Rising fluoroquinolone resistance in Campylobacter isolated from feedlot cattle in the United States

Authors

Yizhi Tang, Iowa State University
Orhan Sahin, Iowa State UniversityFollow
Nada Pavlovic, Iowa State UniversityFollow
Jeff LeJeune, Ohio State UniversityFollow
James C. Carlson, USDA National Wildlife Research CenterFollow
Zuowei Wu, Iowa State UniversityFollow
Lei Dai, Iowa State UniversityFollow
Qijing Zhang, Iowa State UniversityFollow

Date of this Version

2017

Citation

Scientific Reports | 7: 494 | DOI:10.1038/s41598-017-00584-z 1.

Comments

This work is licensed under a Creative Commons Attribution 4.0 International License.

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 (FQ^R) C. coli isolates examined in this study harbored the single Thr-86-Ile mutation in GyrA, FQ^R C. jejuni isolates had other mutations in GyrA in addition to the Thr-86-Ile change. Notably, most of the analyzed FQ^R C. 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 FQ^R C. coli but not C. jejuni. These findings reveal the rising prevalence of FQ^R Campylobacter in the U.S. and provide novel information on the epidemiology of antibiotic-resistant Campylobacter in the ruminant reservoir.