Staff Publications

Staff Publications

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Transmission of antibiotic resistance from animals to humans : Broilers as a reservoir of ESBL-producing bacteria
Huijbers, P.M.C. - \ 2016
University. Promotor(en): Mart de Jong; Lisette Graat; E. van Duijkeren. - Wageningen : Wageningen University - ISBN 9789462576216 - 156 p.
broilers - man - disease transmission - antibiotic resistance - bacteria - enterobacteriaceae - poultry farming - epidemiology - vleeskuikens - mens - ziekteoverdracht - antibioticaresistentie - bacteriën - pluimveehouderij - epidemiologie

Huijbers, P.M.C. (2016). Transmission of antibiotic resistance from animals to humans: Broilers as a reservoir of ESBL-producing bacteria. PhD thesis, Wageningen University, Wageningen, the Netherlands.

Antibiotic resistance in animals becomes a public health issue when there is transmission of antibiotic resistant bacteria, or their resistance genes, from animals to humans. β-lactam antibiotics are critically important for the treatment of human bacterial infections. Resistance to this class of antibiotics, mediated by extended-spectrum β-lactamases (ESBL) has emerged. Broilers might contribute to transmission to humans due to the high prevalence of ESBL-producing Enterobacteriaceae among their intestinal biome, compared to other livestock species, companion animals, and wildlife. Transmission to humans might occur via the food chain, by direct contact or via the environment. The aim was to investigate transmission of antibiotic resistant bacteria between animals and humans, and more specifically transmission of ESBL-producing E. coli between broilers, and between broilers and humans in varying degrees of contact with these animals. Systematically collected and categorised evidence from literature showed that clinically relevant antibiotic resistant bacteria were present in the natural environment, that is in soil, water, air and wildlife. It was therefore hypothesised that humans in areas with high broiler densities might have an increased risk for carriage of ESBL-producing Enterobacteriaceae. This hypothesis was rejected, as the observed risk was lower for these individuals. The situation might be different for individuals living on broiler farms as ESBL-producing E. coli were detected on all investigated farms. Among broilers, the within farm prevalence approached 100%, and there was no difference between conventional and organic farms at five weeks, i.e. just before slaughter on conventional farms. On organic farms, the prevalence decreased to 80.0% at 70 days, i.e. slaughter age. Not only transmission to humans via the farm environment, but close physical contact with broilers might, therefore, lead to increased risk for carriage. Prevalence among farmers, their family members and employees on both conventional (19.1%) and organic (18.5%) broiler farms was higher compared to humans in the general population (5.1%). Moreover, people in close contact with live broilers showed the highest risk (27.1 vs. 14.3%). Evidence for clonal transmission of ESBL-producing E. coli between humans and broilers was found on conventional farms, and horizontal gene transfer was suspected on both conventional and organic farms. Even without selection pressure from antibiotics ESBL-producing E. coli were able to transmit and persist in an organic broiler flock, which shows that broilers form a reservoir of antibiotic resistance genes. This leads to an increased risk of carriage of humans on farms through direct contact with broilers and possibly via the direct farm environment. As only a very small percentage of the general population is exposed to live broilers, direct contact with broilers does not appear to be important for carriage in the general human population.

Extended-spectrum and AmpC B-lactamase-producing Escherichia coli in broilers and peoplelivingand/or working on broiler farms: prevalence, risk factors and molecular characteristics
Huijbers, P.M.C. ; Graat, E.A.M. ; Haenen, A.P.J. ; Santen, M.G. van; Essen-Zandbergen, A. van; Mevius, D.J. ; Duijkeren, E. van; Hoek, A.H.A.M. van - \ 2014
Journal of Antimicrobial Chemotherapy 69 (2014)10. - ISSN 0305-7453 - p. 2669 - 2675.
