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 - 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 - 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 - Leube, Peter A1 - Vogel, Christian A1 - Simon, Franz-Georg T1 - Quantification of ultrashort per- and polyfluoroalkyl substances (PFAS) in water samples via headspace gas chromatography-mass spectrometry (GC-MS) - a method development N2 - Per- and polyfluoroalkyl substances (PFAS) were classified as a group of highly concerning chemicals over the last decades. Because of the high persistence of PFAS, their previous use led to contamination of the environment and human population. Due to ongoing use and incomplete remediation or destruction methods, the PFAS background in the environment is growing continuously. The presence of ultrashort PFAS (with ≤3 carbon atoms) in the environment is often overlooked despite their contributions to PFAS levels. These compounds may directly contaminate the environment and arise from degradation of polyfluorinated compounds as well as incomplete PFAS destruction in certain industrial processes. Nonetheless, few approaches for targeted analysis of ultrashort PFASs have been developed, except for trifluoroacetic acid (TFA). Beside liquid (LC-MS/MS), supercritical fluid (SFC-MS/MS), and ion chromatography (IC-MS)-based systems, gas chromatography coupled with mass spectrometry (GC-MS) is a promising method for detection and quantification of ultrashort PFAS. The goal of this study was to develop a simple headspace GC-MS method for the quantification of ultrashort perfluorocarboxylic acids (PFCAs) and polyfluorinated alcohols (PFOHs) in water samples. In contrast to PFOHs, functionalization of PFCAs was required for quantification. This was done by esterification with methanol at 80 °C, which can be carried out directly in the headspace GC-MS system. Moreover, several parameters were optimized to achieve a low limit of quantification (LOQ) for the analytes used: i) The ratio of the aqueous solution, methanol, and available gas phase within the analysis vessel, ii) the concentration of additional acid in esterification mixtures of PFCAs, iii) shaking frequency and iv) shaking time before analysis. After optimizing the procedure, we were able to quantify ultrashort PFCAs and PFOHs. Thus, our developed headspace GC-MS method has the potential to be used as an alternative target analysis for ultrashort-chain PFCAs and PFOHs in various water samples (groundwater, wastewater). T2 - SETAC Europe 34th Annual Meeting CY - Seville, Spain DA - 05.05.2024 KW - Ultrashort PFAS KW - Headspace GC-MS KW - Perfluorocarboxylic acid (PFCA) KW - Polyfluorinated alcohol (PFOH) PY - 2024 AN - OPUS4-60042 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vogel, Christian A1 - Roesch, Philipp A1 - Wittwer, Philipp A1 - Kalbe, Ute A1 - Simon, Franz-Georg T1 - Diffusive Gradients in Thin-films (DGT) technique as screening tool for per- and polyfluoroalkyl substances (PFAS) contamination in wastewater-based fertilizers N2 - Per- and polyfluoroalkyl substances (PFAS) are a large group of organofluorine surfactants used in the formulations of thousands of consumer goods, including aqueous film-forming foams (AFFF) used to suppress aviation fires in training scenarios, non-stick cookware, fast-food wrappers, water-repellent fabrics, medical equipment, and plastic and leather products. As a result of the perpetual use of PFAS containing products, effluents and sewage sludge from wastewater treatment plants (WWTPs) have been observed to be an important pathway for PFAS into the environment. In Germany, phosphorus and other nutrients from sewage sludge and wastewater should be recycled in WWTPs of cities with a large population. However, it is not clear if PFAS contamination from wastewater and sewage sludge end up in novel wastewater-based fertilizers. Normally, PFAS are analyzed using PFAS protocols typically with time-consuming extraction steps and LC-MS-MS quantification. However, for screening of PFAS contaminations in sewage sludge or wastewater-based fertilizers also passive sampler based on the Diffusive Gradients in Thin-films (DGT) technique can be used for the PFAS extraction. Afterwards, combustion ion chromatography (CIC) can be applied to analyse the “total” amount of PFAS on the passive sampler. Here, we show results from the DGT method in comparison to those of the extractable organic fluorine (EOF) method for a variety of wastewater-based fertilizers. Additionally, we analysed the adsorption of PFAS on the weak anion exchanger (WAX) based DGT passive sampler binding layer by infrared and fluorine K-edge X-ray adsorption near-edge structure (XANES) spectroscopy. T2 - SETAC Europe 2022 CY - Copenhagen, Denmark DA - 15.05.2022 KW - Passive sampling KW - Per- and Polyfluoroalkyl substances (PFAS) KW - Sewage sludge KW - Wastewater PY - 2022 AN - OPUS4-54883 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Simon, Franz-Georg A1 - Chubarenko, B. A1 - Purina, I. T1 - Approach for analysis of environmental impact of geosynthetics in aquatic systems by example of the Baltic Sea N2 - Whereas the behavior of geosynthetics in landfill engineering is well studied and documented since decades, little is known on application in applications such as coastal protection or ballast layers for wind energy plants. However, due to the rapid expansion of offshore wind energy, rising water levels and more extreme weather conditions as a result of climate change more and more hydraulic engineering projects will be realized in the future. Construction with geosynthetics has various advantages, but it has to be ensured that there is no negative environmental impact from the application of geosynthetics in hydraulic engineering. It is expected that any effect will be visible only on the long-term. Therefore, accelerated testing is needed to derive requirements for geosynthetics in hydraulic engineering. T2 - 7th IEEE/OES Baltic Symposium, Clean and Safe Baltic Sea and Energy Security for the Baltic countries CY - Klaipeda, Lithuania DA - 12.06.2018 KW - Geosynthetics KW - Artificial ageing KW - Micro plastic PY - 2018 AN - OPUS4-45206 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon A1 - Maierhofer, Christiane A1 - Hilgenberg, Kai A1 - Mohr, Gunther A1 - Gumenyuk, Andrey A1 - Straße, Anne A1 - Pittner, Andreas A1 - Günster, Jens A1 - Gornushkin, Igor B. A1 - Pelkner, Matthias A1 - Ehlers, Henrik A1 - Heckel, Thomas A1 - Zscherpel, Uwe A1 - Seeger, Stefan A1 - Bruno, Giovanni T1 - ProMoAM - Verfahrensentwicklung für das Prozessmonitoring in der additiven Fertigung N2 - Verfahren zum in-situ Monitoring der Prozess- und Bauteilparameter sollen Fehlstellen und Inhomogenitäten bereits während der Fertigung nachweisen und zukünftig auch die Regelung der Prozessparameter ermöglichen. T2 - Challenges in Additive Manufacturing: Innovative Materials and Quality Control, Berlin Partner Workshop CY - Berlin, Germany DA - 12.09.2018 KW - Additive Fertigung KW - Prozessmonitoring KW - ProMoAM PY - 2018 AN - OPUS4-46300 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Roesch, Philipp A1 - Wittwer, Philipp A1 - Vogel, Christian A1 - Simon, Franz-Georg T1 - Investigation of PFAS Contaminated Solid Matrices by Combustion Ion Chromatography (CIC) - Development of EOF and AOF as Sum Parameters in Environmental Analysis N2 - Per- and polyfluoralkyl surfactants (PFAS) are industrially produced surface chemicals used in daily applications that have gained public and political attention due their unnaturally high appearance in drinking water, nourishments and soils.[1] Their chemical structures exhibit both lipophilic and hydrophilic properties, leading to a highly inert and persistent character.[2] Various PFAS have shown to be bioaccumulative in plants and animals, and some have been characterized as highly toxic when ingested.[3] When exposed to the environment, PFAS slowly get mobilized by natural water resources, leading to contamination of large areas of soil and natural water sources.[4] While PFAS contamination of drinking water has been investigated intensively, perfluoralkyl contamination of soils has been rarely examined as of yet. At the same time, an increasing amount of PFAS contamination sites are being discovered worldwide, calling for a sophisticated strategy towards analytical characterization.[5] Since the number of known PFAS already exceeds 4700, the established sum parameters like extractable organic fluorine (EOF) and adsorbable organic fluorine (AOF) are key elements to fully survey the impact of exposure.[6] Simultaneously, innovative soil remediation strategies are required to contain environmental destruction and to minimize further spreading of contaminants.[7] Addressing these challenges requires suitable analytical devices that are capable of mobilizing PFAS in the solid as well as in the liquid phase. The use of combustion ion chromatography (CIC) enables analysis of both immobile and volatile PFAS and allows the detection of both total fluorine (TF) and EOF or AOF of a given soil or aqueous sample. Based on preliminary results, the clean-up of a PFAS contaminated matrix is monitored via EOF detection over time. Additionally, we tested the effectiveness of urea (CH₄N₂O) as fluoride scavenger with the aim to improve the separation of inorganic and organic fluorine and therefore, to improve AOF accuracy. The presented findings can be contributive with regard to future AOF/EOF sum parameter development and application. T2 - Eurosoil 2021 CY - Online meeting DA - 23.08.2021 KW - PFAS KW - Sum parameter analyis KW - Combustion ion chromatography PY - 2021 AN - OPUS4-53195 