By genetically modifying bacteria that they found to be uniquely associated with disease-carrying mosquitoes, scientists hope to create a new weapon to prevent transmission of malaria.

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Scientists are investigating how to genetically modify a new family of bacteria found in mosquitoes to prevent spread of the malaria parasite.

The scientists, from Sweden, Germany and Austria, recently published a paper in the International Journal of Systematic and Evolutionary Microbiology.

In that paper, they describe genetic and other test results to show they have found two new strains or species of the bacterial genus Thorsellia: Thorsellia kenyensis and Thorsellia kandunguensis.

The team isolated the bacterial strains from larvae of the mosquito Anopheles arabiensis, one of the most important spreaders of malaria in sub-Saharan Africa and surrounding areas.

They are now looking for a way to use the bacteria in the fight against malaria.

Thorsellia, and the family the genus belongs to – Thorselliaceae – are named after the pioneering mosquito researcher Professor Walborg Thorsell – now 96 years old – who started investigating mosquitoes in the 1970s and then moved into developing mosquito repellents for soldiers to use in war zones.

One of the study investigators, Olle Terenius, a researcher in the Department of Ecology at the Swedish University of Agricultural Sciences (SLU) in Uppsala, says:

“When we discovered the first species of Thorsellia in a Kenyan malaria mosquito and decided to name the unique bacterium after Thorsell, we did not know that it would prove to be so common in mosquitoes.”

Since first discovering Thorsellia bacteria in Kenyan malaria mosquitoes, the scientists have also isolated strains from mosquitoes spreading malaria in Africa, Brazil, India and Iran, and in mosquitoes spreading West Nile virus in the US.

It is unusual to find a new family of bacteria in this part of the family tree – it has only happened once before in the last 50 years.

From what they have learned, the team believes that Thorsellia bacteria have been evolving alongside disease-carrying mosquitoes for a very long time, during which they have developed properties that help them survive in the mosquitoes.

Terenius says they are excited by the fact they have only found these bacteria in disease-carrying mosquitoes and the waters their larvae hatch in, and adds:

“We and other research groups are now trying to understand the interaction between Thorsellia and mosquitoes. Among other things, Thorsellia have properties facilitating mosquito-larvae uptake and survival.”

Co-author Sebastian Håkansson, a researcher at SLU’s Department of Microbiology, explains they are now investigating ways in which they could use the bacteria to fight malaria:

We are looking for bacteria that live in the mosquito gut and which grow quickly when the mosquito has taken a blood meal. The idea is to genetically modify these bacteria to produce substances that stop malaria parasite development.”

He also notes that by using bacteria closely linked to malaria mosquitoes, they reduce the risk that genetically modified bacteria end up in the wrong place in nature.

Meanwhile, Medical News Today recently learned how a team of scientists is developing a way to use satellite data to fight malaria and other parasitic diseases. They are combining health data with satellite-acquired data on climate and terrain to make a geographical information system that helps decision makers quickly locate high-risk disease areas, and see whether there is enough resource there.