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. Similar to higher organisms, 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 pathogen extrinsic incubation period all influence pathogen transmission. Interestingly, the 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 in the biology of the mosquito – microbe symbiosis that need to be addressed in order to understand these interactions more thoroughly and exploit them efficiently. Here, we review current evidence of the impacts of the microbiome on aspects of vectorial capacity highlighting opportunities for novel vector control strategies and areas where further studies are required.

Inter-species microbiota transplantation recapitulates microbial acquisition and persistence in mosquitoes

“…Numerous studies describing the diversity and function of mosquito-associated microbial taxa and assemblages have been published recently, leading to the discovery of potential interactions between mosquitoes and their microbiota that could be manipulated to enhance or reduce mosquito fitness and/or vector competency (reviewed in [36]). However, questions remain about the reproducibility, applicability, and physiological relevance of these data owing to discrepancies in experimental technique, lack of standardization, and the use of laboratory-colonized mosquito strains and species that harbor microbiota that vary substantially within and between different laboratories and that differ substantially from naturally occurring mosquitoes in the field [12,13,[69][70][71][72][73][74].…”

“…Altogether, the microbiota associated with the mosquito gut and other tissues can have profound impacts on mosquito biology by modulating larval growth and development [10,12,[27][28][29] as well as adult survival [30][31][32], reproduction [27,33], and the competency of adult female mosquitoes to transmit human pathogens [34]. As such, there is a growing interest in exploiting microbes for vector control [35][36][37]. However, available tools to manipulate the microbiota in mosquitoes are limited, lagging behind research in other systems [38][39][40][41].…”

Aedes mosquitoes in the emerging threat of urban yellow fever transmission

“…The interactions between mosquito microbiota and arbovirus depends on the composition of microbiota that a mosquito acquired from different environments. Thus, the microbiota diversity among geographic populations could be another factor that shapes the mosquito vector competence, and subsequently limiting the spreading of YFV 103,104 …”

Assessment of Plasmodium falciparum infection and fitness of genetically modified Anopheles gambiae aimed at mosquito population replacement

“…A similar pattern was evident for the abundance of Flavobacteriaceae, which was higher in both +/+ and +/-compared to -/-mosquitoes (Mann-Whitney, p<0.001, p<0.01 respectively). The increased bacterial load may also be associated with the reduced lifespan of the Aper1-Sco GM mosquitoes (Cansado-Utrilla et al, 2021).…”