Blood meal source and mixed blood-feeding influence gut bacterial community composition in Aedes aegypti

Ephantus J Muturi,Carla E Cáceres,Christopher Dunlap,Teresia M Njoroge

doi:10.1186/s13071-021-04579-8

Abstract

BackgroundThe guts of blood-sucking insects host a community of bacteria that can shift dramatically in response to biotic and abiotic factors. Identifying the key factors structuring these microbial communities has important ecological and epidemiological implications.MethodsWe used the yellow fever mosquito, Aedes aegypti, to investigate the impact of mixed blood meals on gut microbiota of vector mosquitoes. Adult females were experimentally fed on sugar or blood from chicken, rabbit or a mixture of chicken and rabbit blood, and their gut microbiota were characterized using 16S rRNA gene amplification and MiSeq sequencing.ResultsThe gut bacterial communities of mosquitoes fed on the three blood meal treatments clustered separately, suggesting that host species identity and mixed blood-feeding are key determinants of gut bacterial community composition in mosquitoes. Mixed blood meal had a synergistic effect on both operational taxonomic unit (OTU) richness and the Shannon diversity index, suggesting that mixed blood-feeding can offset the nutritional deficit of blood meals from certain host species. The microbial communities observed in this study were distinct from those identified from similarly fed Ae. aegypti from our previous study.ConclusionsThese findings demonstrate that vector host-feeding preferences can influence gut microbial composition and diversity, which could potentially impact pathogen acquisition and transmission by the vector. The results also demonstrate that different microenvironmental conditions within the laboratory may play an important role in structuring the microbial communities of independently reared mosquito colonies.Graphical

Highlights

The guts of blood-sucking insects host a community of bacteria that can shift dramatically in response to biotic and abiotic factors
The total number of operational taxonomic unit (OTU) identified by sample type were 66 OTUs in newly emerged adults, 58 OTUs in sugar-fed mosquitoes, 21 OTUs in mosquitoes fed on chicken blood, 39 OTUs in mosquitoes fed on rabbit blood and
This simplified model system may not be a perfect representation of the complex system that occurs in nature, it highlights the need for further studies to decipher the ecological and epidemiological impact of mixed blood feeding by different mosquito species and other hematophagous arthropods

Summary

Introduction

The guts of blood-sucking insects host a community of bacteria that can shift dramatically in response to biotic and abiotic factors. The majority of arthropod-borne pathogens and parasites infect multiple host species, and due to heterogeneities. Muturi et al Parasites Vectors (2021) 14:83 key determinants of epidemiological dynamics for vector-borne pathogens and are typically used to understand the natural transmission dynamics, predict disease risk and inform disease surveillance and control efforts. Factors that disrupt the composition of these microbial communities may indirectly alter pathogen transmission dynamics by modifying the components of vectorial capacity, including vector competence, daily survivorship, vector density and biting rates. Vector-feeding on multiple host species within the same gonotrophic cycle is fairly common in nature [24,25,26,27,28,29,30,31], the impact of mixed blood meals on vector gut microbial communities remains poorly understood

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