[Source: PLoS One, full page: (LINK). Abstract, edited.]
OPEN ACCESS / PEER-REVIEWED / RESEARCH ARTICLE
Identification and Characterization of Cefotaxime Resistant Bacteria in Beef Cattle
Raies A. Mir, Thomas A. Weppelmann, Judith A. Johnson, Douglas Archer, J. Glenn Morris Jr, KwangCheol Casey Jeong
Published: September 19, 2016 / http://dx.doi.org/10.1371/journal.pone.0163279
Third-generation cephalosporins are an important class of antibiotics that are widely used in treatment of serious Gram-negative bacterial infections. In this study, we report the isolation of bacteria resistant to the third-generation cephalosporin cefotaxime from cattle with no previous cefotaxime antibiotic exposure. The prevalence of cefotaxime-resistant bacteria was examined by a combination of culture based and molecular typing methods in beef cattle (n = 1341) from 8 herds located in North Central Florida. The overall prevalence of cefotaxime-resistant bacteria was 15.8% (95% CI: 13.9, 17.8), varied between farms, and ranged from 5.2% to 100%. A subset of isolates (n = 23) was further characterized for the cefotaxime minimum inhibitory concentration (MIC) and antibiotic susceptibility against 10 different antibiotics, sequencing of nine β- lactamase genes, and species identification by 16S rRNA sequencing. Most of the bacterial isolates were resistant to cefotaxime (concentrations, > 64 μg/mL) and showed high levels of multi-drug resistance. Full length 16S rRNA sequences (~1300 bp) revealed that most of the isolates were not primary human or animal pathogens; rather were more typical of commensal, soil, or other environmental origin. Six extended spectrum β-lactamase (ESBL) genes identical to those in clinical human isolates were identified. Our study highlights the potential for carriage of cefotaxime resistance (including “human” ESBL genes) by the bacterial flora of food animals with no history of cefotaxime antibiotic exposure. A better understanding of the origin and transmission of resistance genes in these pre-harvest settings will be critical to development of strategies to prevent the spread of antimicrobial resistant microorganisms to hospitals and communities.
Citation: Mir RA, Weppelmann TA, Johnson JA, Archer D, Morris JG Jr, Jeong KC (2016) Identification and Characterization of Cefotaxime Resistant Bacteria in Beef Cattle. PLoS ONE 11(9): e0163279. doi:10.1371/journal.pone.0163279
Editor: Yung-Fu Chang, Cornell University, UNITED STATES
Received: April 11, 2016; Accepted: September 5, 2016; Published: September 19, 2016
Copyright: © 2016 Mir et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: All relevant data are within the paper.
Funding: This material is based upon work that is supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, under the award number 2015-68003-22971 to KCJ. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
Keywords: Research; Abstracts; Antibiotics; Drugs Resistance; Cefotaxime; Cattle; Food Safety.