Food & Nutrition
Houseflies Collected in Fast Food Restaurants Found to Carry Antibiotic Resistant Bacteria
By American Society for Microbiology
Jun 15, 2006, 18:01

Houseflies in food-handling and serving facilities carry and may have the capacity to transfer antibiotic-resistant and potentially virulent bacteria say researchers Kansas State University. They report their findings in the June 2006 issue of the journal Applied and Environmental Microbiology.

Multi-drug resistance is a serious problem plaguing the world today as the number of antibiotics effective at treating human infections continues to decline. Although it is not yet well understood, preliminary research has indicated a connection between antibiotic resistance and food of animal origin. Experts are now examining the role that insects that develop in decaying organic material (specifically manure) may play in transmitting antibiotic resistant bacteria to residential settings.

Enterococci are commonly found in animal and human digestive tracts and are known for their frequent multi-antibiotic resistance. Two of the 26 species, Enterococcus faecalis and Enterococcus faecium are responsible for the majority of human infections. In the study the digestive tracts of 260 houseflies collected from five fast food restaurants were tested for enteroccoci and characterized. Ninety-seven percent tested positive for the bacteria with E. faecalis identified in the majority of the isolates (88.2%). E. faecalis was found to carry virulence genes and have varying percentages of resistance to tetracycline, erythromycin, streptomycin, ciproflaxin and kanamycin. E. faecium showed up at a rate of 6.8%.

"This study showed that houseflies in food-handling and serving facilities carry antibiotic-resistant and potentially virulent enterococci that have the capacity for horizontal transfer of antibiotic resistance genes to other bacteria," say the researchers.

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