1 Veterinary Clinical Microbiology, Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, Københavns Universitet2 Section of Microbiology, Department of Veterinary Disease Biology, Faculty of Life Sciences, Københavns Universitet3 unknown4 Veterinary Clinical Microbiology, Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, Københavns Universitet5 Section of Microbiology, Department of Veterinary Disease Biology, Faculty of Life Sciences, Københavns Universitet
a review of current problems, illustrated with some laboratory findings
Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli has been documented in humans as well as in food-producing birds, including chickens, and for unknown reasons the prevalence has increased significantly during the last decade. With E. coli as a major opportunistic pathogen in chickens and with a potential for zoonotic transfer to human beings, ESBL-producing E. coli represents a major risk both to poultry production and to human health. This review presents some of the current problems with ESBL-producing E. coli in relation to poultry production, with a focus on chickens. To illustrate issues in relation to screening and typing, two case studies are included where one collection of ESBL-producing E. coli isolates was obtained from asymptomatic carrier chickens while the other was obtained from lesions in chickens. Pulsed-field gel electrophoresis and multi-locus sequence typing revealed a highly heterogeneous population of ESBL-producing E. coli. All isolates harboured between one and three large plasmids (>100 kb). Among isolates associated with asymptomatic chickens, the ESBL types SHV and TEM dominated, while CTX-M-1 dominated in disease-associated isolates. The isolates from diseased birds were occasionally of sequence types often associated with human infections, such as ST131. With improved tools to trace and screen for ESBL-producing E. coli at farm level, strategies can be selected that aim to reduce or eliminate the presence of ESBL-producing E. coli in poultry and poultry products meant for human consumption.
Avian Pathology : Journal of the W.v.p.a, 2014, Vol 43, Issue 3, p. 199-208