In a groundbreaking study, researchers have successfully engineered human skin bacteria to significantly reduce mosquito attraction, offering protection for up to 11 days. This innovative approach presents a potential game-changer in the fight against mosquito-borne diseases such as malaria, West Nile, dengue, yellow fever, and Zika. Findings from the new study were published recently in PNAS Nexus.

The team, led by Dr. Omar Akbari at UCSD, focused on modifying common human skin commensals, specifically Staphylococcus epidermidis and Corynebacterium amycolatum. By reducing the production of a form of lactic acid known to attract mosquitoes, they aimed to create a living, long-lasting mosquito repellent.

"Female mosquitoes are highly attuned to the scents released by skin microbes on their targets," the study authors noted. "Our engineered bacteria significantly reduce these attractive cues, providing a novel approach to mosquito repellency."

Engineered Bacteria Show Promising Results

The study's findings are compelling. When tested in isolation, the engineered version of S. epidermidis attracted about half as many Aedes aegypti and Anopheles gambiae mosquitoes compared to their wild-type counterparts. Culex quinquefasciatus mosquitoes were also 22% less attracted to the engineered microbes.

Further trials involved applying the engineered microbes to mice. The results were striking: mice treated with wild-type S. epidermidis attracted a significant number of mosquitoes, while those painted with the engineered bacteria saw a reduction in mosquito attraction by up to 64.4%. This repellent effect lasted for an impressive 11 days, far surpassing the several hours of protection offered by conventional chemical repellents such as N,N-diethyl-meta-toluamide (DEET).

"Engraftment of these engineered bacteria onto the skin of mice reduced mosquito attraction and feeding for up to 11 uninterrupted days," the study authors remarked. "This duration is considerably longer than the protection conferred by the leading chemical repellent DEET."

A Potential New Class of Mosquito Repellent

The study, detailed in the team's recent publication, emphasizes the feasibility of creating a microbiome-based mosquito repellent that could provide long-lasting protection. The significance of this discovery is underscored by the urgent need for effective mosquito control measures to combat the spread of deadly diseases.

"The human scent is derived from the metabolism of the human skin microbiota," remarked the study authors. "By knocking out the synthesis of key mosquito attractants, we pave the way for the development of a skin therapy that offers more permanent protection against mosquito-borne diseases."

Implications for Future Research and Development

These findings open the door to further exploration and potential commercialization of microbiome-based mosquito repellents. The innovative approach could revolutionize how we protect ourselves from mosquito bites and the diseases they carry.

"Our findings demonstrate that engineering the skin microbiome to reduce attractive volatiles represents an untapped strategy to reduce vector attraction, preventing bites and pathogen transmission," the study authors emphasized. "This sets the stage for new classes of long-lasting microbiome-based repellent products."

As researchers continue to build on these promising results, the hope is that genetically engineered skin bacteria could soon offer a more effective and enduring solution to one of the world's most pressing public health challenges.