Bacterium Found to Kill Malaria in Mosquitoes

This is another promising routeto attack malaria that should have been chased a lot sooner and probablywas.  It is an effective biologicalattack, that unfortunately is likely susceptible to improved counter strategiesin the end.  That is the Achilles heel ofall such protocols.  Of course we can getlucky and perhaps drive the problem to swift extinction in particular regionswhich does solve the problem until it once again inadvertently reintroduced.

Today we have watched the abruptreintroduction of the nearly extinct bed bug and re discovered just howdifficult it is to control without DDT.

We really need to revisit thewhole DDT protocol.  A blanket campaignaimed at driving a pest to extinction is certainly questionable but alsoeffective.  Ending the campaign thenallows a full recovery of other insects. 

I do think that applying DDT inthe urban environment may well be an acceptable strategy.  It allows the establishment of a protectiveperimeter for ordinary maintenance. 

Outside the city or town, the practiceis not justified in any manner and the same likely applies to a number of thepesticides and herbicides presently in use.

Pestcontrol requires a number of methods and this one appears to be an effectiveway to hugely lower the impact of malaria.

Bacterium Found to Kill Malaria in Mosquitoes

Released: 5/11/2011 1:05 PM EDT 

Source: JohnsHopkins Bloomberg School of Public Health

http://www.newswise.com/articles/view/576694/?sc=dwhn

Newswise — Researchers at the Johns Hopkins Bloomberg Schoolof Public Health have identified a bacterium in field-caught mosquitoes that,when present, stops the development of Plasmodium falciparum, the parasite thatcauses malaria in humans. According to the study, the Enterobacter bacterium ispart of the naturally occurring microbial flora of the mosquito’s gut and killsthe parasite by producing reactive oxygen species (or free radical molecules).The study is published in the May 13 edition of Science.

“We’ve previously shown that the mosquito’s midgut bacteria canactivate its immune system and thereby indirectly limit the development of themalaria parasite. In this study we show that certain bacteria can directlyblock the malaria parasite’s development through the production of freeradicals that are detrimental to Plasmodium in the mosquito gut,” said GeorgeDimopoulos, PhD, senior author of the study and associate professor at theW.Harry Feinstone Department of Molecular Microbiology and Immunology, and theJohns Hopkins Malaria Research Institute. “We are particularly excited aboutthis discovery because it may explain why mosquitoes of the same species andstrain sometimes differ in their resistance to the parasite, and we may alsouse this knowledge to develop novel methods to stop the spread of malaria. Onebiocontrol strategy may, for example, rely on the exposure of mosquitoes in thefield to this natural bacterium, resulting in resistance to the malariaparasite. ”

Like humans, mosquitoes have a variety of bacteria in their digestivesystems. For the study, the researchers isolated the Enterobacter bacteriumfrom the midgut of Anopheles mosquitoes collected near the Johns HopkinsMalaria Research Institute at Macha, which is located in southern Zambia. About25 percent of the mosquitoes collected contained the specific bacteria strain.Laboratory studies showed the bacterium inhibited the growth of Plasmodium upto 99 percent, both in the mosquito gut and in a test tube culture of the humanmalaria parasite. Higher doses of bacteria had a greater impact on Plasmodiumgrowth.

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

Authors of “Natural microbe-mediated refractorieness to Plasmodiuminfection in Anopheles gambiae” include Chris M. Cirmotich, Yuemei Dong, AprilM. Clayton, Simone L. Sandiford, and Jayme A. Souza-Neto of the Johns HopkinsBloomberg School of Public Health and Musapa Mulenga of the Malaria Instituteat Macha in Zambia.

The research was supported by the National Institutes ofHealth/National Institute of Allergy and Infectious Disease, and the JohnsHopkins Malaria Research Institute.