to identify antimicrobial-antibiotic-combinations that select for and against antibiotic resistance in biofilms by following the population dynamics of resistant and susceptible strains in competition assays. Gaining a better understanding about resistance development and spread in persistent biofilm infections will enable us to provide clinical recommendations for improved administration of antibiotics/antimicrobials in combination with medical device materials to mitigate against biofilm associated antimicrobial resistance. Here, we will discuss our first findings on the effects of combinations of the carbapenem drug meropenem and various antimicrobials. T2 - The Antimicrobial Resistance on Biomaterials Workshop CY - St. Gallen, Switzerland DA - 25.10.2018 KW - Resistance KW - Antimicrobials PY - 2018 AN - OPUS4-46526 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pietsch, Franziska A1 - Schreiber, Frank T1 - Selection of resistance in bacterial biofilms grown on antimicrobial surfaces in a multidrug environment N2 - Background Bacterial biofilms are regarded as the most common cause of chronic infections and are often associated with medical devices, such as implants and catheters. Bacteria growing in biofilms produce a protective, extracellular matrix, which enables them to tolerate much higher antimicrobial concentrations than free-living bacteria and survive long enough to acquire antimicrobial resistance. Preventive and therapeutic strategies against biofilm infections in clinical settings commonly involve the application of multiple antimicrobials: biocidal coatings on the biomaterials and systemically administered antibiotics. This frequent practice harbors the risk of the development of cross-resistance via shared resistance mechanisms between antimicrobials used in material coatings and administered antibiotics. Aim Our goal is to determine how bacteria adapt to antimicrobials during biofilm formation on surfaces coated with antimicrobials and how population dynamics within biofilms affect the transmission of resistance mutations. Specifically, we want to identify antimicrobial-antibiotic-combinations that select for and against antibiotic resistance in biofilms by following the population dynamics of resistant and susceptible strains in competition assays on a single cell level. Methodology To study the effect of antimicrobial-antibiotic exposure on resistance development and population dynamics on bacterial biofilms in a multidrug environment, we will grow Pseudomonas aeruginosa on glass surfaces with and without antimicrobial coatings and expose them to antibiotics. First, we will screen in vitro for combinations of antibiotics and antimicrobials that select for and against antibiotic resistance. Second, effective combinations will be chosen for in-depth investigations during bacterial adhesion and of mature biofilms of resistant and susceptible genotypes. Third, based on the outcome of the screen and the obtained mechanistic understanding we will choose a clinical example in which we study the relevance of our findings in biofilms grown in vivo. Relevance Studying the biointerfacial interactions between bacterial biofilms and medical devices in terms of population dynamics as well as on single cell level during multidrug selection will help us understand how drug resistance develops and spreads in persistent biofilm infections. Based on our findings we aim to provide clinical recommendations for improved administration of antibiotics/antimicrobials in combination with medical device materials in order to mitigate against biofilm associated antimicrobial resistance. T2 - Biofilms 8 Conference CY - Aarhus, Denmark DA - 27.05.2018 KW - Resistance KW - Antimicrobials PY - 2018 AN - OPUS4-46524 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Piechotta, Christian A1 - Iznaguen, Hassan A1 - Traub, Heike A1 - Feldmann, Ines A1 - Köppen, Robert A1 - Witt, Angelika A1 - Jung, Christian A1 - Becker, Roland A1 - Oleszak, Katrin A1 - Bücker, Michael A1 - Urban, Klaus A1 - Reger, Christian A1 - Ostermann, Markus T1 - Bewitterungsszenarien im Vergleich – Veränderungen in der Oberflächenmorphologie von Polypropylen (PP) und Polystyrol (PS) unter dem Aspekt des Austrags von polybromierten Flammschutzmitteln N2 - Gegenstand der vorzustellenden Arbeiten ist die Prüfung der Umwelt-beständigkeit und -verträglichkeit von Materialien und Produkten hinsichtlich der Emission von potenziellen Schadstoffen in die Umwelt. Hierzu werden chemisch-physikalische Einflüsse (Bewitterung) und mikrobielle Beanspruchungen an Modellmaterialien evaluiert. So werden die Freisetzungsraten von Schadstoffen in Abhängigkeit der Beanspruchung beschrieben. Als Modellmaterialien kommen die Polymere Polystyrol (PS) und Polypropylen (PP) zum Einsatz. Synergistische Effekte der Bewitterungsparameter und der mikrobiologischen Beanspruchung sollen dabei ebenso betrachtet werden, wie die gezielte Alterung. Auch findet eine Beschreibung des Verhaltens der ausgetragenen Schadstoffe in den Umweltkompartimenten Boden oder Wasser statt. Hier sind mit Hilfe der zu entwickelnden Screening- und non-Target-Analyseverfahren die Transformation und der Metabolismus durch Mikroorganismen zu beschreiben. Aus den Ergebnissen sollen Korrelationen zwischen den künstlichen Alterungsverfahren und realen Szenarien abgeleitet werden. T2 - 47. Jahrestagung der GUS CY - Blankenloch-Stutensee, Germany DA - 21.03.2018 KW - Schadstoffaustrag KW - Umweltsimulation KW - Bewitterung PY - 2018 SN - 978-981-18507-2-7 VL - 47 SP - 115 EP - 128 AN - OPUS4-49802 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Piechotta, Christian A1 - Iznaguen, H. A1 - Traub, Heike A1 - Feldmann, Ines A1 - Köppen, Robert A1 - Witt, Angelika A1 - Jung, Christian A1 - Becker, Roland A1 - Oleszak, K. A1 - Bücker, Michael A1 - Urban, Klaus A1 - Reger, Christian A1 - Ostermann, Markus T1 - Bewitterungsszenarien im Vergleich – Veränderungen in der Oberflächenmorphologie von Polypropylen (PP) und Polystyrol (PS) unter dem Aspekt des Austrags von polybromierten Flammschutzmitteln N2 - In addition to previously reported results on the simulated aging of polystyrene samples (PS) containing 1 wt. % hexabromocyclododecane (HBCD), we present the first results of our investigations of polypropylene (PP)-samples containing 0.1 wt. % BDE-209. All studied polymer samples were exposed to a defined weathering schedule in a climate chamber in accordance to regulation EN ISO 4892-3:2006.For the determination of BDE-209 in the collected rain water samples derived from the used climate chamber, the samples were prepared in accordance with a validated protocol. Before the analyses, each sample was spiked with 2 µL of isotopically labeled BDE-209 (13C10-BDE-209) to serve as internal standard (ISTD) in the performed stable isotope dilution analysis. Subsequently the samples were extracted with isooctane, the obtained aliquots of the extracts were concentrated to 200 µL and 2 µL of the resulting solution were injected to the GC/MS for quantification. Additionally, the total bromine contents are monitored for the aged and untreated samples using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) as well as X-ray fluorescence analysis (XRF) as non-destructive and rapid method. Furthermore, results from surface analysis using environmental scanning electron microscopy (ESEM) for morphological characterization of the aged and untreated samples were presented and discussed. In general, the resulting data from the accelerated aging will be compared to those from the natural weathering experiments (“atmospheric exposure”, in soil). The atmospheric exposure was performed by placing the samples on a weathering rack, which is aligned in SW direction (in a 45° angle to the horizon). The weathering data were regularly recorded by Deutscher Wetterdienst at this site. The surfaces of the test specimens (aged and stored references) were analyzed by ESEM as well as by LA-ICP-MS and by XRF. The surface of PS and PP specimens aged outdoors present the aging under real conditions and allow the comparison to the accelerated aged specimens by means of the weathering chamber. This way, we explore the efficiency of the accelerated aging procedure, which provides the advantage of well-defined and reproducible conditions compared to natural weathering, as a tool for testing different plastic materials. Additionally “in soil” experiments were conducted in-door in a well characterized testing soil. The soil (boulder-clay, sand with 12 % loam, particle size in total 0.2-4 mm) is filled in a free-draining concrete basin inside of an air-conditioned