livestock-associated mrsa - enterobacteriaceae - netherlands - humans - identification - plasmids - poultry - genes - meat - pcr
OBJECTIVES: The objectives of this study were to: estimate the prevalence of extended-spectrum ß-lactamase (ESBL)- and AmpC ß-lactamase-producing Escherichia coli carriage among broiler farmers, their family members and employees; identify and quantify risk factors for carriage, with an emphasis on contact with live broilers; and compare isolates from humans and broilers within farms with respect to molecular characteristics to gain insight into transmission routes. METHODS: A cross-sectional prevalence study was conducted on 50 randomly selected Dutch broiler farms. Cloacal swabs were taken from 20 randomly chosen broilers. Faecal swabs were returned by 141 individuals living and/or working on 47 farms. ESBL/AmpC-producing E. coli were isolated and, for selected isolates, phylogenetic groups, plasmids and sequence types were determined. Questionnaires were used for risk factor analysis. RESULTS: All sampled farms were positive, with 96.4% positive pooled broiler samples. The human prevalence was 19.1%, with 14.3% and 27.1% among individuals having a low and a high degree of contact with live broilers, respectively. Five pairs of human-broiler isolates had identical genes, plasmid families and E. coli sequence types, showing clonal transmission. Furthermore, similar ESBL/AmpC genes on the same plasmid families in different E. coli sequence types in humans and broilers hinted at horizontal gene transfer. CONCLUSIONS: The prevalence among people on broiler farms was higher than in previous studies involving patients and the general population. Furthermore, an increased risk of carriage was shown among individuals having a high degree of contact with live broilers. The (relative) contribution of transmission routes that might play a role in the dissemination of ESBL/AmpC-encoding resistance genes to humans on broiler farms should be pursued in future studies.
Presence of ESBL/AmpC-producing Escherichia coli in the broiler production pyramid: a descriptive study.
Dierikx, C.M. ; Goot, J.A. van der; Smith, H.E. ; Kant, A. ; Mevius, D.J. - \ 2013
PLoS One 8 (2013). - ISSN 1932-6203 - 11 p.
spectrum-beta-lactamase - antimicrobial agents - resistance - chickens - poultry - enterobacteriaceae - epidemiology - transmission - humans - impact
Broilers and broiler meat products are highly contaminated with extended spectrum beta-lactamase (ESBL) or plasmid-mediated AmpC beta-lactamase producing Escherichia coli and are considered to be a source for human infections. Both horizontal and vertical transmission might play a role in the presence of these strains in broilers. As not much is known about the presence of these strains in the whole production pyramid, the epidemiology of ESBL/AmpC-producing E. coli in the Dutch broiler production pyramid was examined. Cloacal swabs of Grandparent stock (GPS) birds (one-/two-days (breed A and B), 18 and 31 weeks old (breed A)), one-day old Parent stock birds (breed A and B) and broiler chickens of increasing age (breed A) were selectively cultured to detect ESBL/AmpC-producing isolates. ESBL/AmpC-producing isolates were found at all levels in the broiler production pyramid in both broiler breeds examined. Prevalence was already relatively high at the top of the broiler production pyramid. At broiler farms ESBL/AmpC producing E. coli were still present in the environment of the poultry house after cleaning and disinfection. Feed samples taken in the poultry house also became contaminated with ESBL/AmpC producing E. coli after one or more production weeks. The prevalence of ESBL/AmpC-positive birds at broiler farms increased within the first week from 0–24% to 96–100% independent of the use of antibiotics and stayed 100% until slaughter. In GPS breed A, prevalence at 2 days, 18 weeks and 31 weeks stayed below 50% except when beta-lactam antibiotics were administered. In that case prevalence increased to 100%. Interventions minimizing ESBL/AmpC contamination in broilers should focus on preventing horizontal and vertical spread, especially in relation to broiler production farms.
Characteristics of Cefotaxime-Resistant Escherichia coli from Wild Birds in The Netherlands
Veldman, K.T. ; Tulden, P. ; Kant, A. ; Testerink, J.J. ; Mevius, D.J. - \ 2013
Applied and Environmental Microbiology 79 (2013)24. - ISSN 0099-2240 - p. 7556 - 7561.
