Elevated Risk of Carrying Gentamicin-Resistant Escherichia coli among U.S. Poultry Workers

The Johns Hopkins University School of Medicine, Baltimore, MD 21224-2780, USA.
Environmental Health Perspectives (Impact Factor: 7.98). 01/2008; 115(12):1738-42. DOI: 10.1289/ehp.10191
Source: PubMed


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.
Our objective was to measure the relative risk for colonization with antimicrobial-resistant Escherichia coli among poultry workers compared with community referents.
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.
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.
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.

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    • "In addition to natural selection and horizontal gene transfer as mechanisms for resistance, sublethal bactericidal antibiotic use at doses below those expected to provide overt selective pressure induces mutations in bacterial genomes that may confer antibiotic resistance (Kohanski et al. 2010). Humans are exposed to anti biotic-resistant bacteria through many pathways, including direct animal contact (Price et al. 2007a), contact with environmental media, such as soil, water, and air, contaminated with animal waste (Graham et al. 2009), and consumption or handling of contaminated food products from animals raised with antibiotics (FDA 2010e; Johnson et al. 2009). Use of medicated feed has been demonstrated to introduce residual antimicrobials and their metabolites into the waste streams of animal operations. "
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