Chasing Waterborne Pathogens in Antarctic Human-Made and Natural Environments, with Special Reference to spp.

Waterborne pathogenic diseases are public health issues, especially for people staying in remote environments, such as Antarctica. After repeated detection of by PCR from the shower room of Syowa Station, the Japanese Antarctic research station, we wanted to understand the occurrence of waterborne pathogens, especially , in the station and their potential sources. In this study, we analyzed water and biofilm samples collected from the water facilities of Syowa Station, as well as water samples from surrounding glacier lakes, by 16S rRNA gene-based amplicon sequencing. For spp., we further attempted to obtain a detailed community structure by using genus-specific primers. The results showed that potentially pathogenic genera were mostly localized in the station, while spp., spp., and spp. were also widely distributed in lakes. Genus-specific analysis of spp. within the lake environments confirmed the presence of diverse amplicon sequence variants (ASVs) that were distinctly different from the ASVs detected in the station. The majority of the ASVs inhabiting Antarctic lake habitats were phylogenetically distinct from known species, whereas the ASVs detected in the human-made station tended to contain ASVs highly similar to well-described mesophilic species with human pathogenicity. These data suggest that unexpected diversity exists in remote Antarctic cold environments and that environmental differences (e.g., temperature) in and around the station affect the community structure. We comprehensively examined the localization of potential waterborne pathogens in the Antarctic human-made and natural aquatic environment with special focus on spp. Some potential pathogenic genera were detected with low relative abundance in the natural environment, but most detections of these genera occurred in the station. Through detailed community analysis of spp., we revealed that a variety of spp. was widely distributed in the Antarctic environment and that they were phylogenetically distinct from the described species. This fact indicates that there are still diverse unknown spp. in Antarctica, and this genus encompasses a greater variety of species in low-temperature environments than is currently known. In contrast, amplicon sequence variants closely related to known spp. with reported pathogenicity were almost solely localized in the station, suggesting that human-made environments alter the community.