Ureaplasma miroungigenitalium sp. nov. isolated from northern elephant seals (Mirounga angustirostris) and Ureaplasma zalophigenitalium sp. nov. isolated from California sea lions (Zalophus californianus).

Novel ureaplasma strains have been isolated from the genital tract of both sexes of northern elephant seals (Mirounga angustirostris; six strains) and California sea lions (Zalophus californianus; five strains) stranded along the Central California coast, USA. These strains were phenotypically and genetically characterized and compared to other seven known Ureaplasma species. All novel ureaplasma strains hydrolysed urea, but did not metabolize arginine, and all were isolated and propagated using PPLO medium supplemented with urea under aerobic, microaerophilic, and anaerobic atmospheric conditions at +35-37 °C. Transmission electron microscopy revealed typical mollicute cellular morphology. Molecular characterization included assessment of the following genetic loci: 16S rRNA, the 16S-23S ITS, 23S rRNA, rpoB, ftsH, tufB, rpoC, fusA and ureC. Complete 16S rRNA gene sequence analysis of these novel Ureaplasma species indicated that they were most closely related to each other with nucleotide identity 99.87 % and ≤93.08 % related to other known Ureaplasma species. The results of nucleotide analysis of the sequenced housekeeping genes revealed 71.68-93.02 % similarity to corresponding genes of other known Ureaplasma species. The multi-locus genetic characterization and the phylogenetic analysis of the 16S rRNA and rpoB genes of these Ureaplasma species clearly demonstrated their novelty and, reflecting their host specificites, the name Ureaplasma miroungigenitalium sp. nov. is proposed for the Ureaplasma species isolated from northern elephant seals, the type strain is ES2783-GENT (=DSM 24842T=ATCC BAA-2460T), and the name Ureaplasma zalophigenitalium sp. nov. is proposed for the Ureaplasma species isolated from California sea lions, the type strain is CSL7644-GENT (=DSM 24843T=ATCC BAA-2262T).