spectrum-beta-lactamase - extended-spectrum - antibiotic-resistance - natural reserve - ctx-m - salmonella - plasmids - gulls - enterobacteriaceae - environments
Cloacal swabs from carcasses of Dutch wild birds obtained in 2010 and 2011 were selectively cultured on media with cefotaxime to screen for the presence of extended-spectrum beta-lactamase (ESBL)/AmpC-producing Escherichia coli. Subsequently, all cefotaxime-resistant E. coli isolates were tested by broth microdilution and microarray. The presence of ESBL/AmpC and coexisting plasmid-mediated quinolone resistance (PMQR) genes was confirmed by PCR and sequencing. To determine the size of plasmids and the location of ESBL and PMQR genes, S1 pulsed-field gel electrophoresis (PFGE) was performed on transformants, followed by Southern blot hybridization. The study included 414 cloacal swabs originating from 55 different bird species. Cefotaxime-resistant E. coli isolates were identified in 65 birds (15.7%) from 21 different species. In all, 65 cefotaxime-resistant E. coli ESBL/AmpC genes were detected, mainly comprising variants of bla(CTX-M) and bla(CMY-2). Furthermore, PMQR genes [aac(6')-lb-cr, qnrB1, and qnrS1] coincided in seven cefotaxime-resistant E. coli isolates. Overall, replicon typing of the ESBL/AmpC-carrying plasmids demonstrated the predominant presence of IncI1 (n = 31) and variants of IncF (n = 18). Our results indicate a wide dissemination of ESBL and AmpC genes in wild birds from The Netherlands, especially among aquatic-associated species (waterfowl, gulls, and waders). The identified genes and plasmids reflect the genes found predominantly in livestock animals as well as in humans.
Cross-sectional study on prevalence and molecular characteristics of plasmid mediated ESBL/AmpC-producing Escherichia coli isolated from veal calves at slaughter
Hordijk, J. ; Wagenaar, J.A. ; Kant, A. ; Essen-Zandbergen, A. van; Dierikx, C.M. ; Veldman, K. ; Wit, B. ; Mevius, D.J. - \ 2013
PLoS One 8 (2013)5. - ISSN 1932-6203
spectrum-beta-lactamase - food-producing animals - extended-spectrum - ctx-m - salmonella-enterica - fecal carriage - antimicrobial resistance - host-range - cattle - enterobacteriaceae
Objectives - The presence of ESBL/AmpC-producing E. coli in cattle has been reported previously, however information on veal calves is limited. This study describes the prevalence and molecular characteristics of E. coli with non-wild type susceptibility to cefotaxime in veal calves at slaughter. Methods - Faecal samples from 100 herds, 10 individual animals per herd, were screened for E. coli with non-wild type susceptibility for cefotaxime. Molecular characterization of ESBL/AmpC genes and plasmids was performed on one isolate per herd by microarray, PCR and sequence analysis. Results - 66% of the herds were positive for E. coli with non-wild type susceptibility for cefotaxime. Within-herd prevalence varied from zero to 90%. 83% of E. coli producing ESBL/AmpC carried blaCTX-M genes, of which blaCTX-M-1, blaCTX-M-14 and blaCTX-M-15 were most prevalent. The dominant plasmids were IncI1 and IncF-type plasmids. Conclusions - A relatively high prevalence of various blaCTX-M producing E. coli was found in veal calves at slaughter. The genes were mainly located on IncI1 and IncF plasmids.
Comprehensive analysis of B-Lactam antibiotics including penicillins, cephalosporins and carbapenems in poultry muscle using liquid chromatography coupled to tandem mass spectrometry
Berendsen, B.J.A. ; Gerritsen, H.W. ; Wegh, R.S. ; Lameris, S.L. ; Sebille, R. van; Stolker, A.A.M. ; Nielen, M.W.F. - \ 2013
Analytical and Bioanalytical Chemistry 405 (2013)24. - ISSN 1618-2642 - p. 7859 - 7874.
beta-lactamase - quantitative-analysis - ceftiofur resistance - escherichia-coli - european-union - bovine muscle - kidney tissue - enterobacteriaceae - salmonella - mechanisms
A comprehensive method for the quantitative residue analysis of trace levels of 22 ß-lactam antibiotics, including penicillins, cephalosporins, and carbapenems, in poultry muscle by liquid chromatography in combination with tandem mass spectrometric detection is reported. The samples analyzed for ß-lactam residues are hydrolyzed using piperidine in order to improve compound stability and to include the total residue content of the cephalosporin ceftifour. The reaction procedure was optimized using a full experimental design. Following detailed isotope labeling, tandem mass spectrometry studies and exact mass measurements using high-resolution mass spectrometry reaction schemes could be proposed for all ß-lactams studied. The main reaction occurring is the hydrolysis of the ß-lactam ring under formation of the piperidine substituted amide. For some ß-lactams, multiple isobaric hydrolysis reaction products are obtained, in accordance with expectations, but this did not hamper quantitative analysis. The final method was fully validated as a quantitative confirmatory residue analysis method according to Commission Decision 2002/657/EC and showed satisfactory quantitative performance for all compounds with trueness between 80 and 110 % and within-laboratory reproducibility below 22 % at target level, except for biapenem. For biapenem, the method proved to be suitable for qualitative analysis only.
