Bacterial and fungal diversity in Anopheles larval habitats with different productivities

Anopheles gambiae mosquitoes develop in diverse aquatic habitats, where microbial communities influence oviposition, larval growth, and survival. This study characterized bacterial and fungal communities across Anopheles larval habitats of differing productivity in southern Ghana. Larval densities were monitored bi-weekly over 6 months. Water and larval samples were collected for bacterial (16S rRNA gene) and fungal (ITS) amplicon sequencing. Based on the consistency of Anopheles larval presence throughout the monitoring period, habitats were classified as high-productive (larvae present at every visit), low-productive (intermittent larval presence), or non-productive (larvae consistently absent). The study revealed that distinct microbial signatures were associated with habitat productivity. Linear discriminant analysis identified Paraclostridium bifermentans and Bacillus spp. as indicator taxa for high-productive habitats, while Acinetobacter variabilis and Lactococcus garvieae were associated with low-productive habitats. For fungi, Cladosporium halotolerans and Aspergillus penicillioides were the primary discriminant taxa associated with high-productive habitats, while Candida tropicalis and Pichia kudriavzevii characterized low-productive habitats. Beta-diversity analyses revealed significant differences in bacterial communities between productive and non-productive habitats (PERMANOVA, p = 0.006), whereas fungal communities showed no significant separation. These findings highlight an association between microbial assemblages and larval-habitat suitability and underscore the potential of microbiota-informed strategies to enhance vector surveillance and targeted larval control.