01 June 2013 Bugs Help Out Bacteria might seem unlikely allies when fighting disease, yet they could hold the key to controlling malaria. This deadly tropical illness is caused by Plasmodium parasites, transmitted to humans via mosquito bites. However, mosquitoes can be made somewhat resistant to the parasite, by infecting them with Wolbachia bacteria, which block the parasite’s development. Infected individuals thus carry, and transmit, far fewer parasites. Researchers have recently succeeded in infecting Anopheles stephensi, a species largely responsible for malarial transmission in the Middle East and Asia; the picture reveals the presence of Wolbachia (stained green) in a mosquito’s ovaries. Infected females pass Wolbachia on to their offspring, and infected males only breed successfully with infected females, so parasite resistance quickly spreads within the population. A similar technique, applied to mosquitoes transmitting the virus responsible for dengue fever, has yielded promising results, raising hopes that this approach might provide solutions for malaria too. Written by Emmanuelle Briolat — Zhiyong Xi Michigan State University, USA Reprinted with permission from AAAS. Published in Science 340(6133): 748-751
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01 June 2013

Bugs Help Out

Bacteria might seem unlikely allies when fighting disease, yet they could hold the key to controlling malaria. This deadly tropical illness is caused by Plasmodium parasites, transmitted to humans via mosquito bites. However, mosquitoes can be made somewhat resistant to the parasite, by infecting them with Wolbachia bacteria, which block the parasite’s development. Infected individuals thus carry, and transmit, far fewer parasites. Researchers have recently succeeded in infecting Anopheles stephensi, a species largely responsible for malarial transmission in the Middle East and Asia; the picture reveals the presence of Wolbachia (stained green) in a mosquito’s ovaries. Infected females pass Wolbachia on to their offspring, and infected males only breed successfully with infected females, so parasite resistance quickly spreads within the population. A similar technique, applied to mosquitoes transmitting the virus responsible for dengue fever, has yielded promising results, raising hopes that this approach might provide solutions for malaria too.

Written by Emmanuelle Briolat

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Source: bpod.mrc.ac.uk

Neglected Bacteria When it comes to their human impact, mosquitoes punch way above their weight. These tiny parasites spread many human diseases, including dengue fever, which infects up to 100 million people every year. Mosquito-borne diseases are notoriously hard to control, however, a new approach using Wolbachia, a common bacterium that infects the majority of insects, offers hope. Wolbachia is a selfish guest, and doesn’t like sharing. Like squatters laying their claim, the bacteria lock the door to any new tenants looking for a place to stay inside cells. And so mosquitoes already carrying Wolbachia very rarely become infected with devastating dengue virus. Areas, such as these eye cells, riddled with dengue (stained red) are virus-free when Wolbachia (stained bright green on the right) is present. Combined with the fact that Wolbachia cuts a mosquito’s lifespan in half, this enemy of the insect world could turn out to be our best friend. Written by Jan Piotrowski — Scott O’Neill The University of Queensland, Australia Copyright Elsevier 2009 Published in Cell 139(7): 1268-1278
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Neglected Bacteria

When it comes to their human impact, mosquitoes punch way above their weight. These tiny parasites spread many human diseases, including dengue fever, which infects up to 100 million people every year. Mosquito-borne diseases are notoriously hard to control, however, a new approach using Wolbachia, a common bacterium that infects the majority of insects, offers hope. Wolbachia is a selfish guest, and doesn’t like sharing. Like squatters laying their claim, the bacteria lock the door to any new tenants looking for a place to stay inside cells. And so mosquitoes already carrying Wolbachia very rarely become infected with devastating dengue virus. Areas, such as these eye cells, riddled with dengue (stained red) are virus-free when Wolbachia (stained bright green on the right) is present. Combined with the fact that Wolbachia cuts a mosquito’s lifespan in half, this enemy of the insect world could turn out to be our best friend.

Written by Jan Piotrowski

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Published in Cell 139(7): 1268-1278
Parasitic Assistance Dengue fever affects 50 to 100 million people a year worldwide. Tens of thousands of people will die despite treatment. So there is much interest in strategies that prevent the spread of the disease. The virus hitches a ride with the Aedes aegypti mosquito and much effort has gone into widespread treatment with insecticides. Resistant mosquitos have, however, put paid to such approaches. New research into biological control methods has uncovered a promising candidate in the form of the fungus, Beauveria bassiana (pictured). The fungus is already being used to control other agricultural pests. And recently, scientists ascertained that it effectively kills dengue-carrying mosquitos. Mosquitos blighted by the fungus laid fewer eggs and were 30% less likely to bite humans. The million-dollar question is now how to introduce the fungus into areas where dengue continues to kill. Written by Brona McVittie — Courtesy of George Barron
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Parasitic Assistance

Dengue fever affects 50 to 100 million people a year worldwide. Tens of thousands of people will die despite treatment. So there is much interest in strategies that prevent the spread of the disease. The virus hitches a ride with the Aedes aegypti mosquito and much effort has gone into widespread treatment with insecticides. Resistant mosquitos have, however, put paid to such approaches. New research into biological control methods has uncovered a promising candidate in the form of the fungus, Beauveria bassiana (pictured). The fungus is already being used to control other agricultural pests. And recently, scientists ascertained that it effectively kills dengue-carrying mosquitos. Mosquitos blighted by the fungus laid fewer eggs and were 30% less likely to bite humans. The million-dollar question is now how to introduce the fungus into areas where dengue continues to kill.

Written by Brona McVittie

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Courtesy of George Barron

Source: bpod.mrc.ac.uk