Biodiversity and emerging infectious threats: the microbial dark matter of Southwest China

Southwest China is a global biodiversity hotspot, and its complex and diverse ecosystems harbor vast amounts of "microbial dark matter." This paper systematically examines the distribution characteristics of microbial dark matter in hosts such as arthropods, mammals, and birds, as well as in environments including soil, hot springs, and high-altitude lakes, with a particular focus on the cross-species transmissibility and pathogenic potential of emerging pathogens. Research indicates that new microbial species in the Southwest exhibit significant geographic concentration and host specificity: Yunnan Province is a core hotspot, while the Tibet Autonomous Region contributes a wealth of microbial resources due to its extreme environments, with arthropods and mammals accounting for the highest proportion of novel species. Regarding public health risks, eight novel pathogens with evidence of human infection have been identified, spanning the three major groups of viruses, bacteria, and parasites. The cross-species transmission potential of some pathogens (such as DPRV rhabdovirus, PPV arenaviridae, Luxi hantavirus, Banna virus and a novel Babesia species) has been confirmed through serological surveys or molecular testing. Deepening the exploration of microbial dark matter and risk early warning in this region will provide critical scientific support for public health safety monitoring.