Nocardia shimofusensis sp. nov., isolated from soil, and Nocardia higoensis sp. nov., isolated from a patient with lung nocardiosis in Japan.

Three actinomycete strains isolated from soils and one strain isolated from a patient with lung nocardiosis in 1999 and 2001 in Japan have been provisionally assigned to the genus Nocardia on the basis of morphological criteria. These isolates were further investigated to determine their specific taxonomic status. Detailed chemotaxonomic characterization and 16S rRNA gene sequence analysis of these isolates confirmed that they belong to the genus Nocardia. The 16S rRNA gene sequences of the four strains were most similar to that of Nocardia farcinica. However, the sequence similarity values between these four strains and N. farcinica were <98.9 %. These four strains were susceptible to 5-fluorouracil, and they have the ability to decompose urea, which is a very characteristic trait. Furthermore, DNA-DNA relatedness data revealed that IFM 10311(T), IFM 10312 and IFM 10313 comprise a single novel species of Nocardia, that IFM 10084(T) represents another novel species of Nocardia and that these two novel species could be distinguished from N. farcinica. The names Nocardia shimofusensis sp. nov. and Nocardia higoensis sp. nov. are proposed, with IFM 10311(T) (=NBRC 100134(T)=JCM 12122(T)=DSM 44733(T)) and IFM 10084(T) (=NBRC 100133(T)=JCM 12121(T)=DSM 44732(T)) as the respective type strains.