Assessing the microbiome in Anopheles coluzzii and Anopheles gambiae from natural swarm

Simon P. Sawadogo, Didier A. Kabore, Olivier Gnankine, Abdoulaye Diabate, Hilary Ranson, Grant Hughesand Roch K. Dabire

Background: Microbiome play key roles in the physiology and vector competence of mosquitoes borne diseases and can influence their behaviour, reproduction, and susceptibility to pathogens. This study characterizes the microbiome of males Anopheles gambiae and An. coluzzii successfully mated versus unmated collected from natural swarm.

Methods: Mated and unmated mosquitoes were collected in Vallée du Kou and Soumousso, two distinct environments representative of different ecological communities of An. gambiae s.l., DNA was extracted from 100 An. gambiae complex mosquitoes: 50 males from Bama (25 mated and 25 unmated) and 50 males from Soumousso (25 mated and 25 unmated). Bacterial communities were identified using high throughput sequencing targeting 16S rRNA gene.

Results: A total of 41 bacterial phyla was found among all samples. Proteobacteria (74.4%) was most dominant, followed by Firmicutes (12.0%), Bacteroidetes (4.64%), and Actinobacteria (3.6%). The Wilcoxon Rank Sum test highlighted differential abundances in the Operational Taxonomic Units (OTUs) assigned at the Phyla level across our samples (P < 0.05). The unmated males harbored OTUs with higher abundances in Bama samples whereas at Soumousso mated males exhibit higher abundance. However, there is no significant difference was found in term of bacterial communities’ diversity between mated and unmated males. Interestingly, some endosymbionts known to get potential relevance for malaria control as Thorsellia (20%), Asaia (32%), Spiroplasma (6%) Rickettsia (18%), and Wolbachia (1%) were detected.

Conclusions: Our study provides a first details analysis of the microbiome composition of mated and unmated males of main human disease including endosymbiotic bacteria that can be potentially exploited in terms of vector control strategy.

Keywords: Mosquito microbiome, 16S rRNA gene amplicon sequencing, Mated, Unmated, Anopheles gambiae, Anopheles coluzzii, Mating success.