Extended-spectrum-ß-lactamase- and AmpC-ß-lactamase-producing Escherichia coli in Dutch broilers and broiler farms
Dierikx, C.M. ; Goot, J.A. van der; Fabri, T. ; Essen-Zandbergen, A. van; Smith, H.E. ; Mevius, D.J. - \ 2013
Journal of Antimicrobial Chemotherapy 68 (2013)1. - ISSN 0305-7453 - p. 60 - 67.
salmonella-enterica - resistance genes - plasmids - humans - food - animals - poultry - chicken - enterobacteriaceae - identification
Objectives The aim of this study was to establish the prevalence of extended-spectrum ß-lactamase (ESBL)- and AmpC ß-lactamase-producing Escherichia coli at Dutch broiler farms and in farmers and to compare ESBL/AmpC-producing isolates from farmers and their animals. Methods Twenty-five to 41 cloacal swabs collected from broilers at each of 26 farms and 18 faecal samples from 18 broiler farmers were analysed for determination of the presence of ESBL/AmpC-producing E. coli. ESBL/AmpC genes were characterized by microarray, PCR and sequencing. Plasmids were characterized by transformation and PCR-based replicon typing. Subtyping of plasmids was done by plasmid multilocus sequence typing or restriction fragment length polymorphism. E. coli genotypes were determined by multilocus sequence typing. Results Birds from all farms were positive for ESBL/AmpC-producing E. coli, and on 22/26 farms the within-farm prevalence was =80%. Six of 18 farmers carried isolates containing ESBL/AmpC genes blaCTX-M-1, blaCMY-2 and/or blaSHV-12, which were also present in the samples from their animals. In five of these isolates, the genes were located on identical plasmid families [IncI1 (n¿=¿3), IncK (n¿=¿1) or IncN (n¿=¿1)], and in isolates from two farmers the genes were carried on identical plasmid subtypes (IncI1 ST12 and IncN ST1, where ST stands for sequence type) as in the isolates from their animals. Conclusions This study shows a high prevalence of birds carrying ESBL/AmpC-producing E. coli at Dutch broiler farms and a high prevalence of ESBL/AmpC-producing E. coli in farmers. This is undesirable due to the risk this poses to human health. Future research should focus on identification of the source of these isolates in the broiler production chain to make interventions resulting in reduction of these isolates possible.
Sequence-function-stability relationships in proteins from datasets of functionally annotated variants: The case of TEM beta-lactamases
Abriata, L.A. ; Salverda, M.L.M. ; Tomatis, P.E. - \ 2012
FEBS Letters 586 (2012)19. - ISSN 0014-5793 - p. 3330 - 3335.
antibiotic-resistance - directed evolution - natural evolution - chemical-properties - global suppressor - in-vitro - enterobacteriaceae - classification - prediction - pathways
A dataset of TEM lactamase variants with different substrate and inhibition profiles was compiled and analyzed. Trends show that loops are the main evolvable regions in these enzymes, gradually accumulating mutations to generate increasingly complex functions. Notably, many mutations present in evolved enzymes are also found in simpler variants, probably originating functional promiscuity. Following a function-stability tradeoff, the increase in functional complexity driven by accumulation of mutations fosters the incorporation of other stability-restoring substitutions, although our analysis suggests they might not be as "global" as generally accepted and seem instead specific to different networks of protein sites. Finally, we show how this dataset can be used to model functional changes in TEMs based on the physicochemical properties of the amino acids.
