First report of natural infection of Anopheles gambiae s.s. and Anopheles coluzzii by Wolbachia and Microsporidia in Benin: a cross-sectional study

• Published in: Malaria Journal
• Main Authors: Minassou Juvénal Ahouandjinou, Arthur Sovi, Aboubakar Sidick, Wilfried Sewadé, Come Zinsou Koukpo, Saïd Chitou, Linda Towakinou, Bruno Adjottin, Steve Hougbe, Filémon Tokponnon, Germain Gil Padonou, Martin Akogbéto, Louisa A. Messenger, Razaki A. Ossè
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2024
• Subjects: Wolbachia; Microsporidia; Anopheles coluzzii; Anopheles gambiae; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1186/s12936-024-04906-1; https://doaj.org/article/4ffa041370b34084b60184569644ed0a

Abstract Background Recently, bacterial endosymbiont, including Wolbachia and Microsporidia were found to limit the infection of Anopheles mosquitoes with Plasmodium falciparum. This study aimed to investigate the natural presence of key transmission-blocking endosymbionts in Anopheles gambiae and Anopheles coluzzii in Southern Benin. Methods The present study was conducted in seven communes (Cotonou, Porto-Novo, Aguégués, Ifangni, Pobè Athiémé, and Grand-Popo) of Southern Benin. Anopheles were collected using indoor/outdoor Human Landing Catches (HLCs) and Pyrethrum Spray Catches (PSCs). Following morphological identification, PCR was used to identify An. gambiae sensu lato (s.l.) to species level and to screen for the presence of both Wolbachia and Microsporidia. Plasmodium falciparum sporozoite infection was also assessed using ELISA. Results Overall, species composition in An. gambiae s.l. was 53.7% An. coluzzii, while the remainder was An. gambiae sensu stricto (s.s.). Combined data of the two sampling techniques revealed a mean infection prevalence with Wolbachia of 5.1% (95% CI 0.90–18.6) and 1.3% (95% CI 0.07–7.8) in An. gambiae s.s. and An. coluzzii, respectively. The mean infection prevalence with Microsporidia was 41.0% (95% CI 25.9–57.8) for An. gambiae s.s. and 57.0% (95% CI 45.4–67.9) for An. coluzzii. Wolbachia was only observed in Ifangni, Pobè, and Cotonou, while Microsporidia was detected in all study communes. Aggregated data for HLCs and PSCs showed a sporozoite rate (SR) of 0.80% (95% CI 0.09–2.87) and 0.69% (95% CI 0.09–2.87) for An. gambiae and An. coluzzii, respectively, with a mean of 0.74% (95% CI 0.20–1.90). Of the four individual mosquitoes which harboured P. falciparum, none were also infected with Wolbachia and one contained Microsporidia. Conclusions The present study is the first report of natural infections of field-collected An. gambiae s.l. populations from Benin with Wolbachia and Microsporidia. Sustained efforts should be made to widen the spectrum of bacteria identified in ...