room. In this manner, TOC, water capacity and humidity are recorded parameters. To assure a washing out process from the samples by the raining water, the target water content is calculated to 8%. The actual humidity is measured by a tensiometer, assuring the duration of the raining period. The water content is additionally monitored by weight of the basin, capturing water from raining periods. The correct humidity is a fundamental parameter for biological activity. Samples of PS resp. PP were of dimension 10x1cm and 5 specimens were placed up to the half in the soil per basin. Microbial activity of the soil, monitored by the reference polyurethane, sets HBCD resp. BDE-209 of the samples free and will be leached from the samples by raining water. Thereafter these will be captured by passive samplers placed in a distinct distance to the samples in the soil. The “in soil” experiments are complementary to the weathering experiments due to the biological activity in the soil. These experiments simulate the fate of the brominated flame retardants in the biosphere. N2 - Gegenstand der vorzustellenden Arbeiten ist die Prüfung der Umweltbeständigkeit und -verträglichkeit von Materialien und Produkten hinsichtlich der Emission von potenziellen Schadstoffen in die Umwelt. Hierzu werden chemisch-physikalische Einflüsse (Bewitterung) und mikrobielle Beanspruchungen an Modellmaterialien evaluiert. So werden die Freisetzungsraten von Schadstoffen in Abhängigkeit der Beanspruchung beschrieben. Als Modellmaterialien kommen die Polymere Polystyrol (PS) und Polypropylen (PP) zum Einsatz, die jeweils mit polybromierten Flammschutzmitteln (PBFSM) versehen sind. Synergistische Effekte der Bewitterungsparameter und der mikrobiologischen Beanspruchung sollen dabei ebenso betrachtet werden, wie die gezielte Alterung. Auch findet eine Beschreibung des Verhaltens der ausgetragenen Schadstoffe in den Umweltkompartimenten Boden oder Wasser statt. Hier sind mit Hilfe der zu entwickelnden Screening- und non-Target-Analyseverfahren die Transformation und der Metabolismus durch Mikroorganismen zu beschreiben. Auch soll mit Hilfe der RFA und der LA-ICP-MS die Abreicherung der PBFSM in den Modellmaterialien beschrieben werden. Aus den Ergebnissen sollen Korrelationen zwischen den künstlichen Alterungsverfahren und realen Szenarien abgeleitet werden. T2 - 47. Jahrestagung der GUS 2018 CY - Stutensee - Blankenloch, Germany DA - 21.03.2018 KW - Polypropylen KW - Polystyrol KW - Flammschutzmittel KW - XRF KW - LA-ICP-MS PY - 2018 AN - OPUS4-47024 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Piechotta, Christian A1 - Iznaguen, H. A1 - Traub, Heike A1 - Feldmann, Ines A1 - Köppen, Robert A1 - Witt, Angelika A1 - Jung, Christian A1 - Becker, Roland A1 - Oleszak, K. A1 - Bücker, Michael A1 - Urban, Klaus A1 - Reger, Christian A1 - Ostermann, Markus T1 - TF-Projekt MaUS: Material und Umweltsimulation N2 - Gegenstand des Projekts ist die Prüfung der Umweltbeständigkeit und -verträglichkeit von Materialien und Produkten hinsichtlich der Emission von potenziellen Schadstoffen in die Umwelt. Hierzu werden chemisch-physikalische Einflüsse (Bewitterung) und mikrobielle Beanspruchungen an Modellmaterialien evaluiert. So werden die Freisetzungsraten von Schadstoffen in Abhängigkeit der Beanspruchung beschrieben. Als Modellmaterialien kommen die Polymere Polycarbonat, Polytetrafluorethylen, Polystyrol und Polypropylen zum Einsatz. Synergistische Effekte der Bewitterungsparameter und der mikrobiologischen Beanspruchung sollen dabei ebenso betrachtet werden, wie die gezielte Alterung. Auch findet eine Beschreibung des Verhaltens der ausgetragenen Schadstoffe in den Umweltkompartimenten Boden oder Wasser statt. Hier sind mit Hilfe der zu entwickelnden Screening- und non-Target-Analyseverfahren die Transformation und der Metabolismus durch Mikroorganismen zu beschreiben. Aus den Ergebnissen sollen Korrelationen zwischen den künstlichen Alterungsverfahren und realen Szenarien abgeleitet werden, die es gestatten, Schnellprüfverfahren zu etablieren, die die Simulation der realen Beanspruchungen im Zeitraffermodell anwendbar machen. Somit sollen standardisierbare Schnellbeanspruchungs-verfahren erarbeitet werden, die als Prüfeinrichtungen etabliert werden und von externen Auftraggebern zur Prüfung der Umweltbeständigkeit und -verträglichkeit von neuen Materialien genutzt werden können. Die Umweltwirkungen (chemisch-physikalisch und mikrobiologisch) sollen so definiert eingesetzt werden, dass eine reproduzierbare Prüfung möglich wird. Aus diesen Verfahren und Methoden sollen Normen abgeleitet werden, die eine standardisierte Materialprüfung ermöglichen. T2 - Projektmeeting BAM - Covestro CY - Leverkusen, Germany DA - 29.05.2018 KW - Umweltsimulation KW - Schadstoffaustrag PY - 2018 AN - OPUS4-47025 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Piechotta, Christian A1 - Iznaguen, H. A1 - Traub, Heike A1 - Feldmann, Ines A1 - Köppen, Robert A1 - Witt, Angelika A1 - Jung, Christian A1 - Becker, Roland A1 - Oleszak, K. A1 - Bücker, Michael A1 - Urban, Klaus A1 - Reger, Christian A1 - Ostermann, Markus T1 - Environmental sustainability and –stability of Materials concerning the Migration of pollutants N2 - MaUS is an acronym for ”Material und Umweltsimulationen“. Plastics are in the focus of environmental politics due to their long-term behaviour and therefore to their persistence. Not only that they appear as visible contaminants in the sea and on the beach, but their unknown behaviour concerning their additives as well as the related transformation products are anxious. Therefore, we wish to establish a certified reference method to provide a method for testing plastics. Aim of this project is the development of fast motion standard reference methods for testing plastics regarding to their environmental compatibility. To establish these testing methods, we use polystyrene (PS) and polypropylene (PP) with environmental relevant brominated flame retardants, known for their persistent bioaccumulative and toxic (PBT) properties. In case of PS the material contains 1 wt% of 1,2,5,6,9,10-hexabromocyclododecan (HBCD) and in case of PP 0.1 wt% bromodiphenylether (BDE-209), which is known as a substance of very high concern (SVHC). Furthermore, we use polycarbonate (PC), which is still used as material in baby flasks and releases Bisphenol A (BPA), an estrogenic active substance. As an additional material PTFE is used for its importance as a source for two ubiquitous environmental substances (PFOS and PFOA), whose toxicological effects are still incompletely known. The focus in this current work is set on the transfer of potential pollutants out of applied materials mentioned above into environmental compartments like water or soil. Here an accelerated aging concept should be developed to shortened time consuming natural processes. For these resulting simulations we use a programmable weathering chamber with dry and wet periods and with high and low temperatures. These programmes run for several weeks and according to a defined sampling schedule we take water samples, run a clean-up procedure by SPE (Molecular imprinted polymers (MiPs) resp. polymer-based cartridges (Waters Oasis HLB)) and analyse them by HPLC-UV resp. LC-MS/MS. Of most interest in case of flame retardants are photocatalytic transformation products. Therefore, we conduct a non-target-screening resp. a suspected target-screening by LC-MS/MS and HRMS. T2 - Project meeting PlasticsEurope - BAM CY - Leverkusen, Germany DA - 06.11.2018 KW - Environmental simulation KW - Pollutants PY - 2018 AN - OPUS4-47026 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Piechotta, Christian A1 - Traub, Heike A1 - Ostermann, Markus A1 - Becker, Roland A1 - Köppen, Robert A1 - Bücker, Michael A1 - Reger, Christian T1 - LA-ICP-MS- und RFA-Messungen für die Bestimmung von polybromierten Flammschutzmitteln(PBFSM) in Polystyrol- und Polypropylenproben N2 - Gegenstand der vorzustellenden Arbeiten ist die Prüfung der Umwelt-beständigkeit und -verträglichkeit von Materialien und Produkten hinsichtlich der Emission von potenziellen Schadstoffen in die Umwelt. Hierzu werden chemisch-physikalische Einflüsse (Bewitterung) und mikrobielle Beanspruchungen an Modellmaterialien evaluiert. So werden die Freisetzungsraten von Schadstoffen in Abhängigkeit der Beanspruchung beschrieben. Als Modellmaterialien kommen die Polymere Polystyrol (PS) und Polypropylen (PP) zum Einsatz. Synergistische Effekte der Bewitterungsparameter und der mikrobiologischen Beanspruchung sollen dabei ebenso betrachtet werden, wie die gezielte Alterung. Auch