It’s never nice to see a fly sit on what you were going to eat. New research has found that you are justified if you want to throw that delicious piece of food (where the fly has been) into the trash.
The new research was published in the journal Scientific Reports and shows that two types of common flies – the housefly and the blowflies – are capable of transporting hundreds of different bacterial species, many of which are dangerous to humans. Since these flies are born from fecal matter and carrion, the findings are not a total surprise. However, it is the first study in which the contents of the intestine are analyzed in detail and also evaluates the ability of the flies to transport and infect germs.
As flies like to be close to humans, unfortunately, these findings are a bit worrisome.
“We believe that this may prove that flies have a mechanism for the transmission of pathogens that has been ignored by health professionals. [Our research shows] that flies may contribute to the rapid transmission of pathogens during epidemic outbreaks, “said Donald Bryant, a co-author of the new study and a professor at the University of Pennsylvania.
To conduct the study, the researchers analyzed the microbiome of 116 houseflies and blowflies from three different continents. In addition to detecting and classifying the different germs in the stomachs of the flies, the scientists also studied the microbial content of insect body parts. They found that the legs are the main vehicle for the transmission of microbial organisms from one surface to another.
“The legs and wings have the highest microbial activity in the body of the fly, which suggests that the bacteria use flies as an air bus,” said Stephan Schuster, a co-author of the study. “It may be that the bacteria survive their journey, growing and spreading on a new surface. In fact, the study shows that with each step (of the hundreds taken by a fly) the insect leaves a microbial state of a colony if the new surface is suitable for the growth of bacteria.
In short: what a disgust. In 15 cases, researchers found traces of the human pathogen Helicobacter pylori – which causes ulcers in the human intestines – in Brazilian blowflies. Before this study, scientists had never considered that flies could be carriers of this disease.
The researchers also learned that the housefly and blowfly are very similar in content of their stomachs. They share more than 50% of their microbiome, a nefarious mixture of microorganisms that the flies take from their surroundings. Interestingly, farm flies had fewer germs than those in urban environments.
“[These findings] will make you think twice before eating that potato salad that has been uncovered on your next picnic,” Bryant said. “It would be better to have a picnic in a forest far away from urban environments and not a central park.”