There may soon be a non-toxic, longer-acting and less odorous alternative to DEET to repel mosquitoes. Scientists have created genetically modified human skin bacteria that are completely unattractive to the irritating, disease-spreading insects.
Female blood-sucking mosquitoes are attracted to humans and other animals by exhaled carbon dioxide, body heat, and compounds produced by harmless bacteria that are part of our skin's microbiome (the community of naturally occurring microbes). CO2 and heat, directly Although mosquitoes come towards us, the bacterial scents found in the substrates lead them directly to our skin.
Two types of bacteria – Staphylococcus epidermidis And Corynebacterium amycolatum – make up most of the microbiome. They also produce L-(+)-lactic acid, a type of lactic acid that is known to attract mosquitoes.
A team of US scientists led by Prof. Omar Akbari of the University of California-San Diego recently created versions of two bacteria that were genetically engineered to lack the gene responsible for producing the acid. The idea was that if these modified bacteria were introduced into an existing microbiome, they would largely displace existing natural forms. S. epidermidis And C. amycolatum.
In laboratory tests, shaved patches on live mice were stained with natural or engineered forms of two bacteria. Over the next 14 days, the rodents were Egyptian snake, Anopheles gambia And Pentagonal stemmed plant Get 10 minutes of contact with mosquitoes every day – all three species of mosquito are responsible for spreading diseases such as malaria and dengue fever.
Three days after application, the engineered product S. epidermidis reduced mosquito attraction by up to 64.4% compared to the natural form of the bacteria. Moreover, the effect lasted for 11 days. Designed C. amycolatum similar results were obtained.
In contrast, the repellent effect of DEET usually only lasts for four to eight hours. However, DEET has a More strong The effect is unchanged, but this may change as the bacterial repellent is further developed.
An article about the research, in which scientists from Stanford University also participated, was recently published in the journal PNAS Link.
Source: PNAS via EurekAlert