title: Prevalence of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae in food-producing animals.
abstract: To evaluate the diversity of extended-spectrum β-lactamases (ESBL) genes among food-producing animals, 48 isolates of ESBL-producing Escherichia coli isolates were obtained from rectal samples of broilers, layers, beef cattle and pigs, at the slaughterhouse level. ESBL-carrying E. coli were isolated from 60.0% of individual broiler rectal samples, 5.9% of layers, 12.5% of beef cattle and 3% of pigs. One ESBL-producing Klebsiella pneumoniae was isolated from a broiler. The ESBL-positive E. coli isolates from broilers harbored various ESBL genes: bla (SHV-12), bla(CTX-M-2), bla(CTX-M-14), bla(CTX-M-15) and bla(CTX-M-44). The plasmid DNAs were analyzed by restriction patterns. Homogeneous band patterns were yielded in those of K. pneumoniae and E. coli isolates harboring the bla(CTX-M-2) gene from different farms. No genetic relation between the 2 CTX-M-14 ESBL-producing strains was found by pulsed-field gel electrophoresis, although 2 plasmids in these strains, obtained from different broiler farms, were similar to each other. This study provides evidence that the proliferation of CTX-M-producing E. coli is due to the growth of indigenous CTX-M-producing strains and the possible emergence of strains that acquired CTX-M genes by horizontal transfer in different broiler farms. CTX-M-producing coliforms in broilers should be controlled due to the critical importance of cephalosporins and the zoonotic potential of ESBL-producing bacteria.
authors: Department of Microbiology, Shizuoka Institute of Environment and Hygiene, 4–27–2 Kitaando, Aoi, Shizuoka 420–8637, Japan. midori1_hiroi@pref.shizuoka.lg.jp
authors: Midori
authors: M
authors: Hiroi
authors: Fumie
authors: F
authors: Yamazaki
authors: Tetsuya
authors: T
authors: Harada
authors: Naomi
authors: N
authors: Takahashi
authors: Natsuko
authors: N
authors: Iida
authors: Yoshihiro
authors: Y
authors: Noda
authors: Miya
authors: M
authors: Yagi
authors: Tomohiro
authors: T
authors: Nishio
authors: Takashi
authors: T
authors: Kanda
authors: Fumihiko
authors: F
authors: Kawamori
authors: Kanji
authors: K
authors: Sugiyama
authors: Takashi
authors: T
authors: Masuda
authors: Yukiko
authors: Y
authors: Hara-Kudo
authors: Norio
authors: N
authors: Ohashi
mesh_terms: D000818:Animals; D002417:Cattle; D002645:Chickens; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field / Q000662:veterinary; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D005243:Feces / Q000382:microbiology; D005516:Food Microbiology; D007711:Klebsiella pneumoniae / Q000201:enzymology* / Q000235:genetics; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D010957:Plasmids / Q000737:chemistry / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000662:veterinary; D013552:Swine; D001618:beta-Lactamases / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D004269:DNA, Bacterial; C456080:beta-lactamase CTX-M-14; D001618:beta-Lactamases