# The Symbiotic Bacterial Profile of Laboratory-Reared and Field-Caught Aedes albopictus Mosquitoes from Greece

## TL;DR

This study compares the bacterial communities in lab and wild Aedes albopictus mosquitoes from Greece, finding significant differences and identifying potential symbiotic bacteria for mosquito control.

## Contribution

The study identifies key symbiotic bacteria in Ae. albopictus populations in Greece, highlighting their potential for improving mosquito control techniques like SIT.

## Key findings

- Wild and lab-reared mosquitoes showed distinct bacterial profiles, with lab samples having higher diversity.
- Wolbachia was the dominant bacterium in most groups, with strains wAlbA and wAlbB prevalent in field-caught mosquitoes.
- Blood feeding increased Serratia abundance, and various Enterobacter, Klebsiella, and other bacteria were isolated for potential use as diet supplements.

## Abstract

The Asian tiger mosquito Aedes albopictus is a highly invasive species capable of transmitting human pathogens. For population management, the sterile insect technique (SIT) is considered an effective and sustainable alternative to conventional methods, such as insecticides and reducing or eliminating breeding sites. The use of symbiotic bacteria to improve the application of SIT or design combined SIT/incompatible insect technique (IIT) approaches is currently considered. In this context, exploring the microbiota of local mosquito populations is crucial for identifying interesting components. This study employed 16S rRNA sequencing and microbiological methods to characterize the diversity of laboratory and wild Ae. albopictus in Greece. Differences were recorded between wild and lab-reared mosquitoes, with laboratory samples exhibiting higher diversity. Laboratory treatment, sex, and developmental stage also resulted in variations between communities. Populations reared in the same facility developed mostly similar bacterial profiles. Two geographically distant wild populations displayed similar bacterial profiles, characterized by seasonal changes in the relative abundance of Pantoea and Zymobacter. Wolbachia was dominant in most groups (63.7% relative abundance), especially in field-caught mosquitoes. It was identified with two strains, wAlbA (21.5%) and wAlbB (42.2%). Other frequent taxa included Elizabethkingia, Asaia, and Serratia. Blood feeding favored an increase in Serratia abundance. Various Enterobacter, Klebsiella, Aeromonas, and Acinetobacter strains were isolated from larval and adult mosquito extracts and could be further characterized as diet supplements. These findings suggest that the microbiota of local populations is highly variable due to multiple factors. However, they retain core elements shared across populations that may exhibit valuable nutritional or functional roles and could be exploited to improve SIT processes.