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This is Scientific American's 60-Second Science. I'm Cynthia Graber. This will just take a minute.

Seventy percent of all antibiotics¹ in this country go to livestock² like pigs and chickens. And concern is growing about drug-resistant bacteria that sprout³ up in crowded livestock facilities and may spread to humans. Now researchers suggest that a vector for that spread may be the common housefly.

Scientists from the Johns Hopkins Bloomberg School of Public Health collected samples of both flies and poultry⁴ litter at chicken houses along the Delmarva Peninsula. That's the region where Delaware, Maryland and Virginia meet up, and it has the highest concentration of what are known as broiler chickens in the U.S.

They isolated⁵ and analyzed⁶ antibiotic-resistant enterococci and staphylococci from both groups. The samples showed that the bacteria in both the flies and the litter have similar characteristics and genes⁷ for resistance. The researchers caution that they haven't shown conclusively⁸ that flies are in fact spreading the diseases. But more than 30,000 flies might enter a poultry house over six weeks. And flies are known to be vectors of viral and bacterial⁹ diseases such as cholera¹⁰. Another study to add to the growing pile of research suggesting our cheap meat is not as cheap as it seems.

Thanks for the minute for Scientific American's 60-Second Science. I'm Cynthia Graber.