findet eine Beschreibung des Verhaltens der ausgetragenen Schadstoffe (polybromierte Flammschutzmittel) in den Umweltkompartimenten Boden oder Wasser statt. Hier sind mit Hilfe der zu entwickelnden Screening- und non-Target-Analyseverfahren die Transformation und der Metabolismus durch Mikroorganismen zu beschreiben. Aus den Ergebnissen sollen Korrelationen zwischen den künstlichen Alterungsverfahren und realen Szenarien abgeleitet werden. T2 - Kolloquium "Aquatische Ökologie" CY - Essen, Germany DA - 27.11.2019 KW - Umweltsimulation KW - PBFSM KW - LA-ICP-MS KW - RFA PY - 2019 AN - OPUS4-49975 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Piechotta, Christian A1 - Köppen, Robert A1 - Becker, Roland A1 - Traub, Heike A1 - Ostermann, Markus A1 - Bücker, Michael A1 - Reger, Christian A1 - Westphalen, Tanja T1 - Environmental sustainability and –stability of materials concerning the migration of pollutants N2 - In addition to previously reported results on the accelerated weathering of polystyrene samples (PS) containing 1 wt. % hexabromocyclododecane (HBCD), we present the first results of our investigations of polypropylene samples (PP) containing 0.1 wt. % BDE-209. All studied polymer samples were exposed to a defined weathering schedule in a climate chamber in accordance to regulation EN ISO 4892-3:2006. For the determination of BDE-209 in the collected raining water the samples were prepared in accordance to a validated protocol. Before the analyses each sample was spiked with isotopically labeled BDE-209. Subsequently the samples were extracted with isooctane. The obtained extracts were concentrated, and the resulting solutions were analyzed by GC/MS. Additionally, the total bromine content was monitored for the weathered and untreated samples using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and X-ray fluorescence analysis (XRF) as a non-destructive and rapid method. In general, the resulting data from the accelerated weathering will be compared to those from the natural weathering experiments. Here, the surfaces of the test pieces were analyzed by LA-ICP-MS and XRF as well. Moreover, soil bed tests were conducted in a well characterized model soil. This soil (boulder-clay, sand with 12 % loam, particle size in total 0.2-4 mm) is filled in a free-draining basin inside of an air-conditioned cellar. In this manner, TOC, water capacity and humidity are recorded parameters. To induce a leaching process from the samples by the raining water, the target water content is calculated to 8%. The actual humidity is measured by a tensiometer, assuring the duration of the raining period. A defined humidity is a fundamental parameter for a biological activity in the soil. The test polymers were placed up to the half in the soil. Microbial activity of the soil is monitored by a reference polymer (polyurethane) and should induce the release of HBCD and BDE-209 out of the test materials. These released analytes will be captured by passive samplers (silicone tubes) placed in a distinct distance to the polymer samples in the soil. The soil bed experiments are complementary to the weathering experiments due to the biological activity in the soil. T2 - Goldschmidt 2019 CY - Barcelona, Spain DA - 18.08.2019 KW - Pollutants KW - Environmental simulation KW - Migration PY - 2019 AN - OPUS4-49803 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Palanti, S. A1 - Cragg, S. A1 - Plarre, Rüdiger T1 - Resistance against marine borers: About the revision of EN 275 and the attempt for a new laboratory standard for Limnoria N2 - Wood protection technology in the marine environment has changed over the last decades and will continue to do so. New active ingredients, newer formulations, and novel wood-based materials including physically- and chemically-modified wood, together with increasing concerns over environmental impacts of wood preservatives, urgently demand a major revision of EN 275 “Wood preservatives – Determination of the Protective Effectiveness against Marine Borers”, dated from 1992. This IRG document reports on the technical work in CEN TC 38 regarding the revision of this standard. A Task Group within WG 24 of CEN TC 38 was formed consisting of experts from different field of competence (e.g. wood preservatives industry, wood scientists, marine biologists, archaeologists and cultural heritage conservators). Starting by e-mail correspondence in 2014, and continuing with four physical meetings (Berlin 2x, Florence, Venice) with experts from Germany, Italy, Sweden, and UK were held so far. Significant items for revision in EN 275 were identified as: number of replicates, duration of the test, dimension of specimens, number of test sites, number of reference species, reference material including reference preservative, re-immersion of specimens after non-destructive periodical evaluation for longer periods of time vs higher number of replicates for successive destructive examinations without re-immersion, utilization of X- ray apparatus and specific software to ease evaluation, etc. Furthermore, the task group is working on a standardized lab test for time-saving evaluation of different wood qualities for their potential to resist attack by limnorids. The suitability of this lab test will be determined by round robin tests as soon as safe face-to-face collaboration permits. The outcome will be published as a CEN TR (Technical Report) document, with a view to eventual adoption within the revised standard. T2 - THE INTERNATIONAL RESEARCH GROUP ON WOOD PROTECTION CY - Online meeting DA - 10.06.2020 KW - Standardization KW - Marine borers KW - Bankia sp KW - Teredo sp KW - Limnoria spp KW - Durability PY - 2020 VL - 2020 SP - IRG/WP 20-20669-1 EP - IRG/WP 20-20669-11 CY - Stockholm AN - OPUS4-52064 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Olbrich, Adelina-Elisa A1 - An Stepec, Biwen Annie A1 - Koerdt, Andrea A1 - Meermann, Björn T1 - Deciphering microbiological influenced corrosion processes on steel with single cell-ICP-ToF-MS N2 - Microbiologically influenced corrosion (MIC) is a highly unpredictable process dictated by the environment, microorganisms, and the respective electron source. Interaction pathways between cells and the metal surface remain unclear. The development of this novel single cell-inductively coupled plasma-time of flight-mass spectrometry analytical method and a MIC-specific staining procedure facilitate the investigation of steel-MIC interactions. With this it is possible to analyze the multi-elemental fingerprint of individual cells. The detection method revealed elemental selectivity for the corrosive methanogenic archaeal strain Methanobacterium-affiliated IM1. The interface between material and environmental analysis thus receives special attention, e.g., when considering MIC on solid steel. Hence, the possible uptake of individual elements from different steel samples is investigated. Results showed the cells responded at a single-cell level to the different types of supplemented elements and displayed the abilities to interact with chromium, vanadium, titanium, cobalt, and molybdenum from solid metal surfaces. The information obtained will be used in the future to elucidate underlying mechanisms and develop possible material protection concepts, thus combining modern methods of analytical sciences with materials research. References. T2 - Future WiNS CY - Berlin, Germany DA - 07.12.2022 KW - Single cell KW - Microbiological influenced corrosion MIC KW - Sc-ICP-ToF-MS KW - Method development KW - Ir DNA staining approach KW - Carbon steel corrosion PY - 2022 AN - OPUS4-56567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Olbrich, Adelina-Elisa A1 - An Stepec, Biwen Annie A1 - Koerdt, Andrea A1 - Meermann, Björn T1 - Material vs. Environment: Uncovering microbiological influenced corrosion processes on steel with single cell-ICP-ToF-MS N2 - Microbiologically influenced corrosion (MIC) is a highly unpredictable process dictated by the environment, microorganisms, and the respective electron source. Interaction pathways between cells and the metal surface remain unclear. The development of this novel single cell-inductively coupled plasma-time of flight-mass spectrometry analytical method and a MIC-specific staining procedure facilitate the investigation of steel-MIC interactions. With this it is possible to analyze the multi-elemental fingerprint of individual cells. The detection method revealed elemental selectivity for the corrosive methanogenic archaeal strain Methanobacterium-affiliated IM1. The interface between material and environmental analysis thus receives special