Infection of highly insecticide-resistant malaria vector Anopheles coluzzii with an environmentally friendly entomopathogenic bacteria Chromobacterium violaceum reduces its survival, blood feeding propensity and fecundity

Abstract

This is now a concern that malaria eradication will not be achieved without the introduction of novel control tools. Microbiological control might be able to make a greater contribution to vector control in the future. Here, we studied the impact of Chromobacterium violaceum infections isolated from wild caught Anopheles gambiae s.l. mosquitoes in Burkina Faso on mosquito survival, blood feeding and fecundity propensy. C. violaceum kills pyrethroid resistant mosquitoes An. coluzzii (LT80 ~ at 108 bacteria cell/ml of sugar meal). Interestingly, this bacterium had other negative effects on mosquito lifespan by significantly reducing (~59%, P<0.001) the mosquito feeding willingness from day 4-post infection to 9-day post infection. Moreover, C.violaceum considerably jeopardized the mosquito egg laying and hatching of mosquitoes by ~77.93% and ~22 % respectively. Mosquitoes infected with C. violaceum also showed significantly higher retention rates of immature eggs and follicles. These data showed important entomopathogenic properties of Burkina Faso C. violaceum strains. However, additional studies as the sequencing of C. violaceum genome and the potential toxins secreted will certainly provide useful information render it a potential candidate for the biological control strategies of malaria.