title: Detection of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli on flies at poultry farms.
abstract: In the Netherlands, extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli bacteria are highly prevalent in poultry, and chicken meat has been implicated as a source of ESBL-producing E. coli present in the human population. The current study describes the isolation of ESBL-producing E. coli from house flies and blow flies caught at two poultry farms, offering a potential alternative route of transmission of ESBL-producing E. coli from poultry to humans. Overall, 87 flies were analyzed in 19 pools. ESBL-producing E. coli bacteria were detected in two fly pools (10.5%): a pool of three blow flies from a broiler farm and a pool of eight house flies from a laying-hen farm. From each positive fly pool, six isolates were characterized and compared with isolates obtained from manure (n = 53) sampled at both farms and rinse water (n = 10) from the broiler farm. Among six fly isolates from the broiler farm, four different types were detected with respect to phylogenetic group, sequence type (ST), and ESBL genotype: A0/ST3519/SHV-12, A1/ST10/SHV-12, A1/ST58/SHV-12, and B1/ST448/CTX-M-1. These types, as well as six additional types, were also present in manure and/or rinse water at the same farm. At the laying-hen farm, all fly and manure isolates were identical, carrying blaTEM-52 in an A1/ST48 genetic background. The data imply that flies acquire ESBL-producing E. coli at poultry farms, warranting further evaluation of the contribution of flies to dissemination of ESBL-producing E. coli in the community.
authors.affiliation: National Institute for Public Health and the Environment (RIVM), Laboratory for Zoonoses and Environmental Microbiology, BA Bilthoven, The Netherlands.
authors.forename: Hetty
authors.initials: H
authors.lastname: Blaak
authors.forename: Raditijo A
authors.initials: RA
authors.lastname: Hamidjaja
authors.forename: Angela H A M
authors.initials: AH
authors.lastname: van Hoek
authors.forename: Lianne
authors.initials: L
authors.lastname: de Heer
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: de Roda Husman
authors.forename: Franciska M
authors.initials: FM
authors.lastname: Schets
mesh_terms: D000818:Animals; D002645:Chickens; D004175:Diptera / Q000382:microbiology*; D004926:Escherichia coli / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification*; D005838:Genotype; D006801:Humans; D008372:Manure / Q000382:microbiology; D017720:Molecular Epidemiology; D058889:Molecular Typing; D009426:Netherlands; D017422:Sequence Analysis, DNA; D014871:Water Microbiology; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism*
chemical_list: D008372:Manure; D001618:beta-Lactamases