Parasite bacteria may help fight spread of mosquito-borne diseases

Oct 01, 2009
This picture shows an adult female Ae. aegypti mosquito biting. Researchers have shown that infecting the Aedes aegypti mosquito with the wMelPop strain of Wolbachia parasite inhibits transmission of the filarial nematode. Credit: Wellcome Images

Infecting mosquitoes with a bacterial parasite could help prevent the spread of lymphatic filariasis, one of the major neglected tropical diseases of the developing world, according to research published today in the journal Science.

Lymphatic filariasis affects more than 120 million people worldwide - over 40 million of these are seriously incapacitated and disfigured by the disease. It is caused by infection with the parasitic filarial nematode, a threadlike worm that is spread by and occupies the . In chronic cases, infection leads to a condition known as elephantiasis, which can cause severe swelling in the legs, male scrotum and female breasts.

Previous research has shown that infecting a mosquito with a strain of the bacterial parasite Wolbachia known as wMelPop - nicknamed 'popcorn' - can halve its lifespan. Mosquito-borne parasites such as the filarial nematode or the require an between ingestion and transmission, so only older mosquitoes can be infective. Skewing the mosquito population towards younger individuals reduces the number of infectious insects.

Now, researchers funded primarily by the Wellcome Trust have shown that as well as reducing the mosquito's lifespan, wMelPop directly inhibits transmission of the filarial nematode by encouraging the mosquito's to attack the worm. They found that significantly reduced numbers of filarial nematodes developed in mosquitoes infected with wMelPop - in some cases, less than 15% of the number in mosquitoes which were not carrying wMelPop.

"Wolbachia infection appears to significantly increase the activity of around two hundred mosquito genes, many of which are involved in the immune response," says Dr Steven Sinkins, a Wellcome Trust Senior Research Fellow at the University of Oxford. "This then primes the mosquito's immune system to fight infection by the filarial nematodes, preventing the worm from developing to a stage where transmission to humans is possible."

Wolbachia infections - including wMelPop - have also been shown to protect against certain viruses. Today's research suggests that this effect could also be a result of the boost to the mosquito's immune system.

Dr Sinkins and colleagues are currently looking at whether infecting other species of mosquito, such as Anopheles gambiae - the mosquito responsible for the majority of malaria infections - with wMelPop will have a similar effect and help inhibit malaria transmission as well as filariasis transmission. Another potential target is the Aedes polynesiensis mosquito, which spreads lymphatic filariasis in the islands of Polynesia, where decades of mass drug administration have failed to eradicate the filarial parasites from the human population.

"The Wolbachia 'popcorn' strain is a naturally-occurring organism found in a particular species of fruit fly which, if successfully introduced into mosquito populations, could potentially help us fight a number of the world's most serious diseases," says Dr Sinkins.

Wolbachia have been shown in previous studies to be capable of spreading rapidly through insect populations. When a male carrying Wolbachia mates with a female that does not, the resulting eggs fail to develop. However, a female that is infected with Wolbachia can breed successfully with any male, and thus produces more offspring on average than Wolbachia-uninfected females.

Source: Wellcome Trust (news : web)

Explore further: Cell division speed influences gene architecture

add to favorites email to friend print save as pdf

Related Stories

Mosquito parasite may help fight dengue fever

May 01, 2009

Dengue fever is a terrible viral disease blighting many of the world's tropical regions. Carried by mosquitoes, such as Aedes aegypti, 40% of the world's population is believed to be at risk from the infect ...

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

Cell division speed influences gene architecture

Apr 23, 2014

Speed-reading is a technique used to read quickly. It involves visual searching for clues to meaning and skipping non-essential words and/ or sentences. Similarly to humans, biological systems are sometimes ...

Secret life of cells revealed with new technique

Apr 23, 2014

(Phys.org) —A new technique that allows researchers to conduct experiments more rapidly and accurately is giving insights into the workings of proteins important in heart and muscle diseases.

In the 'slime jungle' height matters

Apr 23, 2014

(Phys.org) —In communities of microbes, akin to 'slime jungles', cells evolve not just to grow faster than their rivals but also to push themselves to the surface of colonies where they gain the best access ...

Queuing theory helps physicist understand protein recycling

Apr 22, 2014

We've all waited in line and most of us have gotten stuck in a check-out line longer than we would like. For Will Mather, assistant professor of physics and an instructor with the College of Science's Integrated Science Curriculum, ...

User comments : 0

More news stories

New breast cancer imaging method promising

The new PAMmography method for imaging breast cancer developed by the University of Twente's MIRA research institute and the Medisch Spectrum Twente hospital appears to be a promising new method that could ...

Research proves nanobubbles are superstable

The intense research interest in surface nanobubbles arises from their potential applications in microfluidics and the scientific challenge for controlling their fundamental physical properties. One of the ...

Using antineutrinos to monitor nuclear reactors

When monitoring nuclear reactors, the International Atomic Energy Agency has to rely on input given by the operators. In the future, antineutrino detectors may provide an additional option for monitoring. ...