Mycobacterium shigaense sp. nov., a slow-growing, scotochromogenic species, is a member of the Mycobacterium simiae complex.

Among non-tuberculous mycobacteria (NTM), the Mycobacterium simiae complex is one of the largest groups, consisting of 18 species of slow-growing mycobacteria. In 2009, a case of NTM-associated infectious skin disease was reported in Shiga Prefecture, Japan. The patient presented with scattered nodules on the chest, back and extremities, and an M. simiae-like organism was isolated from skin biopsy specimens obtained from one of these lesions. Based on several assessments, including multiple-gene analyses, biochemical characterization and drug susceptibility testing, we concluded that this isolate represented a novel species of NTM, and proposed the name 'Mycobacterium shigaense'. Since 2009, five more cases of NTM-associated infectious disease in which there was a suspected involvement of 'M. shigaense' have been reported. Interestingly, four of these six cases occurred in Shiga Prefecture. Here we performed multiple-gene phylogenetic analyses, physiological and biochemical characterization tests, drug susceptibility tests, and profiling of proteins, fatty acids and mycolic acids of eight clinical isolates from the six suspected 'M. shigaense' cases. The results confirmed that all of the clinical isolates were 'M. shigaense', a slow-growing, scotochromogenic species. Here M. shigaense is validly proposed as a new member of the M. simiae complex, with the type strain being UN-152T (=JCM 32072T=DSM 46748T).

ISOLATION AND IDENTIFICATION OF AN ENDOPHYTIC FUNGUS PRODUCING PACLITAXEL FROM TAXUS WALLICHIANA VAR MAIREI.

The objective of this study was to isolate endophytic fungi producing paclitaxel from yew for the purpose of paclitaxel manufacture. Surface sterilized bark of Taxus wallichiana var. mairei was used as source material and potato dextrose agar culture medium was used in isolation of endophytic fungi. Fungal cultures were extracted with a mixture of chloroform / methanol (1:1, v/v) and the paclitaxel in the extracts was determined and authenticated with LC-MS. An endophytic fungus that produced paclitaxel was identified by ITS rDNA and 26S D1/D2 rDNA sequencing. The results showed that a total of 435 endophytic fungal strains were isolated from T. wallichiana var. mairei and purified. Only one of these strains produced paclitaxel and it belongs to Fusarium. The paclitaxel productivity in whole PDB culture and that in spent culture medium from this strain is 0.0153 mg/L and 0.0119 mg/L respectively. The paclitaxel content in dry mycelium is 0.27 mg/kg. This isolated endophytic fungus produced paclitaxel at a considerable level and shows potentiality as a producing strain for paclitaxel manufacture after strain improvement.

El objetivo de este estudio fue aislar hongos endofíticos productores de paclitaxel a partir de tejo con el propósito de fabricar paclitaxel. Se utilizó la superficie de la corteza esterilizada de Taxus wallichiana var. mairei como material de origen y dextrosa de patata en medio de cultivo de agar para el aislamiento de hongos endófitos. Los cultivos de hongos se extrajeron con una mezcla de cloroformo / metanol (1:1, v/v) y el paclitaxel en los extractos se determinó y autentificó con LC-MS. Un hongo endófito que produjo paclitaxel fue identificado por su ADNr 26S y secuenciación D1/D2 ADNr. Los resultados mostraron que un total de 435 cepas de hongos endófitos se aislaron y purificarón a partir de T. wallichiana var. mairei. Solo una de estas cepas produce paclitaxel y pertenece a Fusarium. La productividad del cultivo de paclitaxel procedente de esta cepa es 0,0153 mg/L y 0,0119 mg/L, respectivamente. El contenido de paclitaxel en micelio seco es 0,27 mg/kg. Este aislado de hongos endófitos produjo paclitaxel a un nivel considerable y muestra potencial como cepa para la fabricación de paclitaxel después de llevar a cabo una mejora de las cepas.