WILD FLORIDA HOUSE FLIES (MUSCA DOMESTICA) AS CARRIERS OF PATHOGENIC BACTERIA

Bacteria carried by wild house flies (Musca domestica L.) collected near the rear entrances and dumpsters of 4 restaurants in north central Florida were identified. Live house flies were collected and individually transferred to blood agar plates for 1 h. After removing the flies, the plates were incubated overnight at 37(sic)C. Bacterial colonies that were morphologically distinct were isolated from other colonies by streaking onto new plates. The bacteria were identified by fatty acid analysis and sequence of their 16S rRNA gene. The bacterial isolates included 5 new bacterial records for house flies: Acinetobacter baumanni, Bacillus pumilus, Cronobacter sakazakii, Methylobacterium persicinum, and Staphylococcus sciuri. Other bacteria identified have been associated previously with house flies, including Bacillus cereus, B. thuringiensis, Escherichia coli 0157:H7, Shigella dysenteriae, Staphylococcus saprophyticus, and Staphylococcus xylosus. Most of the organisms recovered from the house fly are serious pathogens, known to produce diseases such as meningitis, food poisoning, diarrhea, abscesses, bloodstream infections, and hemorrhagic colitis. The possible exception is Bacillus thuringiensis, a known pathogen for insects that only occasionally produces allergic reactions in humans. If these organisms are not prevented from entering the food preparation and consumption areas, they could become a serious risk in the transmission of diseases.