Detection of human enteric viral genes in a non-native winter crane fly, Trichocera maculipennis (Diptera) in the sewage treatment facilities in Antarctic stations

Abstract

Abstract Background The Antarctic environment is susceptible to the introduction of non-native species due to its unique ecosystem, which has evolved under geographical isolation and extreme climatic conditions over an extended period. The non-native winter crane fly, Trichocera maculipennis, which was recently introduced to maritime Antarctica, is likely to pose a serious threat to the Antarctic ecosystem. In this study, the possibility of the mechanical transmission of viruses was evaluated. Methods The possibility of the mechanical transmission of viruses was evaluated using next-generation sequencing (NGS), quantitative polymerase chain reaction (qPCR), and virus isolation methods from T. maculipennis (Tm)-related samples (Tm body-wash fluid and Tm homogenate) collected from habitats and sewage treatment facilities located at three research stations in Antarctica. Results Our findings revealed the presence of human adenovirus (AdV) and human endogenous retrovirus (HERV) in Tm-related samples through virome analysis. Notably, these viruses are commonly detected in human feces. In addition, we identified pepper mild mottle virus (PMMoV) and cucumber green motortle mosaic virus (CGMMV), which are known indicators of enteric viruses, in all Tm-related samples. It is postulated that these viruses originated from wastewater, as evidenced by their detection in the wastewater samples. However, the minute quantities of AdV and HERV genomes detected in Tm-related samples through qPCR, coupled with the observed non-viability of AdV, indicate that T. maculipennis has limited potential for mechanical transmission. Conclusions Our study represents the first evaluation of the potential risk of non-native species serving as vectors for pathogens in Antarctica despite the relatively low quantities of detected viruses. This study provides valuable insights for further risk assessments of non-native species that are newly introduced or are likely to be introduced to Antarctica due to climate change or increased human activity.