Refine
Year of publication
Document Type
Way of publication
- Open Access (4)
Keywords
- CRISPR/Cas9 (2)
- Pan troglodytes ellioti (2)
- multiplexing (2)
- 3D Printing (1)
- ANCA (1)
- Bushmeat hunting (1)
- Cell Biology (1)
- Core areas (1)
- CytoBead technology (1)
- DNA damage response (DDR) (1)
Institute
- FG Multiparameterdiagnostik (122)
- FG Biochemie (3)
- FG Ökologie (3)
- FG Zellbiologie (2)
- FG Anorganische Chemie (1)
- FG Molekularbiologie (1)
- FG Molekulare Zellbiologie (1)
- FG Nanobiotechnologie (1)
BTU
Escherichia coli intestinal infection pathotypes are characterized by distinct adhesion patterns, including the recently described clumpy adhesion phenotype. Here, we identify and characterize the genetic factors contributing to the clumpy adhesion of E. coli strain 4972. In this strain, the transcriptome and proteome of adhered bacteria were found to be distinct from planktonic bacteria in the supernatant. A total of 622 genes in the transcriptome were differentially expressed in bacteria present in clumps relative to the planktonic bacteria. Seven genes targeted for disruption had variable distribution in different pathotypes and nonpathogenic E. coli, with the pilV and spnT genes being the least frequent or absent from most groups. Deletion (Δ) of five differentially expressed genes, flgH, ffp, pilV, spnT, and yggT, affected motility, adhesion, or antibiotic stress. ΔflgH exhibited 80% decrease and ΔyggT depicted 184% increase in adhesion, and upon complementation, adhesion was significantly reduced to 13%. ΔflgH lost motility and was regenerated when complemented, whereas Δffp had significantly increased motility, and reintroduction of the same gene reduced it to the wild-type level. The clumps produced by Δffp and ΔspnT were more resistant and protected the bacteria, with ΔspnT showing the best clump formation in terms of ampicillin stress protection. ΔyggT had the lowest tolerance to gentamicin, where the antibiotic stress completely eliminated the bacteria. Overall, we were able to investigate the influence of clump formation on cell surface adhesion and antimicrobial tolerance, with the contribution of several factors crucial to clump formation on susceptibility to the selected antibiotics.
Intestinal colonization is influenced by the ability of the bacterium to inhabit a niche, which is based on the expression of colonization factors. Escherichia coli carries a broad range of virulence-associated genes (VAGs) which contribute to intestinal (inVAGs) and extraintestinal (exVAGs) infection. Moreover, initial evidence indicates that inVAGs and exVAGs support intestinal colonization. We developed new screening tools to genotypically and phenotypically characterize E. coli isolates originating in humans, domestic pigs, and 17 wild mammal and avian species. We analyzed 317 isolates for the occurrence of 44 VAGs using a novel multiplex PCR microbead assay (MPMA) and for adhesion to four epithelial cell lines using a new adhesion assay. We correlated data for the definition of new adhesion genes. inVAGs were identified only sporadically, particularly in roe deer (Capreolus capreolus) and the European hedgehog ( Erinaceus europaeus). The prevalence of exVAGs depended on isolation from a specific host. Human uropathogenic E. coli isolates carried exVAGs with the highest prevalence, followed by badger (Meles meles) and roe deer isolates. Adhesion was found to be very diverse. Adhesion was specific to cells, host, and tissue, though it was also unspecific. Occurrence of the following VAGs was associated with a higher rate of adhesion to one or more cell lines: afa-dra, daaD, tsh, vat, ibeA, fyuA, mat, sfa-foc, malX, pic, irp2, and papC. In summary, we established new screening methods which enabled us to characterize large numbers of E. coli isolates. We defined reservoirs for potential pathogenic E. coli. We also identified a very broad range of colonization strategies and defined potential new adhesion genes.
