title: Detection of CTX-M-15, CTX-M-22, and SHV-2 extended-spectrum beta-lactamases (ESBLs) in Escherichia coli fecal-sample isolates from pig farms in China.
abstract: The aim of the present study was to investigate the antibiotic resistance profiles and the molecular epidemiology of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli isolates from two production swine operations in Sichuan Province, China, between August 2002 and February 2007. The prevalence of ESBL-producing E. coli increased dramatically from 2.2% to 10.7% during this period. This increase appeared mostly related to dissemination of CTX-M-type ESBLs among E. coli isolates. Of 212 E. coli isolates studied, 14 harbored ESBL genes. Among them, 13 harbored bla(CTX-M-15/22) and one harbored bla(SHV-2). To our knowledge, this is the first study to identify bla(CTX-M-22) from production animals. One isolate in 2002 harbored bla(SHV-2), indicating that ESBL genes have been present in farm animals in China since at least 2002. Molecular characterization and pulsed-field gel electrophoresis of the ESBL-producing isolates suggested that different mechanisms may be involved in the dissemination of the CTX-M genes and revealed that additional resistance determinants for non-beta-lactam antibiotics were carried by plasmids encoding certain ESBL genes. Results of this study provide an example of how ESBL genes, particularly those of CTX-M lineages, are rapidly spreading among E. coli isolates from commercial pig farms in Sichuan province of China.
authors.affiliation: Bioengineering Research Center for Animal Disease Prevention and Control, Sichuan University, Chengdu, P.R. China.
authors.forename: Guo-Bao
authors.initials: GB
authors.lastname: Tian
authors.forename: Hong-Ning
authors.initials: HN
authors.lastname: Wang
authors.forename: Li-Kou
authors.initials: LK
authors.lastname: Zou
authors.forename: Jun-Ni
authors.initials: JN
authors.lastname: Tang
authors.forename: Ying-Wang
authors.initials: YW
authors.lastname: Zhao
authors.forename: Man-Yu
authors.initials: MY
authors.lastname: Ye
authors.forename: Jing-Yuan
authors.initials: JY
authors.lastname: Tang
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: An-Yun
authors.initials: AY
authors.lastname: Zhang
authors.forename: Xin
authors.initials: X
authors.lastname: Yang
authors.forename: Chang-Wen
authors.initials: CW
authors.lastname: Xu
authors.forename: Yue-Jun
authors.initials: YJ
authors.lastname: Fu
mesh_terms: D000383:Agriculture; D000818:Animals; D001483:Base Sequence; D002681:China; D003227:Conjugation, Genetic; D004269:DNA, Bacterial / Q000032:analysis; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D029968:Escherichia coli Proteins / Q000032:analysis* / Q000235:genetics; D005243:Feces / Q000382:microbiology*; D010957:Plasmids / Q000235:genetics; D016133:Polymerase Chain Reaction; D013552:Swine / Q000382:microbiology*; D018440:beta-Lactam Resistance / Q000235:genetics; D001618:beta-Lactamases / Q000032:analysis* / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; C473109:beta-lactamase CTX-M-15; C062760:beta-lactamase SHV-2; D001618:beta-Lactamases; C542394:beta-lactamase CTX-M-22, E coli