One Health Insights From Pteropus medius: Nipah Virus Spillover, Microbiota, and Antimicrobial Resistance.

Pteropus medius is a major reservoir of Nipah virus (NiV), a zoonotic pathogen responsible for recurrent fatal encephalitis outbreaks in Bangladesh. Human infections are primarily associated with consuming raw date palm sap contaminated with bat excreta. Beyond viral spillover, growing evidence suggests that bat-associated microbiota and guano are potential reservoirs of antimicrobial resistance (AMR), contributing to the environmental dissemination of resistant bacteria and resistance genes. This narrative literature review examined the relationship among NiV spillover, bat microbiota, and AMR within a One Health framework. A structured literature search was conducted using PubMed, Scopus, Web of Science, ScienceDirect, and Google Scholar to identify relevant peer-reviewed studies published between 2006 and 2025. The reviewed evidence indicates that Pteropus medius populations harbor clinically important resistant bacteria, including ESBL-(Extended-Spectrum Beta-Lactamase) producing Escherichia coli, Salmonella spp., and methicillin-resistant Staphylococcus spp. In addition, recent studies indicate that bat roosts near agricultural lands, wastewater discharge sites, and peri-urban settlements may facilitate bidirectional exchange of ARGs among wildlife, livestock, and humans. Habitat fragmentation, wastewater contamination, urbanization, agricultural intensification, and increased human-wildlife interactions were identified as major drivers facilitating both NiV spillover and AMR dissemination. Overall, the literature demonstrates a significant ecological association among anthropogenic environmental disturbance, zoonotic spillover risk, and the emergence of antimicrobial resistance in bat-associated systems. These findings highlight the importance of integrated One Health surveillance and environmental management strategies to mitigate future zoonotic and AMR threats in Bangladesh.