We established an automated screening method to characterize adhesion of Escherichia coli to intestinal porcine epithelial cells (IPEC-J2) and their probiotic activity against infection by enteropathogenic E. coli (EPEC). 104 intestinal E. coli isolates from domestic pigs were tested by PCR for the occurrence of virulence-associated genes, genes coding for resistances to antimicrobial agents and metals, and for phylogenetic origin by PCR. Adhesion rates and probiotic activity were examined for correlation with the presence of these genes. Finally, data were compared with those from 93 E. coli isolates from wild boars.
Isolates from domestic pigs carried a broad variety of all tested genes and showed great diversity in gene patterns. Adhesions varied with a maximum of 18.3 or 24.2 mean bacteria adherence per epithelial cell after 2 or 6 hours respectively. Most isolates from domestic pigs and wild boars showed low adherence, with no correlation between adhesion/probiotic activity and E. coli genes or gene clusters. The gene sfa/foc, encoding for a subunit of F1C fimbriae did show a positive correlative association with adherence and probiotic activity; however E. coli isolates from wild boars with the sfa/foc gene showed less adhesion and probiotic activity than E. coli with the sfa/foc gene isolated from domestic pigs after 6 hour incubation.
In conclusion, screening porcine E. coli for virulence associated genes genes, adhesion to intestinal epithelial cells, and probiotic activity revealed a single important adhesion factor, several probiotic candidates, and showed important differences between E. coli of domestic pigs and wild boars.
Open source bioimage informatic tools for the analysis of DNA damage and associated biomarkers
(2019)
Development of a Method for Multiplex Real-Time Analysis of Enzymatic Activity on a Microbead-Chip
(2013)
A Multiparametic Fluorescence Assay for Screening Aptamer-Protein Interactions Based on Microbeads
(2022)
The Novel Type 1 Fimbriae FimH Receptor Calreticulin Plays a Role in Salmonella Host Specificity
(2017)
The role of AJB35136 and fdtA genes in biofilm formation by avian pathogenic Escherichia coli
(2023)
Serological diagnosis and prognosis of severe acute pancreatitis by analysis of serum glycoprotein 2
(2017)
Chimpanzees feed on driver ants (Dorylus sp.) using different tools and predation techniques that vary among populations and can be affected by availability of ant species as well as ecological and social-learning factors. At the Kom-Wum Forest Reserve (KWFR) in Cameroon, we investigated tool use behavior in Nigerian-Cameroon chimpanzees (Pan troglodytes ellioti), examining the characteristics of tools used in driver ant predation, looking for possible seasonal patterns and comparing our results to those from other study sites. We recovered 83 tools along line transects and recces (reconnaissance) during two seasons. We found that chimpanzees used tools with blunting and dirty ends (possible digging and probing tools) and tools without (dipping tools), in driver ant predation. Tools with dirty ends tended to be thicker (N = 52), and thinner tools were less likely to have dirt (N = 31). Tools recovered in the wet season (N = 62), were significantly shorter and thicker than those recovered in the dry season (N = 21). Furthermore, driver ant tools recovered at KWFR are on average the longest yet recorded insect dipping tools for chimpanzees comparable to those used in North Uele. We found no evidence of nut-cracking, tool use for honey bee nor termite consumption and did not observe the potential prey remains in chimpanzee faeces despite their presence in the reserve. Our results suggest that seasonality significantly contributes to a divergence in the form of tools selected for driver ant predation.
Great apes lose suitable habitats required for their reproduction and survival due to human activities across their distribution range in Africa. Little is known about habitat suitability of the Nigeria–Cameroon chimpanzee [Pan troglodytes ellioti (Matschie, 1914)], particularly for populations inhabiting forest reserves in North-West Cameroon. To address this knowledge gap, we employed a common species distribution model (MaxEnt) to map and predict suitable habitats for the Nigeria–Cameroon chimpanzee in Kom-Wum Forest Reserve, North-West Cameroon, based on environmental factors that potentially affect habitat suitability. We related these environmental factors to a dataset of chimpanzee occurrence points recorded during line transect and reconnaissance (recce) surveys in the forest reserve and surrounding forests. Up to 91% of the study area is unsuitable for chimpanzees. Suitable habitats only represented 9% of the study area, with a high proportion of highly suitable habitats located outside the forest reserve. Elevation, secondary forests density, distance to villages and primary forests density were the most important predictors of habitat suitability for the Nigeria–Cameroon chimpanzee. The probability of chimpanzee occurrence increased with elevation, secondary forest density and distance from villages and roads. Our study provides evidence that suitable chimpanzee habitat in the reserve is degraded, suggesting that efforts to maintain protected areas are insufficient. The reserve management plan needs to be improved to conserve the remaining suitable habitat and to avoid local extinction of this endangered subspecies.
