Every year, more than 500,000 people are killed by malaria parasite, most of them youngsters under the age of five. However, there are numerous obstacles to overcome in disease control strategies: Insecticide-resistant mosquitoes emerge, and vaccinations only offer a partial defense. A naturally occurring bacterium that, when fed to mosquitoes, stops the development of the malaria parasite in the insects’ bellies, according to researchers, has been identified as a new weapon.
According to Carolina Barillas-Mury, director of the malaria and vector research lab at the U.S. National Institutes of Health, the findings provide an addition to current malaria prevention strategies. According to Barillas-Mury, who was not engaged in the investigation, the strategy “has great potential to be implemented” in regions where malaria is an endemic disease.
Utilize microbes to control diseases
Before, scientists attempted to utilize microbes to control diseases spread by mosquitoes. Recent clinical trials using the virus-fighting bacterium Wolbachia pipientis against dengue fever have shown significant promise, and it is now being utilized in several parts of the world. However, the majority of strategies for preventing the Plasmodium parasites that cause malaria and are spread by distinct mosquito species from those that cause dengue have depended on genetically modified bacteria. Given the risks associated with releasing altered organisms into the wild, Barillas-Mury cites this as a significant barrier to regulatory and public approval.
Without human genetic manipulation, the bacterium in the current discovery, which was reported today in Science, blocks the malaria parasite. At a GSK research facility in Spain, Janneth Rodrigues, a scientific lead in global health medicines R&D, and colleagues discovered the bacterium after finding that the mosquitoes they were using for malaria research were becoming more difficult to infect with Plasmodium.
Delftia tsuruhatensis TC1 bacteria, an unexpected microorganism, was found inside the intestines of these mosquitoes, according to Rodrigues. Although the species has previously been found in the intestines of several insects, as well as in water, soil, and sporadically in hospital-acquired diseases, it is unclear how the bug ended up there.
Rodrigues’ team collaborated with Marcelo Jacobs-Lorena, a malaria parasite researcher at the Johns Hopkins Bloomberg School of Public Health, to gain further knowledge. In his laboratory, it was found that D. tsuruhatensis was preventing Plasmodium from developing in the mosquito’s gut, where it first appears, before moving on to the insect’s salivary glands. Insects with D. tsuruhatensis had roughly 75% fewer Plasmodium oocysts—egg-like structures the parasite develops in the insect gut than mosquitoes lacking the bacteria.