
AsianScientist (Jun. 22, 2017) – In a study published in the Proceedings of the National Academy of Science, researchers have found that a mosquito’s gut bacteria play a role in its susceptibility to fungal infections.
The mosquito gut harbors a vast array of commensal bacteria which perform many functions for host physiology and health, particularly in modulating host immune homeostasis and the outcome of pathogenic infections.
Unlike viruses, bacteria and parasites, which need to be ingested to cause disease, fungal pathogens infect mosquitoes through the cuticle and proliferate in the hemolymph. However, fungal pathogenesis studies have primarily focused on interactions between the fungus and the host insect, without considering its possible interactions with the gut microbiota.
In the present study, Professor Wang Sibao and his colleagues at Shanghai Institute of Plant Physiology and Ecology of Chinese Academy of Sciences discovered that gut microbiota can accelerate the death of mosquitoes infected by fungi.
They reported that mosquitoes with gut microbiota die significantly faster than mosquitoes without microbiota after being infected with the pathogenic fungus Beauveria bassiana. Fungal infection induces imbalance of gut bacteria by causing the overgrowth of the opportunistic pathogenic bacterium Serratia marcescens that spreads through the mosquito’s circulatory system and promotes fungal killing.
Furthermore, fungal infection resulted in the down-regulation of antimicrobial peptides and dual oxidase in the mosquito midgut, consequently disrupting the balance of different species in the microbiota.
These findings shed new light on the role of the gut microbiota in fungal infections of insects, and may yield new strategies for the biological control of mosquitoes and the diseases they spread.
The article can be found at: Wei et al. (2017) Insect Pathogenic Fungus Interacts with the Gut Microbiota to Accelerate Mosquito Mortality.
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Source: Chinese Academy of Sciences; Photo: CDC Global/Flickr/CC
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