Skin Microbiome with “Living Repellent” Reduces Mosquito Attraction!

The gold-standard synthetic repellent, N,N-diethyl-m-toluamide (DEET), protects against mosquitoes for just four to eight hours. More lasting protection would be invaluable. Not only would it save us from untold numbers of annoying mosquito bites, but it would also reduce the spread of mosquito-borne diseases such as dengue fever, Zika, and malaria.

Encouragingly, a potential DEET alternative, one that promises more lasting protection, is being developed by scientists at the University of California, San Diego. In tests with mice, this alternative reduced mosquito attraction and feeding for up to 11 uninterrupted days.

What’s the alternative? Genetically engineered versions of the common human skin commensals Staphylococcus epidermidis and Corynebacterium amycolatum. These “living repellents” produce much less l-(+)-lactic acid, a form of lactic acid that is known to attract mosquitoes.

Details about this new means of keeping mosquitoes at bay appeared in the journal PNAS Nexus, in an article titled, “Engineered skin microbiome reduces mosquito attraction to mice.” https://academic.oup.com/pnasnexus/article/3/7/pgae267/7717706?login=false#476174479

“We engineered bacteria by deleting the l-lactate dehydrogenase (Δl-ldh) gene,” the article’s authors wrote. “We also demonstrated that mosquitoes are less attracted to the scent of the Δl-ldh strains than to wild-type in vitro. These findings prove that skin bacterium deprived of the ability to produce l-(+)-lactic acid is key to reducing mosquito attraction, despite these bacteria producing other human skin-derived odorants.”

https://www.genengnews.com/topics/infectious-diseases/skin-microbiome-with-living-repellent-reduces-mosquito-attraction/