title: Prevalence and epidemiological relationship of CMY-2 AmpC β-lactamase and CTX-M extended-spectrum β-lactamase-producing Escherichia coli isolates from broiler farms in Japan.
abstract: To evaluate the prevalence of extended-spectrum cephalosporin (ESC)-resistant Enterobacteriaceae in broiler chickens, 41 rectal samples taken from 4 commercial farms were examined. Desoxycholate hydrogen sulfide lactose agars, supplemented with either 4 μg/ml cefotaxime or 16 μg/ml ceftazidime, were used to screen ESC-resistant bacteria. ESC-resistant bacteria were isolated from all samples. Of the 164 ESC-resistant bacteria (included 4 isolates per a sample), 163 were Escherichia coli, while 1 isolate was identified as Enterobacter cloacae. Extended-spectrum β-lactamase (ESBL) genes and plasmid-mediated AmpC β-lactamase genes in the isolates were determined by PCR and sequencing. One AmpC β-lactamase gene, bla(CMY-2) (66%), and 4 ESBL genes, bla(CTX-M-1) (26%), bla(CTX-M-55) (10%), bla(SHV-5) (4%) and bla(CTX-M-2) (3%), were detected in the E. coli isolates. The epidemiological relationship of the CMY-2 and CTX-M β-lactamase-producing isolates among the farms was analyzed by pulsed-field gel electrophoresis using the XbaI restriction enzyme. Forty-one (Y1-Y41) and 14 (X1-X14) clusters were found in the CMY-2 and CTX-M-carrying E. coli isolates, respectively. Some clusters included isolates derived from more than 1 farm, indicating some cross-contamination of clonal strains and spread of CMY-2 AmpC β-lactamase or CTX-M ESBL among the farms.
authors.affiliation: Yamaguchi Prefectural Institute of Public Health and Environment, 2-5-67 Aoi, Yamaguchi 753-0821, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Kameyama
authors.forename: Takehisa
authors.initials: T
authors.lastname: Chuma
authors.forename: Junko
authors.initials: J
authors.lastname: Yabata
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Tominaga
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Iwata
authors.forename: Karoku
authors.initials: K
authors.lastname: Okamoto
mesh_terms: D000818:Animals; D001483:Base Sequence; D002439:Cefotaxime; D002442:Ceftazidime; D002645:Chickens; D017931:DNA Primers / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000201:enzymology*; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000662:veterinary*; D029968:Escherichia coli Proteins / Q000378:metabolism; D007564:Japan / Q000453:epidemiology; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011201:Poultry Diseases / Q000453:epidemiology* / Q000382:microbiology*; D015995:Prevalence; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D001618:beta-Lactamases / Q000378:metabolism
chemical_list: D017931:DNA Primers; D029968:Escherichia coli Proteins; D002442:Ceftazidime; C412613:CTX-M-9 protein, E coli; C103022:beta-lactamase CMY-2; D001618:beta-Lactamases; D002439:Cefotaxime