Environmental Drivers of Nontuberculous Mycobacteria in Tropical Freshwater Systems

ABSTRACT

Whilst microbial diversity still remains largely unexplored across environments and scales, microbial biogeography is shaped by edaphic and ecological drivers, and shifts in microbial community composition are frequently associated with host community structure and health. Nontuberculous mycobacteria represent a striking example of environmental microorganisms with opportunistic pathogenic potential. Unfortunately, understanding of their diversity and distribution in tropical freshwater environments remains limited, while such knowledge is crucial for predicting disease emergence and transmission. Here we aimed at (i) identifying microhabitat abiotic and biotic drivers influencing their diversity and distribution in French Guiana, (ii) comparing their diversity and distribution between French Guiana and Côte d'Ivoire, and (iii) examining co‐occurrences between mycobacterial communities in different environmental contexts. By deploying an eDNA‐based metabarcoding approach from tropical freshwater ecosystems, we suggest that their diversity and distribution are mainly driven by habitat type (urban vs. rural), sample type (water vs. sediment), and local abiotic factors such as phosphorus levels in sediments (with species‐specific effects). Moreover, we found a stratified distribution of mycobacteria depending on sediment texture (fine silts vs. coarse sand) and depth. Overall, we suggest that their ecological interactions may occur at the microhabitat level rather than following clear biogeographic patterns.