A new study published in Nature has shown that houseflies and blowflies carry many more types of pathogenic bacteria than previously thought. That means if a housefly lands on your food at a picnic, don’t just brush it off. Throw the food away. These bacteria are not only unsafe from a food poisoning perspective, but one found on the flies, Helicobacter pylori, can cause peptic ulcers, increasing the risk of stomach cancer and a type of non-Hodgkin’s lymphoma.
One of the study’s authors, Dr. Donald Bryant from Pennsylvania State University said, “We believe that the study may show a mechanism for pathogen transmission that has been overlooked by public health officials, and flies may contribute to the rapid transmission of pathogens in outbreak situations.”
These insects breed in feces and decaying vegetable and animal matter. There, they pick up pathogenic bacteria and transport them when they fly around.And these insects are the first organisms to arrive on carcasses, where they feed, lay eggs, and breed.
The study founds that the legs and wings have the most bacteria. The study’s other corresponding author, Dr. Stephan Schuster at Nanyang Technological University in Singapore, said, “The legs and wings show the highest microbial diversity in the fly body, suggesting that bacteria use the flies as airborne shuttles. It may be that bacteria survive their journey, growing and spreading on a new surface. In fact, the stud shows that each step of hundred that a fly has taken leads behind a microbial colony track, if the new surface supports bacterial growth.”
The scientists sampled 116 houseflies and blowflies from different habitats on three continents (Brazil, the U.S., and Singapore) in urban, rural, and natural settings. They were subjected to whole-genome shotgun sequencing.Scientists found that blowflies and houseflies share over 50% of their microbiome. They also found that flies collected from stables had fewer pathogens that flies collected from urban areas.
The study found that in densely populated areas, surveillance of the housefly and blowfly is important. This surveillance should be included in public health programs, and it may be “possible to predict and prevent routes of transmission of microbes and potential pathogens.”