High Prevalence of CTX-M-15-Type ESBL-Producing E. coli from Migratory Avian Species in Pakistan
(2017)
Background: The 3D printing is relevant as a manufacturing technology of functional models for forensic, pharmaceutical and bioanalytical applications such as drug delivery systems, sample preparation and point-of-care tests.
Objective: Melting behavior and autofluorescence of materials are decisive for optimal printing and applicability of the product which are influenced by varying unknown additives.
Methods: We have produced devices for bioanalytical applications from commercially available thermoplastic polymers using a melt-layer process. We characterized them by differential scanning calorimetry, fluorescence spectroscopy and functional assays (DNA capture assay, model for cell adhesion, bacterial adhesion and biofilm formation test).
Results: From 14 tested colored, transparent and black materials we found only deep black acrylonitrile-butadiene-styrene (ABS) and some black polylactic acid (PLA) useable for fluorescence-based assays, with low autofluorescence only in the short-wave range of 300-400 nm. PLA was suitable for standard bioanalytical purposes due to a glass transition temperature of approximately 60°C, resistance to common laboratory chemicals and easy print processing. For temperature-critical methods, such as hybridization reactions up to 90°C, ABS was better suited.
Conclusions: Autofluorescence was not a disadvantage per se but can also be used as a reference signal in assays. The rapid development of individual protocols for sample processing and analysis required the availability of a material with consistent quality over time. For fluorescence-based assays, the use of commercial standard materials did not seem to meet this requirement.
Abstract
BACKGROUND:
Different strategies of colonization or infection by E. coli result in formation of certain adhesion patterns which help also in classifying intestinal E. coli into pathotypes. Little is known about adhesion patterns and host- and tissue adaption of commensal E. coli and about E. coli originating in clinically healthy hosts carrying pathotype-specific virulence-associated genes.
FINDINGS:
Adhesion pattern of E. coli (n = 282) from humans and from 18 animal species were verified on intestinal human Caco-2 and porcine IPEC-J2 cells and, furthermore, for comparison on human urinary bladder 5637, porcine kidney PK-15 epithelial and HEp-2 cells. The analysis was carried out on 150,000 images of adhesion assays.Adhesion patterns were very diverse; 88 isolates were completely non-adherent, whereas 194 adhered to at least one cell line with the dominant adhesion patterns "diffusely distributed" and "microcolony formation". Adhesion patterns "chains" and "clumps" were also visible. Chain formation was mediated by the presence of epithelial cells. Clump formation was very specific on only the 5637 cell line. All enteropathogenic (eae+) E. coli (EPEC; n = 14) were able to form microcolonies which was cell line specific for each isolate. Most EPEC formed microcolonies on intestinal IPEC-J2 and Caco-2 but several also on urinary tract cells. Shigatoxin-producing (stx+) E. coli (n = 10) showed no specific adhesion patterns.
CONCLUSIONS:
E. coli isolates were highly diverse. Commensal and pathogenic isolates can adhere in various forms, including diffuse distribution, microcolonies, chains and clumps. Microcolony formation seems to be a global adhesion strategy also for commensal E. coli.
DNA damage assessment and potential applications in laboratory diagnostics and precision medicine
(2018)
Background and Aims
There is an increasing incidence of inflammatory bowel disease [IBD]. Autoimmune responses are involved in the pathophysiology of IBD, but their underlying pathways and target antigens have not yet been fully elucidated.
