MRSA Found Among Workers At Industrial Farms Using Antibiotics

Researchers have found antibiotic-resistant, infection-causing germs on the bodies of workers at industrial farms that give their livestock antibiotics at nearly twice the rate of workers at farms that do not give their animals antibiotics.  

A study published last month in the medical journal PLOS One looks at workers on industrial farms, checking them for colonies of antibiotic-resistant bacteria that may have developed due to the heavy use of antibiotics in livestock.

The study comes amid an ongoing controversy over antibiotic use, due to fears that excessive and unfocused use of antibiotics will lead to dangerous bacteria developing a defense. A bill is currently being considered in the U.S. Senate that would restrict antibiotic use in livestock.

Johns Hopkins researchers swabbed the noses of workers and their household members at industrial livestock operations and workers at antibiotic-free livestock operations. About 37% of industrial workers at operations that gave livestock antibiotics and their household members had colonies of methicillin-resistant staphylococcus aureus (MRSA). Only 19% of workers at sites that did not use antibiotics had MRSA colonies.

The researchers concluded that the most telling findings were that they only found MRSA associated with livestock among industrial livestock operation workers where antibiotics were used. They also found colonies of multidrug-resistant Staphylococcus aureus (MDRSA), but only among workers at sites that gave livestock antibiotics.

“These findings support growing concern about antibiotics use and confinement in livestock production,” the researchers concluded, “raising questions about the potential for occupational exposure to an opportunistic and drug-resistant pathogen, which in other settings including hospitals and the community is of broad public health importance.”

MRSA infections, which are resistant to treatment by penicillin-based antibiotics, have accounted for more than 60 percent of hospital staph infections in recent years.

The U.S. Centers for Disease Control and Prevention report that about 126,000 hospital MRSA infections occur each year, resulting in about 5,000 deaths. However, some researchers suggest that the number of deaths from MRSA in the U.S. is closer to 20,000 annually.

The workers, while they had colonies of MRSA in their noses, were not suffering from MRSA infections. Many people carry MRSA colonies, but only get infected if the bacteria has access to their bloodstream, typically through a cut or wound.