Chinese scientists have made a significant breakthrough in the fight against mosquito-borne diseases by altering the gut bacteria of mosquitoes. This innovative approach could become a natural alternative to genetically modified mosquito releases currently used in places like Florida.
Mosquito-borne viruses such as dengue and Zika infect millions annually, posing severe health risks worldwide. Dengue alone affects approximately 390 million people each year.
Over the past decade, frequent dengue outbreaks have been documented in Xishuangbanna and Lincang, both in southwest China’s Yunnan Province, while neighboring cities Wenshan and Pu’er reported few cases. This disparity intrigued researchers from Tsinghua University and the Yunnan Academy of Animal Science and Veterinary Sciences.
By conducting field investigations on thousands of blood-sucking female mosquitoes, the team discovered that mosquitoes from different habitats carry distinct symbiotic bacteria in their guts—the first organ typically infected by viruses.
Among 55 bacterial strains identified, Rosenbergiella_YN46 was abundant in the gut of mosquitoes from Wenshan and Pu’er but scarce in those from Xishuangbanna and Lincang, according to their study published in the journal Science on Friday.
The researchers introduced Rosenbergiella_YN46 into the intestines of two common disease-transmitting mosquito species—Aedes albopictus and Aedes aegypti. The modified mosquitoes showed a reduced likelihood of being infected with dengue and Zika viruses through blood feeding.
Further analysis revealed that an enzyme produced by the bacteria converts glucose into gluconic acid, rapidly acidifying the mosquito’s gut environment. This acidic environment neutralizes mosquito-borne viruses, preventing them from infecting the insect.
To test the practical application of their findings, the team conducted a field experiment in Mengla County, Xishuangbanna. They added Rosenbergiella_YN46 bacteria to the water where mosquito eggs were laid and hatched. The bacteria successfully colonized the mosquito populations, with the modified mosquitoes demonstrating reduced virus transmission capabilities.
Cheng Gong, the corresponding author from Tsinghua University, suggested another potential intervention strategy involving plants. Since mosquitoes acquire gut microbes from breeding waters and plant sap or nectar, introducing plants enriched with Rosenbergiella_YN46 could naturally disseminate the beneficial bacteria.
“We are collecting numerous plant samples in Wenshan, where the bacterium was isolated, to find plants that harbor this bacterium,” Cheng said. “Transplanting these plants to infected areas may reduce mosquitoes’ ability to carry and transmit viruses.”
Xu Jianguo from the Chinese Center for Disease Control and Prevention, who was not involved in the study, commented on the potential of this approach. “Rosenbergiella_YN46 is derived from the natural environment, posing minimal environmental risk. It does not induce drug resistance in mosquitoes or affect their survival,” he noted.
The research team is also exploring other regions, such as the Leizhou Peninsula in south China’s Guangdong Province, to discover more bacteria that could inhibit the spread of mosquito-borne viruses. “The spread of Zika and epidemic encephalitis B might be contained if more beneficial bacteria can be found,” Cheng added.
This study demonstrates that utilizing bacteria-colonized field mosquitoes offers a feasible biocontrol strategy for reducing virus transmission and prevalence in nature, providing a promising avenue for combating mosquito-borne diseases.
Reference(s):
Scientists use gut bacteria to prevent mosquito-borne diseases
cgtn.com
