Document Type

Journal Article

Publication Date



Environmental Health Perspectives


Volume 122, Issue 5

Inclusive Pages



Background: Use of antimicrobials in industrial food-animal production is associated with the presence of antimicrobial resistant Staphylococcus aureus among animals and humans. Hog slaughter/processing plants process large numbers of animals from industrial animal operations, and are environments conducive to the exchange of bacteria between animals and workers.

Objectives: To compare the prevalence of methicillin-resistant S. aureus (MRSA) and multidrug resistant S. aureus(MDRSA) carriage between processing plant workers, their household members, and community residents.

Methods: We conducted a cross-sectional study of hog slaughter/processing plant workers, their household members, and community residents in North Carolina. Participants responded to a questionnaire and provided a nasal swab. Swabs were tested for S. aureus, and isolates tested for antimicrobial susceptibility and subjected to multilocus sequence typing.

Results: The prevalence of S. aureus was 21.6%, 30.2%, and 22.5% among 162 workers, 63 household members, and 111 community residents, respectively. The overall prevalence of MRSA and MDRSA tested by disk diffusion was 4.8% and 6.9%, respectively. The adjusted prevalence of MDRSA among workers was 1.96 times (95% CI: 0.71, 5.45) the prevalence in community residents. The adjusted average number of antimicrobial classes to which S. aureus isolates from workers were resistant was 2.54 times (95% CI: 1.16, 5.56) the number among isolates from community residents. One MRSA isolate and two MDRSA isolates from workers were identified as sequence type 398, a type associated with exposure to livestock.

Conclusions: Although the prevalence of S. aureus and MRSA was similar in hog slaughter/processing plant workers and their household and community members, S. aureus isolates from workers were resistant to a greater number of antimicrobial classes. These findings may be related to the non-therapeutic use of antimicrobials in food-animal production.


EHP is a publication of the U.S. Government. Publication of EHP lies in the public domain and is therefore without copyright.

Creative Commons License

Creative Commons License
This work is free of known copyright restrictions.

Peer Reviewed


Open Access