Ecological insights into the cross-domain microbiome interactions in the hematophagous bat Desmodus rotundus

Background: Bats are recognised as reservoirs for a wide range of microorganisms, including viruses, bacteria, fungi, and parasites, some of which are of zoonotic concern. The common vampire bat (Desmodus rotundus) is particularly important due to its hematophagous feeding behaviour and ecological adaptability, both of which enhance its potential for cross-species pathogen transmission. Despite its well-established relevance to public health, the microbial communities associated with D. rotundus remain poorly characterised. This study aimed at investigating the composition, diversity, and interactions of prokaryotic, eukaryotic, and viral communities, alongside feeding sources, using high-throughput sequencing in 27 D. rotundus individuals from a rural area in Casanare, eastern Colombia. Results: We analysed a total of 81 samples (blood, faeces, and oral swabs) using long-read amplicon sequencing of the 16S- and 18S-rRNA genes and viral metagenomics via Oxford Nanopore Technologies. The microbial profiles revealed highly diverse assemblages, encompassing a wide range of bacterial, fungal, eukaryotic parasites, and viral taxa, with significant variation in community structure and diversity metrics across the three sample types collected from each bat. Taxa of public health concern were detected, including Enterococcus faecalis, Mycoplasma spp. Acanthamoeba spp. and viruses from the families Coronaviridae, Retroviridae, and Circoviridae. Correlation analyses suggested potential intra- and inter-domain interactions and co-occurrence dynamics among these microbes. Additionally, feeding source profiling, based on vertebrate assignments from faeces and swab samples, indicated evidence of livestock consumption, suggesting possible transmission pathways between bats and domestic animals. Conclusions: The detection of multiple co-occurring pathogens across distinct sample types, coupled with their association with feeding sources, highlights the role of D. rotundus as a functionally specialised reservoir capable of harbouring and potentially disseminating zoonotic microbes. This study provides new insights into the cross-domain microbial ecology of hematophagous bats and underscores the need to integrate microbial community profiling with host behavioural data to enhance surveillance and mitigation strategies for zoonotic disease transmission.