Wolbachia bacteria reduce parasite levels and kill the mosquito that spreads malaria

Wolbachia are bacteria that infect many insects, including mosquitoes. However, Wolbachia do not naturally infect Anopheles mosquitoes, which are the type that spreads malaria to humans. Researchers at the Johns Hopkins Bloomberg School of Public Health found that artificial infection with different Wolbachia strains can significantly reduce levels of the human malaria parasite, Plasmodium falciparum, in the mosquito, Anopheles gambiae. The investigators also determined that one of the Wolbachia strains rapidly killed the mosquito after it fed on blood. According to the researchers, Wolbachia could potentially be used as part of a strategy to control malaria if stable infections can be established in Anopheles. Their study is published in the May 19 edition PLoS Pathogens.

"This is the first time anyone has shown that Wolbachia infections can reduce levels of the human malaria parasite (Plasmodium falciparum) in Anopheles mosquitoes," said Jason Rasgon, PhD, senior author of the study and associate professor with the Johns Hopkins Malaria Research Institute and the Bloomberg School's W. Harry Feinstone Department of and Immunology.

For the study, Rasgon and his colleagues infected mosquitoes with two different Wolbachia strains (wMelPop and wAlbB). After infection, Wolbachia disseminated widely in the mosquitoes and infected diverse tissues and organs. Wolbachia also seemed to actively manipulate the mosquito's immune system to facilitate its own replication. Both Wolbachia strains were able to significantly inhibit malaria parasite levels in the mosquito gut. Although not virulent in sugar-fed mosquitoes, the wMelPop strain killed most mosquitoes within a day after the mosquito was blood-fed.

"These experiments show that Wolbachia could be used in multiple ways to control malaria, perhaps by blocking transmission or by killing infected mosquitoes," said Rasgon.

Worldwide, malaria afflicts more than 225 million people. Each year, the disease kills nearly 800,000, many of whom are children living in Africa.

More information: "Wolbachia infections are virulent and inhabit the human malaria parasite Plasmodium falciparum in Anopheles gambiae", PLoS Pathogens.

Related Stories

Malaria researchers identify new mosquito virus

Aug 22, 2008

Researchers at the Johns Hopkins Bloomberg School of Public Health's Malaria Research Institute have identified a previously unknown virus that is infectious to Anopheles gambiae—the mosquito primarily respon ...

Scientists find bacterium can halt dengue virus transmission

Apr 01, 2010

Dengue fever -- caused by a virus transmitted by mosquitoes -- threatens 2.5 billion people each year and there is no vaccine or treatment. New research by Michigan State University entomologists has found that a bacterium ...

Malaria immunity trigger found for multiple mosquito species

Mar 13, 2009

(PhysOrg.com) -- Researchers at the Johns Hopkins Bloomberg School of Public Health have for the first time identified a molecular pathway that triggers an immune response in multiple mosquito species capable of stopping ...

Recommended for you

Fatigue, fear are daily lot of Ebola fighters: experts

56 minutes ago

Doctors, nurses and hospital workers fighting the Ebola epidemic in west Africa are struggling with a daily burden of exhaustion, shortage of staff and fear for themselves over the deadly virus, specialists say.

Hong Kong makes Ebola 'contingency' measures

4 hours ago

Hong Kong said Wednesday it was quarantining all people from Guinea, Sierra Leone and Liberia who were showing Ebola-like symptoms on arrival in the city, as fears grow worldwide about the spread of the deadly virus.

EU ready for Ebola threat: sources

7 hours ago

The European Union is equipped and ready to treat victims should the deadly Ebola virus, which has killed hundreds in West Africa, be found in member states, EU sources said Wednesday.

Reducing kidney injury using a quality improvement method

11 hours ago

Using quality improvement measures in eight of the 10 hospitals in the Northern New England Cardiovascular Disease Study Group, researchers have found a way to reduce kidney injury in patients undergoing a procedure with ...

App for headache sufferers shows success

23 hours ago

A unique app that helps headache sufferers to record the severity and regularity of their pain is being used as part of a Griffith research study.

User comments