Methods
Autoantigenic targets in IBD were identified after separation of whole cell proteins isolated from neutrophils using two-dimensional electrophoresis and matrix assisted laser desorption ionization – time of flight mass spectrometry-based protein identification of the spots that displayed Western blotting signals with anti-neutrophil cytoplasmic antibody-positive sera. The prevalence of IgG, IgA and secretory IgA [sIgA] to chitinase 3-like protein 1 [CHI3L1] was analysed by enzyme-linked immunosorbent assays using recombinant CHI3L1 in 110 patients with Crohn’s disease [CD], 95 with ulcerative colitis [UC], 126 with coeliac disease [CeD] and 86 healthy controls [HCs].
Results
The 18-glycosylhydrolase family member CHI3L1 was identified as a neutrophil autoantigenic target. CD patients displayed significantly higher levels of IgG to CHI3L1 than patients with UC and CeD (p < 0.0001, respectively). IgA and sIgA to CHI3L1 was significantly higher in CD than in UC, CeD and HCs [p < 0.0001, respectively]. IgA and sIgA to CHI3L1 demonstrated the highest prevalence in CD [25.5%, 28/110; and 41.8%%, 46/110] compared to HCs [2.3%, 2/86; and 4.7%%, 4/86; p = 0.0015 and p < 0.0001] and are associated with a more complicated progression of CD.
Conclusion
CHI3L1 is a novel neutrophil autoantigenic target in CD. IgA and sIgA to CHI3L1 may serve as novel markers for CD and may facilitate the serological diagnosis of IBD.
Antibodies executing catalytic activity are referred to as antibody enzymes or short “abzymes” and may have diagnostic relevance. Abzymes with deoxyribonuclease (DNase) activity have been demonstrated in patients with autoimmune and infectious diseases. Despite several reports on the occurrence of DNase abzymes in systemic autoimmune rheumatic diseases, conclusive data about DNase activity of antibodies in patients with spondyloarthritides (SpAs) are lacking. In recent cross-sectional studies evaluating levels of IgG DNase activity in patients with psoriatic arthritis (PsA), reactive arthritis (ReA), and ankylosing spondylitis (AS), DNase activity of IgG has been assessed by the rivanol clot method and confirmed by agarose gel electrophoresis. Remarkably, levels of IgG DNase activity were significantly higher in sera of SpA patients than those in control subjects. In patients with PsA, ReA, and AS, a positive correlation of DNase IgG activity with synovitis, disease activity, and stage of spondylitis was observed, respectively. Given the involvement of autoimmune reactions in cytolysis and connective tissue degradation in PsA, ReA, and to a lesser extent in AS, abzymes might have an impact on the pathophysiology of SpAs. Detection of IgG DNase activity in patients suffering from SpA represents an exciting new research field and may assist in the differential diagnosis of SpA.
Evidence of Crohn's disease-related anti-glycoprotein 2 antibodies in patients with celiac disease
(2015)
Autoantibodies to asialoglycoprotein receptor (ASGPR) in patients with autoimmune liver diseases
(2015)
Background:
Escherichia coli have become the enterobacteriaceae species most affected by extended-spectrum β-lactamases (ESBLs) in view of the emergence of CTX-M-type ESBLs. These CTX-M-positive E. coli have been reported in numerous regions worldwide. Virulence determinants of already reported CTX-M-positive E. coli were investigated.
Methodology:
To gain insights into the mechanism underlying this phenomenon, we assessed serogroup, susceptibility pattern and diversity of virulence profiles within a collection of nine blaCTX-M-positive E. coli strains and their virulent determinant using miniaturized DNA microarray techniques. The nine ESBL-positive E. coli isolates were from eight male and one female patient(s) selected for study based on previous work. Virulence potential was inferred by detection of 63 virulence factor (VF) genes.
Results:
Four (44.4%) of the 9 E. coli isolates exhibited the same set of core characteristics: serotype O8:Hnt, while all were positive for OXA-1, ciprofloxacin resistance. Five of the isolates exhibited highly similar (91% to 100%) VF profiles.
Conclusion:
The findings describe a broadly disseminated, blaCTX-M-positive and virulent E. coli serogroup with highly homogeneous virulence genotypes, suggesting recent emergence in this zone. Understanding how this clone has emerged and successfully disseminated within the hospital and community, including across national boundaries, should be a public health priority.