title: Mechanisms of quinolone resistance inEscherichia coliisolated from companion animals, pet-owners, and non-pet-owners.
abstract: The present study investigated the prevalence and mechanisms of fluoroquinolone (FQ)/quinolone (Q) resistance inEscherichia(E.)coliisolates from companion animals, pet-owners, and non-pet-owners. A total of 63E. coliisolates were collected from 104 anal swab samples, and 27 nalidixic acid (NA)-resistant isolates were identified. Of those, 10 showed ciprofloxacin (CIP) resistance. A plasmid-mediated Q resistance gene was detected in one isolate. Increased efflux pump activity, as measured by organic solvent tolerance assay, was detected in 18 NA-resistant isolates (66.7%), but was not correlated with an increase in minimum inhibitory concentration (MIC). Target gene mutations in Q resistance-determining regions (QRDRs) were the main cause of (FQ)Q resistance inE. coli.Point mutations in QRDRs were detected in all NA-resistant isolates, and the number of mutations was strongly correlated with increased MIC (R= 0.878 for NA and 0.954 for CIP). All CIP-resistant isolates (n = 10) had double mutations in thegyrAgene, with additional mutations inparCandparE. Interestingly, (FQ)Q resistance mechanisms in isolates from companion animals were the same as those in humans. Therefore, prudent use of (FQ)Q in veterinary medicine is warranted to prevent the dissemination of (FQ)Q-resistant bacteria from animals to humans.
authors.affiliation: Department of Veterinary Microbiology, College of Veterinary Medicine, BK21 Plus Program for Veterinary Science and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Korea.
authors.forename: Yeon Soo
authors.initials: YS
authors.lastname: Chung
authors.affiliation: Department of Veterinary Microbiology, College of Veterinary Medicine, BK21 Plus Program for Veterinary Science and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Korea.
authors.forename: Yoon Sung
authors.initials: YS
authors.lastname: Hu
authors.affiliation: Department of Veterinary Microbiology, College of Veterinary Medicine, BK21 Plus Program for Veterinary Science and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Korea.
authors.forename: Sook
authors.initials: S
authors.lastname: Shin
authors.affiliation: Animal and Plant Quarantine Agency, Gimcheon 39660, Korea.
authors.forename: Suk Kyung
authors.initials: SK
authors.lastname: Lim
authors.affiliation: Department of Animal Science and Technology, College of Biotechnology and Natural Resource, Chung-Ang University, Anseong 06974, Korea.
authors.forename: Soo Jin
authors.initials: SJ
authors.lastname: Yang
authors.affiliation: Department of Veterinary Microbiology, College of Veterinary Medicine, BK21 Plus Program for Veterinary Science and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Korea.
authors.forename: Yong Ho
authors.initials: YH
authors.lastname: Park
authors.affiliation: Department of Veterinary Microbiology, College of Veterinary Medicine, BK21 Plus Program for Veterinary Science and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Korea.
authors.forename: Kun Taek
authors.initials: KT
authors.lastname: Park
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial / Q000235:genetics / Q000502:physiology*; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D009268:Nalidixic Acid / Q000494:pharmacology*; D010067:Ownership; D057805:Pets / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D009268:Nalidixic Acid
keywords: Escherichia coli; antimicrobial drug resistance; fluoroquinolones; pets; quinolones