Microbial performance of food safety management systems implemented in the lamb production chain
Oses, S.M. ; Luning, P.A. ; Jacxsens, L. ; Santillana, S. ; Jaime, I. ; Rovira, J. - \ 2012
Journal of Food Protection 75 (2012)1. - ISSN 0362-028X - p. 95 - 103.
escherichia-coli o157 - beef processing plants - aerobic-bacteria - red meat - carcasses - prevalence - contamination - enterobacteriaceae - campylobacter - salmonella
The actual microbial status of the lamb production chain at three slaughterhouses, one processing plant, and five butcher shops selling whole or cut lamb carcasses to consumers was assessed with a previously developed microbial assessment scheme. All studied establishments had a food safety management system (FSMS) that was implemented according to legislative requirements. Microbial safety level profiles were constructed for each establishment and provided clear indications of which pathogens, hygiene indicators, or utility parameters required attention to improve the performance of the microbiological control protocols of the implemented FSMS. The highest contamination was found in the slaughterhouses in samples taken from the meat products (aerobic mesophilic plate counts [AMPs] of 3.40 to 6.63 log CFU/cm(2) and Enterobacteriaceae counts of 1.00 to 4.62 log CFU/cm(2)), contact surfaces (AMPs of 2.44 to 8.92 log CFU/cm(2)), and operators' hands and/or gloves (AMPs of 2.84 to 8.09 log CFU/cm(2)), especially after hide removal and evisceration. The microbial assessment scheme is a useful tool for providing insight into the actual microbiological results achieved with an FSMS implemented in establishments at various stages along the lamb production chain.
Detection and characterization of pCT-like plasmid vectors for blaCTX-M-14 in Escherichia coli isolates from humans, turkeys and cattle in England and Wales
Stokes, M.O. ; Cottel, J.L. ; Piddock, L.J. ; Wu, G. ; Wootton, M. ; Mevius, D.J. ; Randall, L.P. ; Teale, C.J. ; Fielder, M.D. ; Coldham, N.G. - \ 2012
Journal of Antimicrobial Chemotherapy 67 (2012)7. - ISSN 0305-7453 - p. 1639 - 1644.
spectrum-beta-lactamase - ctx-m - salmonella - ctx-m-14 - enterobacteriaceae - resistance - strains - france - gene - uk
Objectives - To detect and characterize Escherichia coli strains and pCT-like plasmids implicated in the dissemination of the CTX-M-14 gene in animals and humans, in England and Wales. Methods UK CTX-M-14-producing E. coli (n¿=¿70) from cattle (n¿=¿33), turkeys (n¿=¿9), sheep (n¿=¿2) and humans (n¿=¿26) were screened using multiplex PCR for the detection of a previously characterized plasmid, pCT. Isolates found to be carrying two or more pCT genetic markers were further analysed using PFGE. Their antimicrobial-resistance genes and virulence genes were also determined. These plasmids were transferred to Salmonella enterica serotype Typhimurium 26R and further examined for incompatibility type, genetic environment of the blaCTX-M-14 gene, size, restriction fragment length polymorphism (RFLP) and nikB sequence. Results - The 25 E. coli isolates carrying pCT genetic markers generated 19 different PFGE profiles, and 23 isolates had different virulence and antimicrobial-resistance gene patterns. One isolate from cattle was a verotoxigenic E. coli (‘VTEC’); the rest were commensal or extra-intestinal pathogenic E. coli. pCT-like plasmids with similar molecular characteristics (size, replicon type, RFLP pattern, pCT markers and genetic environment of the blaCTX-M-14 gene) were detected in 21/25 of the field isolates, which comprised those from cattle (n¿=¿9), turkeys (n¿=¿8) and humans (n¿=¿4). All pCT-like plasmids were conjugative, and most were IncK (n¿=¿21) and had the same local genetic environment flanking the blaCTX-M-14 gene (n¿=¿23). RFLP analysis demonstrated =75% similarity among most plasmids (n¿=¿22). Conclusions - pCT-like plasmids were common vectors for horizontal dissemination of 30% of the blaCTX-M-14 genes to
Occurrence and characteristics of extended-spectrum-ß-lactamase- and AmpC-producing clinical isolates derived from companion animals and horses
Dierikx, C.M. ; Duijkeren, E. van; Schoormans, A. ; Essen-Zandbergen, A. van; Veldman, K.T. ; Kant, A. ; Huijsdens, X. ; Zwaluw, K. van der; Wagenaar, J.A. ; Mevius, D.J. - \ 2012
Journal of Antimicrobial Chemotherapy 67 (2012)6. - ISSN 0305-7453 - p. 1368 - 1374.
