The microbiome and mosquito vectorial capacity: rich potential for discovery and translation

Abstract

Microbiome research has gained considerable interest due to the emerging evidence of its impact on human and animal health. As in other animals, the gut-associated microbiota of mosquitoes affect host fitness and other phenotypes. It is now well established that microbes can alter pathogen transmission in mosquitoes, either positively or negatively, and avenues are being explored to exploit microbes for vector control. However, less attention has been paid to how microbiota affect phenotypes that impact vectorial capacity. Several mosquito and pathogen components, such as vector density, biting rate, survival, vector competence, and the pathogen extrinsic incubation period all influence pathogen transmission. Recent studies also indicate that mosquito gut-associated microbes can impact each of these components, and therefore ultimately modulate vectorial capacity. Promisingly, this expands the options available to exploit microbes for vector control by also targeting parameters that affect vectorial capacity. However, there are still many knowledge gaps regarding mosquito-microbe interactions that need to be addressed in order to exploit them efficiently. Here, we review current evidence of impacts of the microbiome on aspects of vectorial capacity, and we highlight likely opportunities for novel vector control strategies and areas where further studies are required. Video abstract.

Keywords: Biting; Competence; Density; Extrinsic incubation period; Longevity; Microbiome; Mosquito; Pathogen transmission; Symbiosis; Vectorial capacity.

Fig. 1

Vectorial capacity (VC) equation and the effects of the microbiome on mosquito vectorial capacity. The mosquito microbiome can modulate the five components of vectorial capacity. These components are vector density (m), vector biting rate (a), vector competence (b), pathogen extrinsic incubation period (N) and probability of vector daily survival (p). The microbiome can impact the probability of vector daily survival by modulating mosquito fitness, interacting with other microbes and affecting insecticide resistance. It can also affect vector density through effects on host growth, development and reproductive output and by modulating their resistance to abiotic stress