Abstract
BackgroundVector control is critical in reducing the disease burden caused by mosquitoes, and insecticides are an effective tool to control vector populations. Resistance to common insecticides is now widespread, and novel classes of insecticides are needed. In previous work, we described the mosquitocidal activity of Chromobacterium sp. Panama (C.sp_P), a bacterium found in association with mosquitoes in natural populations. In the current work, we further explored the effects of exposure to the bacterium on mosquito fitness and mosquito physiology.ResultsWe found that C.sp_P has mosquitocidal activity against a broad range of mosquito taxa. When exposed to C.sp_P as adults, female An. gambiae suffered reduced longevity, but experienced no change in fecundity. The offspring of these females, however, had higher mortality as larvae and were slower to develop compared to offspring of control females. We also found that the mosquitocidal activity of C.sp_P was retained after removal of live cells from biofilm culture media, suggesting the bacteria secrete mosquitocidal compound(s) into the media during growth. Exposure to this cell-free C.sp_P-conditioned media caused female midgut transcriptional changes comprising detoxification, xenobiotic response, and stress response genes, suggesting the physiological response to C.sp_P is similar to that of insecticide exposure. Finally, we found that multiple members of the Chromobacterium genus had mosquitocidal activity, but this activity was highest in mosquitoes treated with C.sp_P.ConclusionsOur findings suggest that C.sp_P produces factor(s) with strong effects on mosquito longevity and fitness, which may be of interest for mosquitocide development. More generally, they indicate that further exploration of mosquito-associated and environmental microbes for novel insecticidal compounds or biocontrol agents is warranted.
Highlights
Vector control is critical in reducing the disease burden caused by mosquitoes, and insecticides are an effective tool to control vector populations
We found C. sp_P to have strong mosquitocidal activity against Anopheles gambiae and Aedes aegypti adult females when exposed to the bacteria in a sugar meal [17]
Chromobacterium violaceum was obtained from American Type Culture Collection (ATCC), and other species of Chromobacterium were obtained from the Leibniz Institute Deutsche Sammlung von Mikroorganismen und Zellkulturen (DSMZ): C. aquaticum (DSM 19852), C. subtsugae (DSM 17043) and C. vaccinii (DSM 25150)
Summary
Vector control is critical in reducing the disease burden caused by mosquitoes, and insecticides are an effective tool to control vector populations. Sp_P to have strong mosquitocidal activity against Anopheles gambiae (a primary vector of the malaria parasite Plasmodium falciparum) and Aedes aegypti (the primary vector of dengue and Zika viruses) adult females when exposed to the bacteria in a sugar meal [17]. When present in the mosquito midgut, C.sp_P reduced susceptibility of An. gambiae and Ae. aegypti mosquitoes to Plasmodium falciparum and dengue virus, respectively [17]. These anti-pathogen properties are active in vitro (i.e. independent of the mosquito), suggesting the bacteria produces compound(s) with antipathogen activity [17]. A patent has been filed reporting that C. vaccinii is active against moths and Ae. aegypti mosquito larvae [21]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
