Characterisation of bacterial symbionts of the Anopheles funestus group from KwaZulu-Natal Province, South Africa

Anopheles funestus s.s. is the anthropophilic member of a group of mosquitoes that was the only member considered a malaria vector until recently. However, Anopheles parensis and Anopheles vaneedeni have recently been suspected to be implicated in disease transmission and may contribute to the residual malaria problem in South Africa. Unlike An. funestus s.s, the rest of the group would be more difficult to control due to their outdoor biting and resting behaviours. Thus, alternative vector control methods efficient in controlling both outdoor and indoor biting populations would be beneficial in controlling such secondary vectors. One of these alternative efforts is paratransgenesis, a technique that aims to inhibit Plasmodium infection through transgenesis by bacterial symbionts. Yet, bacterial symbionts of the An. funestus group are poorly studied. This study characterised the microbiota of the digestive system (salivary glands and midguts) of the An. funestus group by sequencing the V3-V4 hypervariable region of bacterial 16S rRNA genes in F1 An. rivulorum, An. vaneedeni and An. parensis sampled from KwaZulu-Natal Province, South Africa. Although alpha diversity did not differ significantly, beta diversity, differential abundance and relative abundance varied between the different members of the An. funestus group. Overall, there were shared bacterial genera between the different members of the An. funestus group, which were Agromyces, Rahnella, Acinetobacter, Microbacterium and Asaia. The study revealed a core microbiota in the digestive system of the An. funestus group which could be further explored for the use of paratransgenesis for the control of members of the An. funestus group.