Describing the impact of daily exposure to tetracycline by dairy cattle hoof trimmers of the Upper Midwest on the prevalence of multidrug resistant Staphylococcus aureus.


Team: Moe, D., Cramer, G., Sreevatsan, S.

Funding Source: UMASH

Project Time Frame: 2016-2017

Multidrug resistant Staphylococcus aureus can cause bacterial infections that can lead to serious illnesses in humans. Certain occupations such as veterinarians and livestock workers are at an increased risk of infection with methicillin susceptible SA (MSSA) and methicillin resistant SA (MRSA) due to their exposure to animals that carry these organisms as “normal” microflora. One population of livestock workers that has not previously been studied are dairy cattle hoof trimmers (HT). Hoof trimmers work on a variety of farms and are exposed daily to topical antibiotics. This project proposes to describe the colonization prevalence of HT with MRSA or other drug-resistant MSSA strains. Fifty HT from the Upper Midwest will be recruited to participate and have nasal swabs collected. In addition, HT will be asked to fill out a descriptive risk factor survey. Nasal swabs will be cultured and have their mean inhibitory concentration to common antibiotics, including different tetracycline types, determined by the MN Department of Health. Once samples have been identified as SA they will undergo further testing including: multi-locus sequence typing and spa-typing. The results from this testing will give us the MSSA and MRSA prevalence, the mecA and the specific SPA type of MRSA positive samples and also the resistance patterns that are most prevalent in HT. The knowledge from this project will guide both physicians and public health officials in treating and tracing SA infections in agricultural communities. In addition, the dairy industry will benefit from the development of health and safety protocols for workers.