In:
Journal of Clinical Microbiology, American Society for Microbiology, Vol. 36, No. 1 ( 1998-01), p. 139-147
Abstract:
Interspecific polymorphisms of the 16S rRNA gene (rDNA) are widely used for species identification of mycobacteria. 16S rDNA sequences, however, do not vary greatly within a species, and they are either indistinguishable in some species, for example, in Mycobacterium kansasii and M. gastri , or highly similar, for example, in M. malmoense and M. szulgai . We determined 16S-23S rDNA internal transcribed spacer (ITS) sequences of 60 strains in the genus Mycobacterium representing 13 species ( M. avium , M. conspicuum , M. gastri , M. genavense , M. kansasii , M. malmoense , M. marinum , M. shimoidei , M. simiae , M. szulgai , M. triplex , M. ulcerans , and M. xenopi ). An alignment of these sequences together with additional sequences available in the EMBL database (for M. intracellulare , M. phlei , M. smegmatis , and M. tuberculosis ) was established according to primary- and secondary-structure similarities. Comparative sequence analysis applying different treeing methods grouped the strains into species-specific clusters with low sequence divergence between strains belonging to the same species (0 to 2%). The ITS-based tree topology only partially correlated to that based on 16S rDNA, but the main branching orders were preserved, notably, the division of fast-growing from slowly growing mycobacteria, separate branching for M. simiae , M. genavense , and M. triplex , and distinct branches for M. xenopi and M. shimoidei . Comparisons of M. gastri with M. kansasii and M. malmoense with M. szulgai revealed ITS sequence similarities of 93 and 88%, respectively. M. marinum and M. ulcerans possessed identical ITS sequences. Our results show that ITS sequencing represents a supplement to 16S rRNA gene sequences for the differentiation of closely related species. Slowly growing mycobacteria show a high sequence variation in the ITS; this variation has the potential to be used for the development of probes as a rapid approach to mycobacterial identification.
Type of Medium:
Online Resource
ISSN:
0095-1137
,
1098-660X
DOI:
10.1128/JCM.36.1.139-147.1998
Language:
English
Publisher:
American Society for Microbiology
Publication Date:
1998
detail.hit.zdb_id:
1498353-9
SSG:
12
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