title: Rising fluoroquinolone resistance in Campylobacter isolated from feedlot cattle in the United States.
abstract: Antibiotic resistance, particularly to fluoroquinolones and macrolides, in the major foodborne pathogen Campylobacter is considered a serious threat to public health. Although ruminant animals serve as a significant reservoir for Campylobacter, limited information is available on antibiotic-resistant Campylobacter of bovine origin. Here, we analyzed the antimicrobial susceptibilities of 320 C. jejuni and 115 C. coli isolates obtained from feedlot cattle farms in multiple states in the U.S. The results indicate that fluoroquinolone resistance reached to 35.4% in C. jejuni and 74.4% in C. coli, which are significantly higher than those previously reported in the U.S. While all fluoroquinolone resistant (FQR) C. coli isolates examined in this study harbored the single Thr-86-Ile mutation in GyrA, FQRC. jejuni isolates had other mutations in GyrA in addition to the Thr-86-Ile change. Notably, most of the analyzed FQRC. coli isolates had similar PFGE (pulsed field gel electrophoresis) patterns and the same MLST (multilocus sequence typing) sequence type (ST-1068) regardless of their geographic sources and time of isolation, while the analyzed C. jejuni isolates were genetically diverse, suggesting that clonal expansion is involved in dissemination of FQRC. coli but not C. jejuni. These findings reveal the rising prevalence of FQRCampylobacter in the U.S. and provide novel information on the epidemiology of antibiotic-resistant Campylobacter in the ruminant reservoir.
authors.affiliation: Department of Veterinary Microbiology and Preventive Medicine, Ames, IA, USA.
authors.forename: Yizhi
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Department of Veterinary Microbiology and Preventive Medicine, Ames, IA, USA. osahin@iastate.edu.|Department of Veterinary Diagnostic and Production Animal Medicine, Ames, IA, USA. osahin@iastate.edu.
authors.forename: Orhan
authors.initials: O
authors.lastname: Sahin
authors.affiliation: Department of Veterinary Microbiology and Preventive Medicine, Ames, IA, USA.
authors.forename: Nada
authors.initials: N
authors.lastname: Pavlovic
authors.affiliation: Food Animal Health Research Program, Ohio State University, Wooster, OH, USA.
authors.forename: Jeff
authors.initials: J
authors.lastname: LeJeune
authors.affiliation: National Wildlife Research Center, USDA APHIS, Fort Collins, CO, USA.
authors.forename: James
authors.initials: J
authors.lastname: Carlson
authors.affiliation: Department of Veterinary Microbiology and Preventive Medicine, Ames, IA, USA.
authors.forename: Zuowei
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Department of Veterinary Microbiology and Preventive Medicine, Ames, IA, USA.
authors.forename: Lei
authors.initials: L
authors.lastname: Dai
authors.affiliation: Department of Veterinary Microbiology and Preventive Medicine, Ames, IA, USA. zhang123@iastate.edu.
authors.forename: Qijing
authors.initials: Q
authors.lastname: Zhang
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002167:Campylobacter / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D002169:Campylobacter Infections / Q000662:veterinary*; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000382:microbiology*; D016000:Cluster Analysis; D024881:Drug Resistance, Bacterial; D024901:Drug Resistance, Multiple, Bacterial; D024841:Fluoroquinolones / Q000494:pharmacology*; D014644:Genetic Variation; D008826:Microbial Sensitivity Tests; D015995:Prevalence; D014481:United States / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones