title: Profiling of antimicrobial resistance and plasmid replicon types in β-lactamase producing Escherichia coli isolated from Korean beef cattle.
abstract: In this study, 78 isolates of Escherichia coli isolated from Korean beef cattle farms were investigated for the production of extended-spectrum β-lactamase (ESBL) and/or AmpC β-lactamase. In the disc diffusion test with ampicillin, amoxicillin, cephalothin, ceftiofur, cefotaxime, ceftazidime, and cefoxitin, 38.5% of the isolates showed resistance to all of ampicillin, amoxicillin, and cephalothin. The double disc synergy method revealed that none of the isolates produced ESBL or AmpC β-lactamases. DNA sequencing showed that all isolates encoded genes for TEM-1-type β-lactamase. Moreover, 78.2% of the isolates transferred the TEM-1-type β-lactamase gene via conjugation. In plasmid replicon typing of all donors, IncFIB and IncFIA were identified in 71.4% and 41.0% of plasmids, respectively. In transconjugants, IncFIB and IncFIA were the most frequent types detected (61.5% and 41.0%, respectively). Overall, the present study indicates that selection pressures of antimicrobials on β-lactamases in beef cattle may be low relative to other livestock animals in Korea. Moreover, to reduce selection pressure and dissemination of β-lactamase, the long-term surveillance of antimicrobial use in domestic beef cattle should be established.
authors.affiliation: Department of Infectious Diseases, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea.
authors.forename: Seung Won
authors.initials: SW
authors.lastname: Shin
authors.affiliation: Department of Infectious Diseases, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea.
authors.forename: Myunghwan
authors.initials: M
authors.lastname: Jung
authors.affiliation: Department of Infectious Diseases, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea.
authors.forename: Min-Kyung
authors.initials: MK
authors.lastname: Shin
authors.affiliation: Department of Infectious Diseases, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea.|Institute of Green Bio Science and Technology, Seoul National University, Pyeungchang 25354, Korea.
authors.forename: Han Sang
authors.initials: HS
authors.lastname: Yoo
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D005243:Feces / Q000382:microbiology; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D012093:Replicon; D056910:Republic of Korea; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D001618:beta-Lactamases
keywords: Escherichia coli; antimicrobial resistance; plasmid replicon typing; β-lactamase