attention, e.g., when considering MIC on solid steel. Hence, the possible uptake of individual elements from different steel samples is investigated. Results showed the cells responded at a single-cell level to the different types of supplemented elements and displayed the abilities to interact with chromium, vanadium, titanium, cobalt, and molybdenum from solid metal surfaces. The information obtained will be used in the future to elucidate underlying mechanisms and develop possible material protection concepts, thus combining modern methods of analytical sciences with materials research. T2 - ToFcon 2022 CY - Online meeting DA - 17.11.2022 KW - Single cell KW - Microbiological influenced corrosion MIC KW - Sc-ICP-ToF-MS KW - Method development KW - Ir DNA staining approach KW - Carbon steel corrosion PY - 2022 AN - OPUS4-56355 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Oberpaul, M. A1 - Zumkeller, C. M. A1 - Culver, T. A1 - Spohn, M. A1 - Mihajlovic1, S. A1 - Leis, B. A1 - Glaeser, S. P. A1 - Plarre, Rüdiger A1 - McMahon, Dino Peter A1 - Hammann, P. A1 - Schäberle, T. F. A1 - Glaeser, J. A1 - Vilcinskas, A. T1 - High-Throughput Cultivation for the Selective Isolation of Acidobacteria From Termite Nests N2 - Microbial communities in the immediate environment of socialized invertebrates can help to suppress pathogens, in part by synthesizing bioactive natural products. Here we characterized the core microbiomes of three termite species (genus Coptotermes) and their nest material to gain more insight into the diversity of termite-associated bacteria. Sampling a healthy termite colony over time implicated a consolidated and highly stable microbiome, pointing toward the fact that beneficial bacterial phyla play a major role in termite fitness. In contrast, there was a significant shift in the composition of the core microbiome in one nest during a fungal infection, affecting the abundance of wellcharacterized Streptomyces species (phylum Actinobacteria) as well as less-studied bacterial phyla such as Acidobacteria. High-throughput cultivation in microplates was implemented to isolate and identify these less-studied bacterial phylogenetic group. Amplicon sequencing confirmed that our method maintained the bacterial diversity of the environmental samples, enabling the isolation of novel Acidobacteriaceae and expanding the list of cultivated species to include two strains that may define new species within the genera Terracidiphilus and Acidobacterium. KW - Termite-associated microbes KW - Termites KW - Coptotermes KW - Core microbiome KW - Natural products discovery KW - Acidobacteria KW - underexplored phyla KW - Social insects PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-515283 DO - https://doi.org/10.3389/fmicb.2020.597628 VL - 11 SP - 1 EP - 16 AN - OPUS4-51528 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Oberpaul, M. A1 - Spohn, M. A1 - Fracowiak, J. A1 - Plarre, Rüdiger A1 - McMahon, Dino Peter A1 - Hammann, P. A1 - Vilcinskas, A. A1 - Gläser, J. T1 - Exploiting termite nest microbiomes for antibiotic discovery by using an ultra-high throughput Microfluidics/FACS driven pipeline combined with a microtiter plate based cultivation strategy N2 - Infections with multi-resistant Gram negative pathogens are a major threat to our health system. In order to serve the needs in antibiotics development we selected untapped bioresources and implemented high throughput approaches suitable for the discovery of strains producing antibiotics with anti-Gram negative activity. Our approaches rely on the hypothesis that Termite associated bacteria are likely to produce potent antibiotics to defend their hosts against entomopathogenic microorganisms. Termite nests and guts harbor suitable, highly diverse microbiomes in which bacterial taxa are present known to potentially produce natural compounds. In a first step the diversity of Coptotermes species nest microbiomes was assessed carefully by using 16S rDNA amplicon sequencing on the Illumina MiSeq platform and nest material was selected to retrieve viable cells by using Nycodenz density gradient centrifugation. In order to analyze the diversity of the culturable termite nest microbiome, bacterial cells were either distributed in 384-well plates (approach 1) or encapsulated in small spheric agarose beads by an high throughput microfluidics technique (approach 2). Cultures obtained from approach 1 were scaled-up in 96-well Duetz-systems for characterization of diversity and for rapid supernatant screening using the bioluminescence-labeled E. coli pFU166. The generated droplets of approach 2 simultaneously received a small population of GFP-tagged Gram negative screening cells and were sorted for low fluorescence using FACS. After elimination of redundancy we performed a fast scale-up of active strains. Implementation of this pipeline allows us to prioritize antibiotics producing strains in a ultra-high throughput fashion and by cultivation of broad diversity in our approches. T2 - Annual Conference of the Society for General and Applied Microbiology (VAAM) CY - Wolfsburg, Germany DA - 15.04.18 KW - Biotechnology KW - Termites KW - Anti-microbial effects PY - 2018 AN - OPUS4-44987 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas A1 - Schreiber, Frank A1 - Kanaris, Orestis A1 - Schmidt, Selina T1 - Persistence against benzalkonium chloride promotes rapid evolution of tolerance under periodic disinfection N2 - Biocides used as disinfectants are important to prevent the transmission of pathogens, especially during the current antibiotic resistance crisis. This crisis is exacerbated by phenotypically tolerant persister subpopulations which can survive transient antibiotic treatment and facilitate resistance evolution. Despite the transient nature of disinfection, knowledge concerning persistence to disinfectants and its link to resistance evolution is currently lacking. Here, we show that E. coli displays persistence against a widely used disinfectant benzalkonium chloride (BAC). Periodic, persister-mediated failure of disinfection rapidly selects for BAC tolerance. BAC tolerance is associated with reduced cell surface charge and mutations in the novel tolerance locus lpxM. Moreover, the fitness cost incurred by BAC tolerance turned into a fitness benefit in the presence of antibiotics, suggesting a selective advantage of BAC-tolerant mutants in antibiotic environments. Our findings provide a mechanistic underpinning for the faithful application of disinfectants to prevent multi-drug-resistance evolution and to steward the efficacy of biocides and antibiotics. T2 - World Microbe Forum (ASM, FEMS) CY - Online meeting DA - 20.06.2021 KW - Persistence KW - Biocides KW - Evolution KW - Cross-resistance KW - Biocide tolerance PY - 2021 AN - OPUS4-53167 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas A1 - Kanaris, Orestis A1 - Lewerenz, Dominique A1 - Gödt, Annett A1 - Schreiber, Frank T1 - Evolutionary implications of heterogeneous disinfectant tolerance N2 - Introduction: Effective disinfection is crucial to maintain hygiene and to prevent the spread of infections. Phenotypic heterogeneity in disinfection survival (i.e. tolerance) may result in failure of disinfection, which in turn may foster the evolution of resistance to both disinfectants and antibiotics. However, the consequences of phenotypic heterogeneity for disinfection outcome and resistance evolution are not well understood. Goal: This study investigates the impact of phenotypic heterogeneity on the survival and evolution of Escherichia coli during disinfection with six commonly used substances. Furthermore, the consequences of evolved disinfectant tolerance for antibiotic resistance evolution are studied. Materials & Methods: The extent of population heterogeneity during disinfection is derived by determining time-kill kinetics and analysis with mathematical modelling. The link between population heterogeneity and evolvability of disinfectant tolerance was assessed by laboratory evolution experiments under periodic disinfection. The ability of disinfectant tolerant strains to evolve antibiotic resistance is assessed by serial transfer experiments with increasing concentrations of different antibiotics and by whole genome sequencing. Results: Multi-modal time-kill kinetics in three of the six disinfectants suggest the presence of disinfectant-tolerant subpopulations (i.e. persister cells). Importantly, the ability and extent to evolve population-wide tolerance under periodic disinfection is related with the presence of persister cells and the level of phenotypic heterogeneity during disinfection. Interestingly, the