Diverse novel Wolbachia bacteria strains and genera-specific co-infections with Asaia bacteria in Culicine mosquitoes from ecologically diverse regions of Cameroon

Abstract

Background: The endosymbiotic bacterium Wolbachia infects numerous species of insects and Wolbachia transinfection of Aedes mosquito species is now being used for biocontrol programs as Wolbachia strains can both inhibit arboviruses and invade wild mosquito populations. The discovery of novel, resident Wolbachia strains in mosquito species warrants further investigation as potential candidate strains for biocontrol strategies. Methods: We obtained mosquito specimens from diverse Culicine mosquitoes from Cameroon including ecologically diverse locations in the Central and West Regions. Wolbachia prevalence rates were assessed in addition to the environmentally acquired bacterial species Asaia in major Culicine genera. PCR-based methods were also used with phylogenetic analysis to confirm identities of host mosquito species and Wolbachia strains were classified using multi-locus sequence typing (MLST). Results: We report high Wolbachia prevalence rates for Culicine species, including in a large cohort of Aedes africanus collected from west Cameroon in which 100% of mono-specific pools were infected. Furthermore, co-infections with Asaia bacteria were observed across multiple genera, demonstrating that these two bacteria can co-exist in wild mosquito populations. Wolbachia strain MLST and phylogenetic analysis provided evidence for diverse Wolbachia strains in 13 different mosquito species across seven different genera. Full or partial MLST profiles were generated from resident Wolbachia strains in six Culex species (quinquefasciatus, watti, cinerus, nigripalpus, perexiguus and rima), two Aedes species (africanus and denderensis) and in Mansonia uniformis, Catageiomyia argenteopunctata, Lutzia tigripes, Eretmapodites chrysogaster and Uranotaenia bilineata. Conclusions: Our study provides further evidence that Wolbachia is widespread within wild mosquito populations of diverse Culicine species and provides further candidate strains that could be investigated as future options for Wolbachia-based biocontrol to inhibit arbovirus transmission.

Genetic diversity of endosymbiotic bacteria Wolbachia infecting two mosquito species of the genus Eretmapodites occurring in sympatry in the Comoros archipelago

“…However, no Wolbachia strain type was assigned to the combination of these five alleles in the pubMLST database. Hence, we considered this Wolbachia strain type as new and named it “ w EretB.” The MLST allelic profiles of w EretA and w EretB appeared genetically different from those of a Wolbachia strain previously described in the species Eretmapodites chrysogaster from Cameroon for which coxA matched with #275, ftsZ matched with #106, and fbpA matched with #6 (Osuna et al, 2023 ). Using complete MLST profiles obtained for 84 mosquitoes (83 Er.…”

“…Wolbachia have been well studied in various medically importance mosquito species of such as Culex pipiens pipiens and Culex pipiens quinquefasciatus (Duron et al, 2005 ; Atyame et al, 2011 , 2014 ; Dumas et al, 2013 ), Aedes albopictus (Kambhampati et al, 1993 ; Armbruster et al, 2003 ; Tortosa et al, 2010 ; Zouache et al, 2011 ), as well as more recently in Anopheles species (Baldini et al, 2014 ; Ayala et al, 2019 ) and Aedes aegypti (Coon et al, 2016 ; Thongsripong et al, 2018 ). However, there have been limited studies on the presence of Wolbachia in mosquitoes of the Eretmapodites genus (Tokash-Peters et al, 2022 ; Osuna et al, 2023 ), despite their role in the arbovirus transmission (arthropod-borne viruses) (Bamou et al, 2021 ; Cêtre-Sossah et al, 2023 ).…”

Wolbachia and Asaia Distribution among Different Mosquito Vectors Is Affected by Tissue Localization and Host Species

“…Microorganisms 2024, 12, 545 2 of 13 Two bacteria have attracted great interest for their potential in the control of mosquitoborne diseases (MBDs): Wolbachia, obligate intracellular bacteria found in many insect species, and Asaia, Gram-negative bacteria also widely distributed in insects [4][5][6].…”