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Hog CAFO Workers Have Higher Incidence of MDRSA Biomarkers

[ Edited ]

Staph that is resistant to multiple drugs is more often found in workers in hog confinement facilities than in operations that don't use drugs, according to a recently released study.

That dosen't mean the workes are any more frequently sick


"Biomarkers for livestock-associated Staphylococcus aureus were more prevalent in workers at industrial livestock operations than in those at antibiotic-free, free-range (AFFR) farms, researchers found"


"Three specific biomarkers in MDRSA and methicillin-resistant S. aureus (MRSA) -- sequence type CC398, lack of the so-called scn genetic element, and tetracycline resistance -- are indicators of livestock-associated bacteria. These may be more prevalent in confined livestock that receive antibiotics for nontherapeutic growth promotion compared with antibiotic-free, pasture-roaming livestock, Heaney and colleagues indicated.

They noted that human infections from livestock-associated S. aureus, especially sequence type CC398, have been rare in the U.S., but several European countries have seen a concerning number of human cases."


"Each S. aureus-positive sample was tested with a panel of 16 different antibiotics from 12 antibiotic classes. Results showed complete or intermediate resistance to all antibiotics except vancomycin, linezolid, and sulfamethoxazole/trimethoprim.

Complete resistance to tetracycline in S. aureus-positive individuals occurred in 2.4% of AFFR samples compared with 46.3% of industrial samples resulting in a prevalence ratio of 19.5 (95% CI 2.7-140.4). Resistance to tetracycline among S. aureus CC398 in both livestock and humans in close contact with livestock has been nearly universal.

The CC398 strain was present in 31.7% of industrial workers, but only 2.4% of AFFR workers. No household members carried the CC398 strain."


""Overall, our findings support growing concern about antibiotic use and confinement in livestock production, and raise questions about the potential for occupational exposure to an opportunistic and drug-resistant pathogen which in other settings including hospitals and the community is a major cause of morbidity and mortality in the U.S. and globally," Heaney and colleagues concluded.

"This study illustrates that humans and animals they are in close contact with exchange bacteria -- a particular concern when the bacteria is multiple-drug resistant," Amesh A. Adalja, MD, of the University of Pittsburgh Medical Center's Center for Health Security, told MedPage Today in an email. "However, it is important to note that prevalence of MRSA was similar in both groups."

The study was funded by the North Carolina Translational and Clinical Sciences Institute, North Carolina Occupational Safety and Health Education and Research Center, W.K. Kellogg Health Scholars Program-Community Track, and UNC Gillings School of Global Public Health.

One author reported providing pro bono consultation on radiation and health as well as expert testimony for two law firms, which made gifts to the University of North Carolina. Other authors had no relevant disclosures."


Here is an MRSA "fast facts" piece: