Nocardia sputorum sp. nov., an actinobacterium isolated from clinical specimens in Japan

Two novel actinobacteria, designated IFM 12276 T and IFM 12275, were isolated from clinical specimens in Japan, and their taxonomic positions were investigated using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strains IFM 12276 T and IFM 12275 have completely identical 16S rRNA gene sequences and were closely related to members of the genus Nocardia . The highest 16S rRNA gene sequence similarity was observed to Nocardia beijingensis (99.6 %) and Nocarida sputi (99.6 %), followed by Nocardia niwae (99.3 %) and Nocardia araoensis (99.3 %). The whole-cell hydrolysates of strains IFM 12276 T and IFM 12275 contained meso -diaminopimelic acid, arabinose and galactose. The acyl type of muramic acid was N -glycolyl. The predominant isoprenoid quinone was MK-8(H 4 , ω -cycl.) and the principal polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannosides. Strains IFM 12276 T and IFM 12275 contained mycolic acids that co-migrated with those from the type strain of N. niwae . These chemotaxonomic features corresponded to those of the genus Nocardia . Meanwhile, the differences in some phenotypic characteristics, along with the results of average nucleotide identity and digital DNA–DNA hybridization analyses, indicated that strains IFM 12276 T and IFM 12275 should be distinguished from the recognized species of the genus Nocardia . Therefore, these strains represent a novel species of the genus Nocardia , for which the name Nocardia sputorum sp. nov. is proposed. The type strain is IFM 12276 T (=NBRC 115477 T =TBRC 17096 T ).