A recent study conducted by researchers at Penn State found that the environment can largely influence the Wolbachia bacteria's ability to inhibit the transmission of the malaria virus to mosquitoes.
The researchers examined the Plasmodium Yoelii malaria parasite and a group of Anopheles stephensi mosquitoes, the mosquitoes most responsible for malaria transmission worldwide, and studied if the Wolbachia bacteria had an effect on malaria transmission at various temperatures. The team tested the relationship between the bacteria and transmission at 68, 72, 75, 79 and 82 degrees Fahrenheit to replicate real-life conditions.
The research team found that at 82 degrees Fahrenheit, the bacteria reduced the rate of transmission to the mosquitoes, but no relationship was observed at any other temperature. The researchers did, however, find that the presence of the Wolbachia bacteria reduced the number of sporozoites, regardless of the temperature, hinting towards a novel relationship between the bacteria and malaria virus.
"Typically, the more oocysts a mosquito has on its midgut, the more sporozoites it produces," Courtney Murdock of Penn State said. "So, depending on the environmental temperature, Wolbachia either reduced, enhanced or had no effect on the number of oocysts. At 75 degrees Fahrenheit, Wolbachia-infected mosquitos had three times the numbers of oocysts relative to uninfected mosquitoes. Thus, we would predict these mosquitoes to produce more sporozoites. But instead we see that this is not the case, and that is because Wolbachia infection significantly reduces the number of sporozoites produced per oocyst regardless of the environmental temperature."
The researchers plan to continue their studies to determine how Wolbachia is influenced by the environment and if it can be used in the development of an anti-malarial substance.