Two novel Gram-stain-negative, Oxidase-positive, catalase-negative, aerobic, non-motile and coccus-shaped bacterial strains (ZJ142T and ZJ171) were isolated from the respiratory tract of marmots collected from Yushu Tibetan Autonomous Prefecture (Altitude: 3600 m; N: 33°13'57'', E: 97°1'11'') in Qinghai Province. The 16S rRNA genes of strains ZJ142T and ZJ171 are most similar to Moraxella porci DSM 25326T (99.04%). The phylogenetic tree based on the 16S rRNA gene and phylogenomic tree based on 700 single-copy core genes indicated that strains ZJ142T and ZJ171 formed a distinct clade within the genus Moraxella. Two novel strains exhibiting Orthologous Average Nucleotide Identity values (ANI) ≤ 77.0% and digital DNA-DNA hybridization values (dDDH) ≤ 25.4% within the genus Moraxella affirmed their distinctiveness. The dDDH and ANI between strains ZJ142T and ZJ171 were 73.3% and 97.1%, respectively. Compared to other species in the genus Moraxella, both strains have similar colony morphology and growth conditions, and are capable of hydrolyzing esculin. Based on the phenotypic, phylogenetic, and physiological results, the two strains were classified as a novel species of the genus Moraxella, for which we proposed the name Moraxella marmotae sp. nov. (type strain ZJ142T = GDMCC 1.3113T = JCM 35324T). In type strain ZJ142T, we predicted biosynthetic gene clusters of lipooligosaccharide (LOS), pili and nitrate reductase and other virulence genes. Considering the respiratory source of our isolates and the best known pathogen in genus Moraxella, Moraxella catarrhalis, a well-known human respiratory pathogen, Moraxella marmotae sp. nov. may be a potential pathogen.
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