probability of high-level resistance evolution to certain antibiotics is attenuated in disinfectant tolerant strains as compared to the sensitive ancestor. Whole-genome sequencing reveals epistatic interactions between disinfectant tolerance and antibiotic resistance mutations, preventing access to canonical evolutionary paths to resistance. Summary: Our findings suggest that phenotypic heterogeneity can facilitate disinfection survival and the evolution of population wide tolerance, which can impact future antibiotic resistance evolution. T2 - Vereinigung Allgemeiner und Angewandter Mikrobiobiologie Jahreskongress 2023 CY - Würzburg, Germany DA - 02.06.2024 KW - Biocide KW - Resistance KW - Persistence KW - Evolution KW - Herteogeneous phenotypes PY - 2024 AN - OPUS4-60244 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas A1 - Lewerenz, Dominique A1 - Schmidt, Selina A1 - Schreiber, Frank T1 - Heterogeneity in the bacterial response to disinfection and its impact on antibiotic tolerance and resistance N2 - The global rise of antibiotic resistance has made the proper use of disinfectants more important than ever. Their application in clinical l settings is an integral part of antibiotics stewardship by preventing the occurrence and spread of infections. However, improper use of disinfectants also harbours the risk for the evolution of tolerance and resistance to disinfectants, but also to antibiotics. It is therefore crucial to understand whether and how bacteria can survive chemical disinfection and which conditions facilitate the evolution of tolerance and resistance. Here, we study the heterogeneity in the response of isogenic E. coli populations exposed to different levels of commonly used disinfectants. At concentrations below the minimal inhibitory concentration (MIC), we find that certain disinfectants induce prolonged lag times in individual cells, a phenotype that has been associated with persistence against antibiotics. At concentrations above the MIC, we find heterogeneous killing for a range of the tested substances. Interestingly, for the three cationic surfactants that were tested, we find kill kinetics revealing the presence of a tolerant subpopulation that can withstand disinfection longer than most of the population. We will present results from an ongoing evolution experiment in which we test the potential for evolution of population-wide tolerance and resistance through intermittent exposure to lethal doses of a cationic surfactant. T2 - New Approaches and Concepts in Microbiology CY - Heidelberg, Germany DA - 10.07.2019 KW - Persistence KW - Biocides KW - Resistance KW - heterogeneity KW - Bacteria PY - 2019 AN - OPUS4-48524 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas A1 - Gustiherdini, Cahyaruri A1 - Lewerenz, Dominique A1 - Kanaris, Orestis A1 - Schreiber, Frank T1 - The disinfectant glutaraldehyde induces antibiotic tolerance N2 - Glutaraldehyde is widely used as a disinfectant and preservative, but little is known about its effects on bacterial susceptibility to antibiotics and the selection of tolerant phenotypes. We found that short-term exposure to sub-inhibitory levels of glutaraldehyde makes E. coli resistant to high doses of bactericidal antibiotics from different classes. This tolerance is associated with delayed, heterogeneous regrowth dynamics and global transcriptome remodeling. We identified over 1200 differentially expressed genes, including those related to antibiotic efflux, metabolic processes, and the cell envelope. The cells entered a disrupted state likely due to the unspecific mode-of-action of glutaraldehyde. Despite this unregulated response, we identified several differentially expressed genes not previously associated with antibiotic tolerance or persistence that induce antibiotic tolerance when overexpressed alone. These findings highlight how the unspecific mode-of-action of disinfectants can make bacteria temporarily resistant to antibiotics. They have implications for settings where disinfectants and antibiotics are used in close proximity, such as hospitals and animal husbandry, and for the selection dynamics of tolerant pheno- and genotypes in fluctuating environments where microorganisms are exposed to these substances, such as sewage systems. A trade-off arises from overcoming the disrupted state as quickly as possible and maintaining antibiotic tolerance. T2 - Gordon Research Conference - Molecular Mechanisms in Evolution CY - Easton, Massachusetts, United States DA - 25.06.2023 KW - Glutaraldehyde KW - Biocides KW - Tolerance KW - Bacteria KW - Disinfection KW - Heterogeneity KW - Antibiotics PY - 2023 AN - OPUS4-58033 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas T1 - EVOCIDE: Preserving disinfectant efficacy by predicting evolution: exposing the principles of disinfectant survival and adaptation in bacteria N2 - Presentation of the EVOCIDE research proposal work programme.EVOCIDE seeks to gain a systems level understanding of disinfectant survival and evolution in bacteria. T2 - Joint Group Seminar Rolff-McMahon-Armitage-Steiner CY - Berlin, Germany DA - 20.12.2023 KW - Disinfectants KW - Evolution KW - Microbiology KW - Bacteria KW - Biocides PY - 2023 AN - OPUS4-59224 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas T1 - The disinfectant glutaraldehyde induces antibiotic tolerance underpinned by phenotypic heterogeneity and transcriptome remodeling N2 - Glutaraldehyde is widely used as a disinfectant and preservative, but little is known about its effects on bacterial susceptibility to antibiotics and the selection of tolerant phenotypes. We found that short-term exposure to sub-inhibitory levels of glutaraldehyde makes E. coli resistant to high doses of bactericidal antibiotics from different classes. This tolerance is associated with delayed, heterogeneous regrowth dynamics and global transcriptome remodeling. We identified over 1200 differentially expressed genes, including those related to antibiotic efflux, metabolic processes, and the cell envelope. The cells entered a disrupted state likely due to the unspecific mode-of-action of glutaraldehyde. Despite this unregulated response, we identified several differentially expressed genes not previously associated with antibiotic tolerance or persistence that induce antibiotic tolerance when overexpressed alone. These findings highlight how the unspecific mode-of-action of disinfectants can make bacteria temporarily resistant to antibiotics. They have implications for settings where disinfectants and antibiotics are used in close proximity, such as hospitals and animal husbandry, and for the selection dynamics of tolerant pheno- and genotypes in fluctuating environments where microorganisms are exposed to these substances, such as sewage systems. A trade-off arises from overcoming the disrupted state as quickly as possible and maintaining antibiotic tolerance. T2 - µClub Seminar Series CY - Berlin, Germany DA - 26.05.2023 KW - Glutaraldehyde KW - Biocides KW - Tolerance KW - Bacteria KW - Disinfection KW - Heterogeneity PY - 2023 AN - OPUS4-58031 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas T1 - The disinfectant glutaraldehyde induces antibiotic tolerance underpinned by a Disrupted Cellular State and Heterogenous Regrowth Dynamics N2 - Glutaraldehyde is widely used as a disinfectant and preservative, but little is known about its effects on bacterial susceptibility to antibiotics and the selection of tolerant phenotypes. We found that short-term exposure to sub-inhibitory levels of glutaraldehyde makes E. coli resistant to high doses of bactericidal antibiotics from different classes. This tolerance is associated with delayed, heterogeneous regrowth dynamics and global transcriptome remodeling. We identified over 1200 differentially expressed genes, including those related to antibiotic efflux, metabolic processes, and the cell envelope. The cells entered a disrupted state likely due to the unspecific mode-of-action of glutaraldehyde. Despite this unregulated response, we identified several differentially expressed genes not previously associated with antibiotic tolerance or persistence that induce antibiotic tolerance when overexpressed alone. These findings highlight how the unspecific mode-of-action of disinfectants can make bacteria temporarily resistant to antibiotics. They have implications for settings where disinfectants and antibiotics are used in close proximity, such as hospitals and animal husbandry, and for the selection dynamics of tolerant pheno- and genotypes in fluctuating environments where microorganisms are exposed to these