mediated quinolone resistance - escherichia-coli - salmonella-enterica - beta-lactamases - antimicrobial resistance - genes - enterobacteriaceae - cephalosporins - identification - epidemiology
To investigate the occurrence and characteristics of extended-spectrum -lactamase (ESBL)- and AmpC-producing Enterobacteriaceae isolates in clinical samples of companion animals and horses and compare the results with ESBL/AmpC-producing isolates described in humans. Between October 2007 and August 2009, 2700 Enterobacteriaceae derived from clinical infections in companion animals and horses were collected. Isolates displaying inhibition zones of 25 mm for ceftiofur and/or cefquinome by disc diffusion were included. ESBL/AmpC production was confirmed by combination disc tests. The presence of resistance genes was identified by microarray, PCR and sequencing, Escherichia coli genotypes by multilocus sequence typing and antimicrobial susceptibility by broth microdilution. Sixty-five isolates from dogs (n38), cats (n14), horses (n12) and a turtle were included. Six Enterobacteriaceae species were observed, mostly derived from urinary tract infections (n32). All except 10 isolates tested resistant to cefotaxime and ceftazidime by broth microdilution using clinical breakpoints. ESBL/AmpC genes observed were bla(CTX-M-1, -2, -9, -14, -15,) bla(TEM-52), bla(CMY-2) and bla(CMY-39). bla(CTX-M-1) was predominant (n17). bla(CTX-M-9) occurred in combination with qnrA1 in 3 of the 11 Enterobacter cloacae isolates. Twenty-eight different E. coli sequence types (STs) were found. E. coli carrying bla(CTX-M-1) belonged to 13 STs of which 3 were previously described in Dutch poultry and patients. This is the first study among a large collection of Dutch companion animals and horses characterizing ESBL/AmpC-producing isolates. A similarity in resistance genes and E. coli STs among these isolates and isolates from Dutch poultry and humans may suggest exchange of resistance between different reservoirs.
Diversity in biofilm formation and production of curli fimbriae and cellulose of Salmonella Thyphimurium strains of different origin in high and low nutrient medium
Castelijn, G.A.A. ; Veen, S. van der; Zwietering, M.H. ; Moezelaar, R. ; Abee, T. - \ 2012
Biofouling 28 (2012)1. - ISSN 0892-7014 - p. 51 - 63.
enterica serovar typhimurium - air-liquid interface - listeria-monocytogenes - multicellular morphotype - gastrointestinal-tract - agfd promoter - behavior - enterobacteriaceae - enteritidis - persistence
The biofilm forming behavior of 51 Salmonella Typhimurium strains was determined in Tryptone Soya Broth (TSB) and 20 times diluted TSB (1/20TSB) at 25°C and 37°C. The results indicated that biofilm forming behavior is influenced by environmental conditions and associated with the origin of the strains. Clinical, outbreak-associated and retail product isolates showed dense biofilm formation in both media at 25°C, and in TSB also at 37°C. However, industrial isolates only showed dense biofilm formation in 1/20TSB at 25°C. By enumeration of biofilm cells, LIVE/DEAD staining and SEM analysis of biofilms it was found that the ratio of cells and extracellular matrix is affected by environmental conditions. Indeed, the genes involved in curli fimbriae and cellulose production are highly induced during biofilm formation at 25°C in 1/20TSB. This indicates that these are important matrix components during biofilm formation in 1/20TSB at 25°C and that other factors contribute to biofilm formation of clinical, outbreak-associated and retail product isolates at 37°C and/or nutrient-rich conditions
International collaborative study on the occurrence of plasmid mediated quinolone resisitance in Salmonella enterica en Escherichia coli isolated from animals, humans, food and the environment in 13 European countries.
Veldman, K.T. ; Cavaco, L.M. ; Mevius, D.J. ; Battisti, A. ; Botteldoorn, N. ; Bruneau, M. ; Cerny, T. ; Franco, A. ; Frutos Escobar, C. De; Guerra, B. ; Gutierrez, M. ; Hopkins, K. ; Myllyniemi, A.L. ; Perrin-Guyomard, A. ; Schroeter, A. ; Sunde, M. ; Wasyl, D. ; Aarestrup, F.M. - \ 2011
Journal of Antimicrobial Chemotherapy 66 (2011)6. - ISSN 0305-7453 - p. 1278 - 1286.
