Houseflies buzzing around fast-food restaurants could be spreading antibiotic-resistant bacteria, a study of fly-borne microbes suggests.
Although researchers know that drug-resistant microbes develop and are concentrated in places such as hospitals and livestock and poultry farms, it’s unclear how these bacteria spread beyond those places.
Suspecting that houseflies might be transporting the bugs, Ludek Zurek and Lilia Macovei of Kansas State University in Manhattan trapped flies in five fast-food restaurants in northeastern Kansas. The researchers isolated from the flies bacteria called enterococci, which are known to readily transmit antibiotic-resistance genes from one strain of bacteria to another.
Tests showed that the majority of the bacteria from the flies were resistant to at least one common antibiotic, such as tetracycline, streptomycin, or ciprofloxacin. A significant portion of the hardy microbes were resistant to several of the drugs. The researchers report their findings in the June Applied and Environmental Microbiology.
Zurek notes that the presence of antibiotic-resistant enterococci suggests that the flies grew up in agricultural manure, much of which is laden with enterococci. As suburban areas continue to sprawl into rural lands, more flies might carry antibiotic-resistant bugs away from farms to homes and businesses, he adds.
