Next-Generation Sequencing in Practical Wildlife Disease Investigation: Metagenomic Insights into European Bison and Gazelle Mortality and Morbidity Events

Wildlife disease investigations require diagnostic methods capable of detecting diverse and previously unrecognized pathogens. Metagenomic next-generation sequencing (mNGS) was applied to samples from three Dorcas gazelles (Gazella dorcas osiris) affected by sudden mortality and four European bison (Bison bonasus) with respiratory disease or necrotic balanoposthitis (NBP). No dominant bacterial species was detected in gazelles. In European bison, respiratory disease was associated with Pasteurella multocida, whereas NBP samples were dominated by Porphyromonas levii and other anaerobes. Dorcas gazelle samples contained mainly Retroviridae-related sequences of undetermined pathogenic significance. Parapoxvirus-related annotations were not confirmed by PCR, suggesting non-specific or host-related sequence similarity. Macavirus-related sequences were consistent with previous PCR findings and enabled reconstruction of an approximately 51.1 kb fragment of a divergent gammaherpesvirus genome. These findings demonstrate the value of mNGS for wildlife disease investigation and genomic surveillance, while emphasizing the need for independent validation of metagenomic taxonomic assignments.