qnr genes - determinant qnrs1 - modifying enzyme - clinical isolate - united-kingdom - 1st report - enterobacteriaceae - prevalence - mechanisms - strains
Objectives This study was initiated to collect retrospective information on the occurrence of plasmid-mediated quinolone resistance (PMQR) in Salmonella enterica and Escherichia coli isolates in Europe and to identify the responsible genes. Methods Databases of national reference laboratories containing MIC values for Salmonella and E. coli isolated between 1994 and 2009 in animals, humans, food and the environment from 13 European countries were screened for isolates exhibiting a defined quinolone resistance phenotype, i.e. reduced susceptibility to fluoroquinolones and nalidixic acid. PCR and sequence analysis were performed to identify the responsible PMQR genes. Results Screening of databases of 13 European countries resulted in a selection of 1215 Salmonella and 333 E. coli isolates. PMQR genes were identified in 59% of the Salmonella isolates and 15% of the E. coli isolates selected. In Salmonella, qnrS1 (n¿=¿125) and variants of qnrB (n¿=¿138) were frequently identified, whereas qnrA1 (n¿=¿3) and aac(6')-1b-cr (n¿=¿3) were rarely found. qnrD was detected in 22 Salmonella isolates obtained from humans and animals. In E. coli, qnrS1 was identified in 19 isolates and qnrB19 was found in one isolate. No qnrC or qepA genes were detected in either Salmonella or E. coli. Conclusions This study shows the occurrence and dissemination of PMQR genes in Salmonella and E. coli in Europe with a defined quinolone resistance phenotype. We also report the first detection of qnrD in Salmonella collected in Europe.
Increased detection of extended spectrum beta-lactamase producing Salmonella enterica and Escherichia coli isolates from poultry
Dierikx, C.M. ; Essen-Zandbergen, A. van; Veldman, K.T. ; Smith, H.E. ; Mevius, D.J. - \ 2010
Veterinary Microbiology 145 (2010)3-4. - ISSN 0378-1135 - p. 273 - 278.
gram-negative bacteria - resistance plasmid - ctx-m - enterobacteriaceae - animals - cephalosporins - identification - typhimurium - strains - genes
To gain more information on the genetic basis of the rapid increase in the number of isolates exhibiting non-wild type Minimum Inhibitory Concentrations (MICs) for cefotaxime observed since 2003, beta-lactamase genes of 22 Salmonella enterica and 22 Escherichia coli isolates from broilers in 2006 showing this phenotype were characterized by miniaturized micro-array, PCR and DNA-sequencing. Presence and size of plasmids were determined by S1-digest pulsed-field gel electrophoresis and further characterized by PCR-based replicon typing. Transfer of resistance plasmids was tested by conjugation and transformation experiments. To link resistance genes and plasmid type, Southern blot hybridization experiments were conducted. In 42 isolates, five (blaCTX-M-1, blaCTX-M-2, blaTEM-20, blaTEM-52, blaSHV-2) different extended spectrum beta-lactamase (ESBL)-genes and two (blaACC-1, blaCMY-2) AmpC-genes were present. Three of the detected ESBL-genes (blaCTX-M-1, blaTEM-52 and blaCTX-M-2) were located on similar types of plasmids (IncI1 and IncHI2/P) in both E. coli and Salmonella. Two other detected ESBL- and AmpC-genes blaSHV-2 and blaCMY-2 respectively (on IncK plasmids), were only found in E. coli, whereas the AmpC-gene blaACC-1 (on non-typable plasmids), and the ESBL-gene blaTEM-20 (on IncI1 plasmids), were only detected in Salmonella. In two isolates, no ESBL- or AmpC-gene could be detected through these methods. The increase in the number of E. coli and S. enterica isolates from the gastro-intestinal tract of broilers exhibiting non-wild type MICs for cefotaxime is mainly due to an increase in IncI1 plasmids containing blaCTX-M-1. The reason for the successful spread of this plasmid type in these species is not yet understood.
Enterobacteriën (waaronder coli-achtigen) : bacteriën in boerderijzuivel : informatieblad
Livestock Research, - \ 2010
Lelystad : Wageningen UR Livestock Research
enterobacteriaceae - escherichia coli - zuivelbedrijf op de boerderij - voedselveiligheid - voedselbesmetting - farm dairies - food safety - food contamination
In dit informatieblad worden de Enterobacteriën beschreven. Het gebruik van deze informatiebladen is vooral bedoeld voor mensen die werkzaam zijn in de boerderijzuivel en is een hulpmiddel om bij vragen snel iets na te kunnen zoeken.
