How did that MRSA get on my shopping cart?

Science Journal Nature Sounds the Alarm On Antibiotic Resistant Bacteria Coming from Feedlots


Science journals typically report emerging scientific research without getting into a lot of advocacy.  But the prestigious journal Nature stepped out of that role this week to call for more advocacy from the science community to stop this threat.

“In the fight to combat antibiotic resistance, researchers should strengthen their advocacy,”  an editorial opines.

An accompanying article reviews recent research linking antibiotic resistant staph infections, including MRSA, between feedlots and people.   About 80% of all antibiotics sold in the US are sold for animal use, mostly to speed animal growth and help the animals survive crowded, stressful and unsanitary feedlot conditions.  A large and well-established scientific literature has shown that this practice breeds antibiotic resistant bacteria that can escape from the feedlot and threaten people. 

MRSA is one of the better known killers in the microbial world, infecting about 94,000 people in the U.S. and killing 18,000, according the article.   Different strains of MRSA are believed to originate in hospitals, communities and feedlots, with the hospital variety causing most of the fatalities.  In Europe, where MRSA infections are tested to identify the strain, researchers have documented the spread from feedlots to humans, although infection of the livestock-originating strains have been mild. Unfortunately, the U.S. lacks such a surveillance system, so we know less about how these bugs might be moving from feedlots to people and back:

“’No one has even looked at these strains in the United States,’ says [researcher Tara Smith, epidemiologist at Iowa State University]. Doctors, she says, often don't determine what strain of MRSA is causing an infection, so it is possible that the bug has been stealthily migrating between farms and hospitals for years.”

On the brighter side, Nature reports a “notable rise in awareness among policy-makers and the public” around this issue and credits academic researchers like Tara Smith for filling in some of the gaping holes in our national health surveillance system. 

I hope this is true.  Meanwhile, wash your hands after you go shopping.  Dr. Smith found (in data not yet officially published) antibiotic resistant staph and MRSA on retail fresh meats and on 5% of the shopping carts she swabbed in Iowa City.