substances, such as sewage systems. A trade-off arises from overcoming the disrupted state as quickly as possible and maintaining antibiotic tolerance. T2 - Molecular Mechanisms in Evolution (GRS) Gordon Research Seminar CY - Easton, Massachusetts, USA DA - 24.06.2023 KW - Glutaraldehyde KW - Biocides KW - Tolerance KW - Bacteria KW - Disinfection KW - Heterogeneity KW - Antibiotics KW - AMR PY - 2023 AN - OPUS4-58032 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas A1 - Kanaris, Orestis A1 - Gustiherdini, Cahyaruri A1 - Lewerenz, Dominique A1 - Schreiber, Frank T1 - The disinfectant glutaraldehyde induces antibiotic tolerance underpinned by Phenotypic Heterogeneity and transcriptome remodeling N2 - Glutaraldehyde (GTA) is commonly used to disinfect medical equipment, in animal husbandry and in hydraulic fracturing. Its wide use bears the risk that microorganisms in different environments are exposed to potentially non-lethal doses of glutaraldehyde. To date, little is known about the effects of glutaraldehyde on the susceptibility of bacteria to antibiotics and its role in the selection of tolerant phenotypes. Objectives • To determine the effect of glutaraldehyde exposure on the survival of E. coli, S. aureus and P. aeruginosa to antibiotics • To find the mechanistic basis for antibiotic tolerance upon glutaraldehyde exposure Materials & Methods Four bacterial isolates were exposed to sub-inhibitory glutaraldehyde. Antibiotic tolerance was determined by time-kill assays. Regrowth dynamics (lag times) were determined with ScanLag. E. coli was further investigated, using RNAseq to identify genes and processes involved in antibiotic tolerance. Mutants of candidate genes were screened for their antibiotic tolerance and heterogeneous target gene expression under stressed and unstressed conditions. Results Short-term exposure to sub-inhibitory levels of glutaraldehyde induced tolerance to high doses of bactericidal antibiotics. Tolerance to antibiotics was associated with highly heterogeneous regrowth dynamics and global transcriptome remodeling. Differentially expressed genes represented diverse biological functions and cellular components, including antibiotic efflux, metabolic processes, and the cell envelope. The heterogeneous regrowth dynamics and the diversity of the differentially expressed genes are likely related to the unspecific mode-of-action of glutaraldehyde. Among the many differentially expressed genes, several genes were identified that were not previously associated with antibiotic tolerance or persistence, which, when overexpressed alone, increased antibiotic tolerance. Conclusion Our results highlight how the big advantage of a disinfectant, its unspecific mode-of-action, can induce transient tolerance to antibiotics in bacteria. These findings have implications for 1.) settings where disinfectants and antibiotics are used in proximity, such as hospitals and animal husbandry, and 2.) for the selection dynamics of tolerant bacteria in fluctuating environments because of the trade-off that arises from overcoming the lag phase as fast as possible and maintaining antibiotic tolerance. T2 - VAAM Jahrestagung 2023 CY - Göttingen, Germany DA - 10.09.2023 KW - Glutaraldehyde KW - Disinfectants KW - Biocides KW - Antibiotics KW - Bacteria PY - 2023 AN - OPUS4-58439 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas A1 - Schreiber, Frank T1 - Heterogeneous tolerance to biocides and its consequences for the evolution of antimicrobial resistance N2 - The exposure to antimicrobial substances drives the evolution of antimicrobial resistance (AMR). Biocides are antimicrobials used as disinfectants, antiseptics and preservatives. They find application on a large scale in the industrial and medical sector, but also in private households. In terms of mass, the worldwide use of biocides exceeds that of antibiotics. Thus, despite their important role in preventing the spread of pathogens, due to their ubiquity, biocides are suspected to be drivers of the antimicrobial resistance crisis. In our work we try to understand how biocides contribute to the emergence of AMR, what the underlying adaptation principles and mechanisms are and how they compare to those found for antibiotics. Here, I present results which demonstrate that phenotypic heterogeneity in E. coli, namely the formation of tolerant persister cells, can enable the survival of disinfection and consequentially facilitate the evolution of AMR. Using experimental evolution that selects for tolerance, we find that mutations in lipid A biosynthesis arise following periodic treatment with benzalkonium chloride (BAC), a widely used disinfectant. BAC tolerance is associated with additional, diverse mutations as well as changes in the susceptibility to antibiotics from different classes and changes in motility and biofilm formation, suggesting extensive regulatory re-wiring in the evolved clones. Remarkably, we find that fitness costs (growth rate reduction) incurred by BAC tolerance are alleviated in the presence of antibiotics. These findings demonstrate the complexity underlying the adaptation to antimicrobials and highlight the links between persistence to disinfectants and resistance evolution to antimicrobials. T2 - 4th VAAM discussion meeting 'Microbial Cell Biology' CY - Berlin, Germany DA - 09.10.2022 KW - Persistence KW - Biocides KW - Evolution KW - Disinfection KW - Biocide tolerance KW - Heterogeneity PY - 2022 AN - OPUS4-55958 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas A1 - Kanaris, Orestis A1 - Schmidt, Selina A1 - Schreiber, Frank T1 - Persistence against benzalkonium chloride promotes rapid evolution of tolerance under periodic disinfection N2 - The exposure to antimicrobial substances drives the evolution of antimicrobial resistance (AMR). Biocides are antimicrobials used as disinfectants, antiseptics and preservatives. They find application on a large scale in the industrial and medical sector, but also in private households. In terms of mass, the worldwide use of biocides exceeds that of antibiotics. Thus, despite their important role in preventing the spread of pathogens, due to their ubiquity, biocides are suspected to be drivers of the antimicrobial resistance crisis. In our work we try to understand how biocides contribute to the emergence of AMR, what the underlying adaptation principles and mechanisms are and how they compare to those found for antibiotics. Here, I present results which demonstrate that phenotypic heterogeneity in E. coli, namely the formation of tolerant persister cells, can enable the survival of disinfection and consequentially facilitate the evolution of AMR. Using experimental evolution that selects for tolerance, we find that mutations in lipid A biosynthesis arise following periodic treatment with benzalkonium chloride (BAC), a widely used disinfectant. BAC tolerance is associated with additional, diverse mutations as well as changes in the susceptibility to antibiotics from different classes and changes in motility and biofilm formation, suggesting extensive regulatory re-wiring in the evolved clones. Remarkably, we find that fitness costs (growth rate reduction) incurred by BAC tolerance are alleviated in the presence of antibiotics. These findings demonstrate the complexity underlying the adaptation to antimicrobials and highlight the links between persistence to disinfectants and resistance evolution to antimicrobials. T2 - Bacterial Networks (BacNet22) CY - Sant Feliu de Guixols, Spanien DA - 04.09.2022 KW - Persistence KW - Biocides KW - evolution KW - disinfection KW - biocide tolerance PY - 2022 AN - OPUS4-55713 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas A1 - Schreiber, Frank A1 - Kanaris, Orestis T1 - Consequences of BAC tolerance for selection and evolution in the presence of antibiotics N2 - The exposure to antimicrobial substances drives the evolution of antimicrobial resistance. Biocides are antimicrobials used as disinfectants, antiseptics and preservatives. They find application on a large scale in the industrial and medical sector, but also in private households. In terms of mass, the worldwide use of biocides exceeds that of antibiotics. Thus, despite their important role in preventing the spread of pathogens, due to their ubiquity, biocides are suspected to be drivers of the antimicrobial resistance crisis. In our work at BAM we try to understand how biocides contribute to the emergence of AMR, what the underlying adaptation principles and mechanisms are and how they compare to those found for antibiotics. Within our group, I mainly focus on the following two questions: How does phenotypic heterogeneity in bacteria affect the ability to survive treatment with biocides? And what are the consequences of phenotypic heterogeneity for the evolution of resistance to biocides and antibiotics? I will share published and unpublished results which demonstrate that phenotypic heterogeneity can enable the survival of biocide treatment and, through this, facilitate the evolution of AMR. On the other hand, we find that adaptation to a biocide can unexpectedly impair the ability to evolve resistance against an antibiotic. T2 - FEMS summer school for postdocs 2022: Microbial Evolvability Mechanisms: Resistance, Biology, and Strategies to Defeat and Detect CY - Split, Croatia DA - 27.04.2022 KW - Disinfection KW - Biocides KW - Evolution KW - Resistance KW - Biocide tolerance PY - 2022 AN - OPUS4-54846 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas A1 - Schmidt, Selina A1 - Schreiber, Frank T1 - Persistence as a microbial survival strategy against disinfectants N2 - Antimicrobial resistance is a major threat to human health. The prevalence of multi-drug resistant (MDR) bacteria is predicted to increase in the future requiring robust control strategies. One cornerstone to prevent the spread of MDR bacteria in clinical settings is the application of disinfectants to improve hygiene standards. However, bacteria can evolve resistance to disinfectants, which in turn can confer cross-resistance to antibiotics. Additionally, clonal bacterial populations can display phenotypic heterogeneity with respect to the tolerance of antibiotic stress leading to a prolonged survival of a sub-population; this phenomenon is termed persistence. Persistence to antibiotics is an evolvable trait and can serve as a stepping stone for the evolution of genetically encoded resistance. Until now, there is a lack of systematic studies that investigate if bacterial populations establish persister subpopulations that tolerate disinfectant stress longer than the majority of the population. Our results in E. coli indicate that persistence is a bacterial survival strategy against benzalkonium chloride, a widely used disinfectant. In future experiments, we will investigate the evolution of persistence in the face of fluctuating exposure to disinfectants and whether persistence facilitates resistance against disinfectants. Lastly, we will test how tolerance and resistance against disinfectants affects susceptibility against antibiotics. T2 - Bridging Ecology and Molecular Biology: Organismic Responses to Recurring Stress CY - Berlin, Germany DA - 09.04.2018 KW - Bacteria KW - Persistence KW - Resistance KW - Biocides PY - 2018 N1 - Geburtsname von Schmidt, Selina: Broska, S. - Birth name of Schmidt, Selina: Broska, S. AN - OPUS4-44667 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas A1 - Kanaris, Orestis A1 - Schmidt, Selina A1 - Schreiber, Frank T1 - Persistence against benzalkonium chloride promotes rapid evolution of tolerance under periodic disinfection N2 - A presentation given at the VAAM conference 2022, summarizing our findings published in the research paper "Persistence against benzalkonium chloride promotes rapid evolution of tolerance under periodic disinfection" T2 - Annual conference of the association for general and applied microbiology (VAAM) 2022 CY - Düsseldorf, Germany DA - 21.02.2022 KW - Persistence KW - Biocides KW - Evolution KW - Cross-resistance KW - Biocide tolerance KW - Disinfection PY - 2022 AN - OPUS4-54437 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas A1 - Schreiber, Frank T1 - Phenotypic heterogeneity in disinfection: sources and consequences for antimicrobial resistance N2 - A summary of projects here at BAM which investigate the influence of phenotypic heterogeneity on the outcome of disinfection and the influence on antimicrobial resistance. This presentation was given in the Theory Seminar of the Quantitative and Theoretical Biology group of Prof. Oliver Ebenhöh at HHU Düsseldorf T2 - Theory Seminar in the Quantitative and Theoretical Biology group at HHU Düsseldorf CY - Düsseldorf, Germany DA - 24.02.2022 KW - Disinfection KW - Biocides KW - Heterogeneity KW - Resistance PY - 2022 AN - OPUS4-54442 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mirabella, Francesca A1 - Mezera, Marek A1 - Wasmuth, Karsten A1 - Hertwig, Andreas A1 - Richter, Anja A1 - Schwibbert, Karin A1 - Krüger, Jörg A1 - Bonse, Jörn A1 - Hodoroaba, Vasile-Dan T1 - ToF-SIMS as a new tool for nano-scale investigation of ps-laser-generated surface structures on titanium substrates N2 - In recent years, the fabrication of laser-generated surface structures on metals such as titanium surfaces have gained remarkable interests, being technologically relevant for applications in optics, medicine, fluid transport, tribology, and wetting of surfaces. The morphology of these structures, and so their chemistry, is influenced by the different laser processing parameters such as the laser fluence, wavelength, pulse repetition rate, laser light polarization type and direction, angle of incidence, and the effective number of laser pulses per beam spot area. However, the characterization of the different surface structures can be difficult because of constraints regarding the analytical information from both depth and the topographic artifacts which may limit the lateral and depth resolution of elemental distributions as well as their proper quantification. A promising technique to investigate these structures even at the nano-scale is Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), a very surface sensitive technique that at the same time allows to perform depth-profiling, imaging and 3D-reconstruction of selected ion-sputter fragment distributions on the surface. In this study we combine chemical analyses such as Energy Dispersive X-ray spectroscopy (EDX) and high-resolution scanning electron microscopy (SEM) analyses with ToF-SIMS to fully characterize the evolution of various types of laser-generated micro- and nanostructures formed on Ti and Ti alloys at different laser fluence levels, effective number of pulses and at different pulse repetition rates (1 – 400 kHz), following irradiation by near-infrared ultrashort laser pulses (925 fs, 1030 nm) in air environment or under argon gas flow. We show how this combined surface analytical approach allows to evaluate alteration in the surface chemistry of the laser-generated surface structures depending on the laser processing parameters and the ambient environment. T2 - European Materials Research Society (EMRS) Fall Meeting 2021 CY - Online meeting DA - 20.09.2021 KW - ToF SIMS KW - Nano characterization PY - 2021 AN - OPUS4-53366 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mezera, Marek A1 - Richter, Anja A1 - Krüger, Jörg A1 - Bonse, Jörn A1 - Schwibbert, Karin T1 - Bacterial adhesion on femtosecond laser-induced periodic surface structures N2 - Biofilm formation in industrial or medical settings is usually unwanted and leads to serious health problems and high costs. Inhibition of initial bacterial adhesion prevents biofilm formation and is, therefore, a major mechanism of antimicrobial action of surfaces. Surface topography largely influences the interaction between bacteria and surfaces which makes topography an ideal base for antifouling strategies and eco-friendly alternatives to chemical surface modifications. Femtosecond laser-processing was used to fabricate sub-micrometric surface structures on silicon and stainless steel for the development of antifouling topographies on technical materials. T2 - Future Tech Week 2020 CY - Online meeting DA - 21.09.2020 KW - Laser-induced periodic surface structures (LIPSS) KW - Bacterial adhesion KW - Biofilm growth KW - Structural color KW - Femtosecond laser processing PY - 2020 UR - http://futuretechweek.fetfx.eu/wp-content/uploads/gravity_forms/2-5432af7ecff9e0243d7383ab3f931ed3/2020/09/BioCombs4Nanofibers_Poster-for-Future_Tech_Week_2020_08-09-2020_with_Reprint-permission_for_upload.pdf AN - OPUS4-51233 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mezera, Marek A1 - Mirabella, Francesca A1 - Wasmuth, Karsten A1 - Richter, Anja A1 - Schwibbert, Karin A1 - Bennet, Francesca A1 - Krüger, Jörg A1 - Hodoroaba, Vasile-Dan A1 - Bonse, Jörn T1 - Influence of the pulse repetition rate on the chemical and morphological properties of laser generated surface structures N2 - Inter-pulse accumulation of heat could affect the chemical and morphological properties of the laser processed material surface. Hence, the laser pulse repetition rate may restrict the processing parameters for specific laser-induced