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vogel, Christian A1 - Kalbe, Ute A1 - Simon, Franz-Georg T1 - Leaching behavior of Antimony in MSWI bottom ash N2 - Bottom ash (BA) from municipal solid waste incineration (MSWI) contains harmful substances such as heavy metals, chloride and sulfate which are mobilized in contact with water. Standardized leaching tests are used to measure the extent of mobilization. It is known that fresh bottom ash displays elevated concentrations of various heavy metals such as lead or zinc due to the formation of hydroxo complexes as a result of high pH values of 12 and above. Storage of BA is accompanied by ageing processes, mainly the reaction of CaO and Ca(OH)2 with CO2 leading to lower pH values in contact with water around 11. Usually heavy metals concentrations are minimum at these conditions. Knowledge of the long-term leaching behavior of potentially harmful substances is crucial for the assessment of the environmental compatibility of reusing municipal solid-waste incineration bottom ash (MSWI BA) in construction, i.e., as a road base layer. BA fractions obtained from wet-processing aiming at the improvement of environmental quality were used to investigate the mobility of relevant substances. Eluates from laboratory-scaled leaching procedures (column percolation and lysimeters) were analyzed to learn about the long-term release of substances. Unsaturated conditions and artificial rainwater were used in the lysimeter tests to simulate field conditions. In addition, batch test eluates were generated at usual liquid-to-solid ratios (L/S) for compliance testing purposes. A variety of cations and anions was measured in the eluates. The wet treatment reduces the leaching of chloride and particularly sulfate by more than 60%. The release of typical contaminants for the treated MSWI BA such as the heavy metals Cu and Cr was well below 1% in the conducted leaching tests. An increase in the Sb concentration was observed in the lysimeter experiments starting at L/S 0.75 L/kg and in the column experiment at L/S 4 L/kg is assumed to be related to decreasing concentrations of Ca and thus to the dissolution of sparingly soluble calcium antimonate. The same leaching mechanism applies with V, but the concentration levels observed are less critical regarding relevant limit values. However, on the long term the behavior of Sb could be problematic for the application of MSWI BA as secondary building material. T2 - MINEA Final Conference CY - Bologna, Italy DA - 20.02.2020 KW - Antimony KW - Bottom ash KW - Leaching KW - Solubility PY - 2020 AN - OPUS4-50450 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gehrenkemper, Lennart A1 - Simon, Fabian A1 - Roesch, Philipp A1 - Fischer, Emily A1 - von der Au, Marcus A1 - Pfeifer, Jens A1 - Cossmer, Antje A1 - Wittwer, Philipp A1 - Vogel, Christian A1 - Simon, Franz-Georg A1 - Meermann, Björn T1 - Organically bound fluorine in river water - A methode comparison of CIC and HR-CS-GFMAS N2 - Abstract: Since it is unknown for many applications, which PFASs are used and how they enter the environment, target analysis-based methods reach their limits. The two most frequently used sum parameters are the adsorbable organically bound fluorine (AOF) and the extractable organically bound fluorine (EOF). Both can be quantified using either combustion ion chromatography (CIC) or high resolution-continuum source-graphite furnace molecular absorption spectrometry (HR-CS-GFMAS). Here we provide an insight on the advantageous and disadvantageous of both sum parameters and both detection methods. Our study is based on the analysis of surface water samples. Next to total fluorine (TF) analysis, AOF and EOF were determined as well as CIC and HR-CS-GFMAS are compared and results are comparatively discussed. Fluorine mass balancing revealed that, the AOF/TF proportion was higher than the EOF/TF proportion. The AOF made up 0.14–0.81% of TF and the EOF 0.04–0.28% of TF. Although, organically bound fluorine represents only a small portion of TF, PFASs are of worldwide concern, because of their extreme persistence and their bioaccumulation potential. The EOF-HR-CS-GFMAS method turned out to be more precise and sensitive than the AOF-CIC method and is a promising tool for future monitoring studies/routine analysis of PFASs in the environment. T2 - SALSA Make and Measure 2020: Advanced Characterization of Materials CY - Online meeting DA - 15.10.2020 KW - High resolution-continuum source-graphite furnace molecular absorption spectrometry (HR-CS-GFMAS) KW - Combustion ion chromatography (CIC) KW - Per- and polyfluorinated alkyl substances (PFASs) KW - Adsorbable organically bound fluorine (AOF) KW - Extractable organically bound fluorine (EOF) KW - Surfacewaters PY - 2020 AN - OPUS4-52451 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -