The persistence of fluoroquinolone-resistant Campylobacter in poultry production.

BACKGROUND: The use of antibiotics in food animal production has been associated with antibiotic-resistant infections in humans. In 2005, the Food and Drug Administration (FDA) banned fluoroquinolone use in U.S. poultry production in order to reduce the prevalence of fluoroquinolone-resistant Campylobacter. Little is known about the potential efficacy of this policy. OBJECTIVES: Our primary objective was to follow temporal changes in the prevalence of fluoroquinolone-resistant Campylobacter among poultry products from two conventional producers who announced their cessation of fluoroquinolone use in 2002 (3 years before the FDA's ban). Our secondary objective was to compare, over time, the prevalence of fluoroquinolone-resistant Campylobacter in conventional poultry products to those from producers who claim to use no antibiotics. METHODS: We collected poultry samples from two conventional producers and three antibiotic-free producers over the course of 20 weeks in 2004 (n = 198) and 15 weeks in 2006 (n = 210). We compared the rates of fluoroquinolone resistance among Campylobacter isolates from the different producers. RESULTS: We found no significant change in the proportion of fluoroquinolone-resistant Campylobacter isolates from the two conventional producers over the study period. In addition, Campylobacter strains from the two conventional producers were significantly more likely to be fluoroquinolone resistant than those from the antibiotic-free producers. CONCLUSIONS: The results from this study indicate that fluoroquinolone-resistant Campylobacter may be persistent contaminants of poultry products even after on-farm fluoroquinolone use has ceased. The FDA's ban on fluoroquinolones in poultry production may be insufficient to reduce resistant Campylobacter in poultry products.

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

BACKGROUND: Antimicrobial 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. OBJECTIVE: Our objective was to measure the relative risk for colonization with antimicrobial-resistant Escherichia coli among poultry workers compared with community referents. METHODS: We 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. RESULTS: Poultry 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. CONCLUSIONS: Occupational 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.

Neurologic symptoms and neuropathologic antibodies in poultry workers exposed to Campylobacter jejuni.

OBJECTIVES: To examine associations between occupational exposure to live poultry with Campylobacter exposure, Campylobacter-associated neurologic symptoms, and neuropathologic antibodies. METHODS: Questionnaires, serum samples, and stool specimens were collected from 20 poultry workers and 40 community referents. Campylobacter exposure was evaluated by stool culture and serum antibodies; neurologic symptoms were assessed by questionnaire; and neuropathologic antibodies were measured by serum anti-glycolipid antibody concentrations. RESULTS: Poultry workers had significantly higher anti-Campylobacter immunoglobulin G titers compared with that of referents (P < 0.05); they were significantly more likely to report multiple Campylobacter-associated neurologic symptoms; and male poultry workers had a higher point risk estimate for detectable neuropathologic anti-glycolipid immunoglobulin G titers (P = 0.07) compared with male referents. CONCLUSIONS: These data suggest that poultry workers are at elevated risk of Campylobacter exposure and may be at elevated risk for Campylobacter-associated neurologic sequelae.

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.