Cultured skin microbiota attracts malaria mosquitoes

Abstract Background Host-seeking of the African malaria mosquito, Anopheles gambiae sensu stricto , is guided by human odours. The precise nature of the odours, and the composition of attractive blends of volatiles, remains largely unknown. Skin microbiota plays an important role in the production o...

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Bibliographic Details
Published in:Malaria Journal
Main Authors: Takken Willem, Knols Bart GJ, Beijleveld Hans, Verhulst Niels O, Schraa Gosse, Bouwmeester Harro J, Smallegange Renate C
Format: Article in Journal/Newspaper
Language:English
Published: BMC 2009
Subjects:
Online Access:https://doi.org/10.1186/1475-2875-8-302
https://doaj.org/article/26464b58836d415c85570b7f044e594b
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Summary:Abstract Background Host-seeking of the African malaria mosquito, Anopheles gambiae sensu stricto , is guided by human odours. The precise nature of the odours, and the composition of attractive blends of volatiles, remains largely unknown. Skin microbiota plays an important role in the production of human body odours. It is hypothesized that host attractiveness and selection of An. gambiae is affected by the species composition, density, and metabolic activity of the skin microbiota. A study is presented in which the production and constituency of volatile organic compounds (VOCs) by human skin microbiota is examined and the behavioural responses of An. gambiae to VOCs from skin microbiota are investigated. Methods Blood agar plates incubated with skin microbiota from human feet or with a reference strain of Staphylococcus epidermidis were tested for their attractiveness to An. gambiae in olfactometer bioassays and indoor trapping experiments. Entrained air collected from blood agar plates incubated with natural skin microbiota or with S. epidermidis were analysed using GC-MS. A synthetic blend of the compounds identified was tested for its attractiveness to An. gambiae . Behavioural data were analysed by a χ 2 -test and GLM. GC-MS results were analysed by fitting an exponential regression line to test the effect of the concentration of bacteria. Results More An. gambiae were caught with blood agar plates incubated with skin bacteria than with sterile blood agar plates, with a significant effect of incubation time and dilution of the skin microbiota. When bacteria from the feet of four other volunteers were tested, similar effects were found. Fourteen putative attractants were found in the headspace of the skin bacteria. A synthetic blend of 10 of these was attractive to An. gambiae . Conclusions The discovery that volatiles produced by human skin microorganisms in vitro mediate An. gambiae host-seeking behaviour creates new opportunities for the development of odour-baited trapping systems. Additionally, ...