surface structures. In this study, the evolution of various types of laser-induced micro- and nanostructures at various laser fluence levels, effective number of pulses and at different pulse repetition rates (1 – 400 kHz) are studied for common metals/alloys (e.g. steel or titanium alloy) irradiated by near-infrared ultrashort laser pulses (925 fs, 1030 nm) in air environment. The processed surfaces were characterized by optical and scanning electron microscopy (OM, SEM), energy dispersive X-ray spectroscopy (EDX) as well as time of flight secondary ion mass spectrometry (TOF-SIMS). The results show that not only the surface morphology could change at different laser pulse repetition rates and comparable laser fluence levels and effective number of pulses, but also the surface chemistry is altered. Consequences for medical applications are outlined. T2 - European Materials Research Society Spring 2021 Meeting CY - Online meeting DA - 31.05.2021 KW - Laser-induced pariodic surface structures KW - LIPSS PY - 2021 AN - OPUS4-52778 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - McMahon, Dino Peter A1 - Esparza, M. A1 - Davis, H. A1 - Margy, A. T1 - Infection stage and pathogen life cycle determine collective termite behaviour N2 - Social insects nesting in soil environments are in constant contact with entomopathogens and have evolved disease resistance mechanisms within a colony to prevent the occurrence and spread of infectious diseases. Among these mechanisms: mutual grooming reduces the cuticular load of pathogens, and burial of cadavers and cannibalism can prevent pathogens from replicating within the group. We explored how the rate and type of collective behavioural response is determined by stepwise infection dynamics operating at the level of the individual. Specifically, we infected the eastern subterranean termite Reticulitermes flavipes with different types of infectious particle and infection route of the entomopathogenic fungus Metarhizium anisopliae and recorded behavioural responses of nestmates to individuals at different times during the progression of infections. As expected, termites groomed conidia-exposed individuals significantly more than controls. Interestingly, grooming was significantly elevated after fungal germination than before, suggesting that pathogen growth cues act as strong stimulators of allogrooming. Conidia-exposed termites were cannibalized, but only after they became visibly ill. By contrast, termites did not groom blastospore-injected individuals more than controls at any time-point following infection. Instead, we found that blastospore-injected individuals were continually cannibalized at a low-level following injection with either viable or heat-killed blastospores, with a marked increase in cannibalism after termites injected with viable blastospores became visibly ill and were close to death. Together, these findings point to the importance of host condition as a cue for social hygienic behavior, and that the host itself appears to emit essential sickness cues that act as targets for its own sacrifice. This demonstrates that termites have independently evolved to both identify and destructively respond to sickness. T2 - VI Central European Meeting of the IUSSI 2019 CY - Wien, Austria DA - 19.03.2019 KW - Termite KW - Evolution KW - Social immunity PY - 2019 AN - OPUS4-49643 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - McMahon, Dino Peter T1 - The evolution of termite immunity N2 - The termites are a derived eusocial lineage of otherwise non-social cockroaches. Understanding the proximal and ultimate drivers of this major evolutionary transition represents an important goal in biology. One outstanding question concerns the evolution of termite immunity, which is thought to have undergone broad-sweeping adaptations in order to enhance group-level immune protection. To understand the evolutionary origins of termite immunity, we conducted qualitative and quantitative transcriptome analyses along a gradient of sociality. Firstly, we aimed to identify large-scale genetic shifts in immune traits linked to eusociality by comparing immune gene repertoires in solitary and subsocial cockroaches and across a range of eusocial termite lineages. Secondly, we compared the responses of a solitary cockroach, a subsocial wood-roach and different castes of a lower termite species to a non-specific immune challenge, in order to understand how sociality may have influenced the evolution of immune gene regulation. Firstly, we found that termites have a broadly representative repertoire of canonical immune genes as compared to gregarious cockroaches and subsocial wood-roaches. Secondly, with respect to immune challenge, the solitary cockroach and the subsocial wood-roach displayed a similarly comprehensive induced response, while the termite response was considerably dampened by comparison and strongly influenced by caste; with reproductives displaying a generally higher constitutive level of immune-gene expression compared to sterile castes. In summary we did not find termite eusociality to be associated with significant changes in immune gene diversity, but rather to be linked with significant modifications to the regulation of immunity following the origin of division of labour. T2 - Institute for Evolution and Biodiversity Lecture Series, Universität Münster CY - Münster, Germany DA - 20.02.2019 KW - Immunity KW - Evolution KW - Ecology KW - Termite KW - Molecular PY - 2019 AN - OPUS4-49644 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - McMahon, Dino Peter T1 - G-BOP kick-off meeting proposal ideas Ecology and evolution of termite immunity N2 - Results suggest a reduction in immune gene repertoires in termites and possible complementary expression between termite castes. With comparative genomics we will investigate the evolution of gene families related to immunity, try to understand where reductions and expansions take place and relate these changes to shifts in sociality and ecology. The role of TEs in expansions and contractions of immune gene families will be investigated. For these analyses, we propose to generate high quality, highly contiguous genomes of species from different levels of sociality, covering all major termite families. With comparative transcriptomics we will investigate the expression of immune genes in different castes. Via network analyses we will identify pathways indicated in differential immunity between castes and between species of different sociality levels. We will investigate how these pathways have been rewired along the transitions to higher levels of sociality and how, intra-specifically, they change between castes. T2 - Rundgespräch zur Vorbereitung eines SPP G-BOP - Genomic Basis Of Phenotypic Innovations in Insect Evolution CY - Zoologisches Forschungsmuseum, Bonn, Germany DA - 16.05.2019 KW - Bioinformatics KW - Evolution KW - Termites PY - 2019 AN - OPUS4-49645 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - McMahon, Dino Peter T1 - The evolution of termite immunity N2 - A broad suite of immune adaptations have evolved in social insects which hold close parallels with the immune systems of multicellular individuals. However, comparatively little is known about the evolutionary origins of immunity in social insects. We tackle this by identifying immune genes from 18 cockroach and termite species, spanning a gradient of social lifestyles. Termites have undergone contractions of major immune gene families during the early origin of the group, particularly in antimicrobial effector and receptor proteins, followed by later re-expansions in some lineages. In a comparative gene expression analysis, we find that reproductive individuals of a termite invest more in innate immune regulation than other castes. When colonies encounter immune-challenged nestmates, gene expression responses are weak in reproductives but this pattern is reversed when colony members are immune-challenged individually, with reproductives eliciting a greater response to treatment than other castes. Finally, responses to immune challenge were more comprehensive in both subsocial and solitary cockroaches compared to termites, indicating a reduced overall ability to respond to infection in termites. Our study indicates that the emergence of termite sociality was associated with the evolution of a tapered yet caste-adapted immune system. T2 - 112th Annual Meeting of the German Zoological Society CY - Jena, Germany DA - 10.09.2019 KW - Social KW - E$volution KW - Termite KW - Immunity PY - 2019 AN - OPUS4-49646 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -