Fluoroquinolone-Resistant Campylobacter Isolates from Conventional and Antibiotic-Free Chicken Products

The use of fluoroquinolones (FQs) in poultry production is an important issue in public health today. In February 2002, two prominent U.S. poultry companies pledged to stop using FQs for flock-wide treatment. One year later, we began a survey of Campylobacter isolates on chicken products from these two companies and from two producers claiming total abstention from antibiotic use. Using both standard isolation methods and new methods modified to enhance detection of FQ-resistant Campylobacter, we compared rates of FQ-resistant Campylobacter among these products. Four major findings were drawn from this study: a) antibiotic-free brands were not more likely to be contaminated with Campylobacter; b) a high percentage of products from the two conventional brands were contaminated with FQ-resistant Campylobacter (43 and 96%); c) these conventional brands had significantly higher odds of carrying resistant strains compared with antibiotic-free products; and d) supplementing media with FQs increased the sensitivity of detecting FQ-resistant strains among mixed populations of Campylobacter, thus reducing a bias toward underestimating the prevalence of FQ-resistant Campylobacter on samples. These results suggest that FQ resistance may persist in the commercial poultry environment in the absence of FQ-selective pressure and that these strains contaminate a larger proportion of foods than reported previously

Elevated risk of carrying gentamicin-resistant Escherichia coli among U.S. poultry workers.

BackgroundAntimicrobial use in food-animal production is an issue of growing concern. The application of antimicrobials for therapy, prophylaxis, and growth promotion in broiler chicken production has been associated with the emergence and dissemination of antimicrobial-resistant enteric bacteria. Although human exposure to antimicrobial-resistant bacteria through food has been examined extensively, little attention has been paid to occupational and environmental pathways of exposure.ObjectiveOur objective was to measure the relative risk for colonization with antimicrobial-resistant Escherichia coli among poultry workers compared with community referents.MethodsWe collected stool samples and health surveys from 16 poultry workers and 33 community referents in the Delmarva region of Maryland and Virginia. E. coli was cultured from stool samples, and susceptibility to ampicillin, ciprofloxacin, ceftriaxone, gentamicin, nitrofurantoin, and tetracycline was determined for each E. coli isolate. We estimated the relative risk for carrying antimicrobial-resistant E. coli among poultry workers compared with community referents.ResultsPoultry workers had 32 times the odds of carrying gentamicin-resistant E. coli compared with community referents. The poultry workers were also at significantly increased risk of carrying multidrug-resistant E. coli.ConclusionsOccupational exposure to antimicrobial-resistant E. coli from live-animal contact in the broiler chicken industry may be an important route of entry for antimicrobial-resistant E. coli into the community