ABSTRACT
A thorough phenotypic and genotypic analysis of 150 strains belonging to the Mycobacterium terrae complex resulted in the identification of a number of previously unreported sequevars (sqvs) within the species known to belong to the complex. For the species Mycobacterium arupense, three sqvs were detected in the 16S rRNA gene, six sqvs in the hsp65 gene and 15 sqvs in the rpoB gene; in Mycobacterium senuense two sqvs were present in each of the three genetic regions; in Mycobacterium kumamotonense four, two and nine sqvs were found, respectively, and in M. terrae three, four and six sqvs were found, respectively. The inappropriate inclusion of Mycobacterium triviale within the M. terrae complex was confirmed. The limited utility of biochemical tests and of mycolic acid analyses for the differentiation of the members of M. terrae complex was also confirmed. The survey allowed the recognition of three previously undescribed species that were characterized by unique sequences in the 16S rRNA, hsp65 and rpoB genes. Mycobacterium engbaekii sp. nov. (proposed previously 40 years ago but never validly published) was characterized by pink photochromogenic pigmentation and rapid growth; phylogenetically it was related to Mycobacterium hiberniae. The type strain of this species, of which eight strains were investigated, is ATCC 27353(T) (â=âDSM 45694(T)). A cluster of 24 strains was the basis for the description of Mycobacterium heraklionense sp. nov., which has an intermediate growth rate and is unpigmented; nitrate reductase activity is typically strong. Closely related to M. arupense with respect to the 16S rRNA gene, M. heraklionense sp. nov. could be clearly differentiated from the latter species in the other genetic regions investigated. The type strain is NCTC 13432(T) (â=âLMG 24735(T)â=âCECT 7509(T)). Mycobacterium longobardum sp. nov., represented in the study by seven strains, was characterized by a unique phylogenetic location within the M. terrae complex, clearly divergent from any other species. The type strain is DSM 45394(T) (â=âCCUG 58460(T)).
Subject(s)
Nontuberculous Mycobacteria/classification , Phylogeny , Bacterial Typing Techniques , DNA, Bacterial/genetics , Genes, Bacterial , Molecular Sequence Data , Mycolic Acids/analysis , Nontuberculous Mycobacteria/genetics , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNAABSTRACT
Five independent strains, isolated from clinical samples but probably not responsible for disease, revealed phenotypic and genotypic features that appeared to exclude their belonging to any of the recognized Mycobacterium species. The strains, which are non-pigmented rapid growers, presented a cell-wall lipid pattern resembling those of Mycobacterium brumae and Mycobacterium fallax. Sequencing of the 16S rRNA, hsp65 and rpoB genes and the 16S-23S rRNA gene internal transcribed spacer (ITS) revealed that the strains are clearly distinct from every other Mycobacterium species. While the 16S rRNA and rpoB genes were characterized by a single sequevar, two sequevars were detected in hsp65 and three in the ITS. The divergence shown in the latter region was striking, in which only two short regions (less than 150 bp in all) were comparable with other mycobacteria, apart from Mycobacterium monacense and Mycobacterium gilvum. The PCR restriction analysis pattern of the novel strains also differs from any reported to date. The name Mycobacterium insubricum sp. nov. is proposed for the novel species; the type strain is FI-06250(T) (=DSM 45132(T) =CIP 109609(T)).
Subject(s)
Mycobacterium/classification , Sputum/microbiology , Adult , Bacterial Proteins/genetics , Bacterial Typing Techniques , Base Composition , Base Sequence , DNA, Bacterial/analysis , DNA, Ribosomal Spacer/analysis , DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , Humans , Middle Aged , Molecular Sequence Data , Mycobacterium/genetics , Mycobacterium/isolation & purification , Mycobacterium/physiology , Mycobacterium Infections/microbiology , Nucleic Acid Hybridization , Phenotype , Phylogeny , Polymerase Chain Reaction/methods , RNA, Ribosomal, 16S/genetics , RNA, Ribosomal, 23S/genetics , Restriction Mapping , Sequence Analysis, DNA , Species Specificity , Young AdultABSTRACT
Mycobacterium arosiense is a newly described species. After noticing it was misidentified as Mycobacterium intracellulare by the commercial identification system GenoType CM (Hein, Nehren, Germany), we detected 4 such strains among 33 that were previously misidentified as M. intracellulare. Three more strains were found among unidentified mycobacteria not tested previously with GenoType. The first case of pulmonary disease due to M. arosiense is reported here, and the novel species, of which so far only one strain had been investigated, is further characterized.
Subject(s)
Lung Diseases/microbiology , Mycobacterium Infections/diagnosis , Mycobacterium/isolation & purification , Anti-Bacterial Agents/pharmacology , Germany , Humans , Male , Microbial Sensitivity Tests , Middle Aged , Mycobacterium/drug effects , Mycobacterium Infections/microbiology , Radiography, ThoracicABSTRACT
A new commercial system for rapid extraction of DNA, consisting of a card on which a drop of bacterial suspension is spotted, was evaluated with 43 mycobacterial strains. Once dried, a small disk of the seeded area was directly transferred in the amplification mixture. All the samples produced good quality amplification products which were satisfactorily sequenced.