Novel genetic environment of plasmid-mediated quinolone resistance gene qnrB2 in Salmonella Bredeney from poultry
Fortini, D. ; Garcia-Fernandez, A. ; Veldman, K.T. ; Mevius, D.J. ; Carattoli, A. - \ 2009
Journal of Antimicrobial Chemotherapy 64 (2009)6. - ISSN 0305-7453 - p. 1332 - 1334.
escherichia-coli - determinants - enterobacteriaceae - aac(6')-ib-cr - prevalence - emergence - qepa
Gezamenlijke toetsontwikkeling op Erwinia chrysanthemi in volle gang
Doorn, J. van; Dees, R.H.L. ; Martin, W.S. ; Vreeburg, P.J.M. ; Leeuwen, P.J. van - \ 2009
BloembollenVisie 2009 (2009)164. - ISSN 1571-5558 - p. 20 - 21.
tuinbouwbedrijven - proeven op proefstations - bloembollen - dickeya chrysanthemi - enterobacteriaceae - testen - market gardens - station tests - ornamental bulbs - testing
Erwinia bezorgde menig ondernemer de afgelopen jaren de nodige hoofdbrekens. Onderzoek door PPO reikte al een aantal oplossingen aan. Nader onderzoek is gedaan naar de mogelijkheid om partijen te toetsen. In dit artkel de achtergronden bij dit onderzoek
Evidence for recombination among the alleles encoding TEM and SHV ß-lactamases
Barlow, M. ; Fatollahi, J. ; Salverda, M.L.M. - \ 2009
Journal of Antimicrobial Chemotherapy 63 (2009)2. - ISSN 0305-7453 - p. 256 - 259.
hong-kong - spectrum - enterobacteriaceae - populations - selection - evolution - strains
Objectives: The objective of this research was to determine whether recombination occurs in class A ß-lactamases. Methods: We performed 2 analysis of the observed and expected numbers of times that ß-lactamases from the TEM, SHV and CTX-M groups co-occurred. Additionally, we performed phylogenetic analysis to detect independent occurrences of silent mutations in blaTEM and blaSHV variants. Results: We found that the distribution of co-occurring blaTEM, blaSHV and blaCTX-M alleles in clinical microbial populations is consistent with the regular occurrence of recombination among alleles within the groups. We also found that the distribution of silent mutations in blaTEM and blaSHV alleles is inconsistent with spontaneous point mutations. Conclusions: Our findings indicate that recombination has an important effect on the sequence evolution and population distribution of the alleles that encode class A ß-lactamases
Gezond plantgoed belangrijke stap tegen Erwinia
Vreeburg, P.J.M. ; Leeuwen, P.J. van; Vlaming, E.A.C. ; Doorn, J. van; Hollinger, T.C. - \ 2006
BloembollenVisie 4 (2006)90. - ISSN 1571-5558 - p. 24 - 25.
bloembollen - erwinia - enterobacteriaceae - plantenziekteverwekkende bacteriën - plantmateriaal - ziektebestrijding - landbouwkundig onderzoek - ornamental bulbs - plant pathogenic bacteria - planting stock - disease control - agricultural research
Ook in 2005 heeft Erwinia weer veel schade veroorzaakt. De reeds aanwezige besmetting in partijen en de weersomstandigheden hebben daaraan bijgedragen. PPO Bloembollen zet de ervaringen en resultaten uit het onderzoek in 2005 en de plannen voor 2006 op een rij. Steeds duidelijker komt het belang van gezond uitgangsmateriaal naar voren
Snelle toetsen op Erwinia geven steeds beter zicht op aantasting
Doorn, J. van; Hollinger, T.C. ; Vreeburg, P.J.M. ; Leeuwen, P.J. van; Wolf, J.M. van der; Speksnijder, A.G.C.L. - \ 2006
BloembollenVisie 4 (2006)87. - ISSN 1571-5558 - p. 22 - 23.
bloembollen - erwinia - enterobacteriaceae - methodologie - tests - bereikt resultaat - dna - serologie - landbouwkundig onderzoek - ornamental bulbs - methodology - achievement - serology - agricultural research
Om rot en snot in bloembollen als gevolg van Erwinia goed te kunnen aantonen, zijn diverse toetsen ontwikkeld. Op verschillende fronten is PPO in samenwerking met PRI bezig om snelle en betrouwbare methoden te ontwikkelen
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