Abstract
Mycoplasma ovipneumoniae poses a major threat to sheep respiratory health, contributing to significant economic losses in farming communities. In this study, we isolated a novel strain, IM-DMQ, from a Hu sheep in Inner Mongolia that exhibited pulmonary adenomatous-like lesions, which is an uncommon pathological manifestation for this pathogen. The complete genome was sequenced using a hybrid Nanopore and Illumina approach, revealing a 1,039,804 bp circular chromosome with a GC content of 29.15%, encoding 1529 genes. Functional annotation highlighted genes involved in essential metabolic processes and potential virulence mechanisms. Comparative genomic analysis demonstrated that IM-DMQ shares the closest ancestry (ANI: 98.3%) with the Chinese strain NXNK2203, while structural variations and 14 unique genes distinguished it from other global strains. Furthermore, microbial community profiling of the original lung tissue revealed a co-infection background involving multiple bacterial pathogens, offering an etiological context for the severe disease presentation. These results provide the first complete genomic resource for an M. ovipneumoniae strain from Inner Mongolia associated with unusual pulmonary pathology, offering insights into its genetic diversity and supporting the future development of targeted diagnostics and vaccines for regional disease control.