Characterization of the bacterial and fungal diversity in habitats of Corsica Island

Indoor environments may impact human health significantly since microbial diversity made of various bacteria, fungi, and other microorganisms constitutes the habitat's microbiome. These microorganisms originate from diverse sources, such as the environment, humans, and pets. Understanding such microbial diversity is crucial for assessing related health impacts. The aim of this study was to investigate bacterial and fungal microorganisms from different surfaces in a set of houses on Corsica Island (southeastern France). We conducted sampling and high-throughput sequencing of PCR-amplified microbial DNA from 40 habitats (eight different surfaces tested for each) located on diverse regions of the island. Following nucleic acid recovery, we performed PCR targeting V3-V4 regions of 16S rRNA for bacteria and ITS1 region for fungi. Bioinformatics processing allowed the identification of distinct microbial species and the analysis of their distribution. Our findings highlighted that the most represented bacterial genera in the Corsican homes tested were <i>Ralstonia</i> (16.9%), <i>Staphylococcus</i> (4.8%), <i>Corynebacterium</i> (2.7%), <i>Enhydrobacter</i> (6.8%), and <i>Methylorubrum</i> (6.0%). Regarding fungal diversity, the most common genera identified were <i>Dipodascaceae</i> (21.6%), <i>Rhodotorula</i> (10.9%), <i>Aspergillus</i> (8.9%), <i>Clavispora</i> (7.3%), and <i>Candida</i> (6.8%). Our results also showed differences in microbial composition among the habitats studied, while a higher bacterial and fungal diversity was observed in rural habitats and in those with pets.IMPORTANCEThis study provides valuable insights into the microbial diversity present in indoor environments of Corsican homes, specifically highlighting bacterial and fungal communities on various household surfaces. By identifying the predominant microbial genera and revealing differences linked to habitat characteristics, such as rural settings and pet ownership, this research enhances our understanding of how indoor microbial communities vary.