# Molecular characterization of potential Plasmodium-Blocking Serratia spp. bacteria in field-caught malaria mosquito in Burkina Faso

## TL;DR

This study identifies Serratia bacteria in wild malaria mosquitoes in Burkina Faso, suggesting their potential to block Plasmodium transmission.

## Contribution

The study reports the molecular characterization of Serratia spp. in Anopheles mosquitoes from Burkina Faso, revealing distinct strains with potential anti-malarial properties.

## Key findings

- Serratia strains isolated from Burkina Faso mosquitoes are phylogenetically distinct from those in neighboring countries.
- Serratia prevalence in malaria vectors was 13.3%, varying by mosquito stage, organ, and location.
- Only one mosquito was co-infected with Serratia and Plasmodium falciparum, indicating potential anti-Plasmodium effects.

## Abstract

One of the alternatives for controlling malaria is using mosquito symbiotic bacteria to reduce Plasmodium transmission. Species of Serratia, a genus of the Enterobacteriaceae family, have been isolated from the midgut of mosquitoes and are commonly found in water, soil and plant surfaces. These bacteria have shown great promise in blocking the transmission of Plasmodium in mosquitoes. The aim of this study was to isolate and characterize the genus Serratia within the Anopheles gambiae complex from Burkina Faso.

Mosquitoes were collected in three field sites located in Houet Province in western Burkina Faso (Dioulassoba, Vallée du Kou and Soumousso), transported to the laboratory and identified morphologically. The salivary gland, midgut, spermatheca, ovary of females and testis of males were dissected and their contents ground up. Different species of Serratia were identified by PCR targeting of the luxS gene of Serratia, followed by 16S ribosomal RNA (rRNA) sequencing.

Molecular analyses identified the isolates as belonging to the genus Serratia, and phylogenetic reconstruction revealed that these strains are highly similar to one another but distinct from Serratia strains previously reported in neighboring countries such as Ghana and Nigeria. The overall prevalence of Serratia among malaria vectors was 13.3%. This prevalence varied according to the development stage of mosquitoes, locality of origin and mosquito organ. Only one Anopheles coluzzii mosquito was co-infected with Serratia and Plasmodium falciparum.

The results of this study support the presence of Serratia spp. in wild mosquitoes from Burkina Faso, we well as their potential use in malaria control.

The online version contains supplementary material available at 10.1186/s13071-025-07191-2.