Identification of two clinical isolates of Mycobacterium intracellulare / 中国人兽共患病学报

ABSTRACT

To identify the species of Mycobacterium clinical isolates by molecular biology techniques,six clinical isolates which were preliminarily recognized as Mycobacterium tuberculosis by the TCH and PNB culture methods were selected in this study.PCR was applied to amplify the oxyR-ahpC interval resistant-zone(intergenic region) and the length of PCR product in four strains was the same as that of H37Rv,while the length in the other two strains was different from that of H37Rv but same as Mycobacterium intracellulare 95002.With sequencing and on-line homology comparison with H37Rv,U18263 and U71061,the DNA sequence of oxyR-ahpC intergenic region displayed a 99% homology with Mycobacterium intracellulare U71061 and an 84% homology with Mycobacterium tuberculosis H37Rv.In addition,the results of hsp65 PCR-restriction fragment length polymorphism analysis and multi-locus PCR amplification in the two strains were identical with those of Mycobacterium intracellulare 95002.These two clinical isolates which were preliminarily recognized as Mycobacterium tuberculosis by PNB and TCH culture methods were finally identified as Mycobacterium intracellulare.Results predicted that the application associated with various techniques of molecular biology would provide a faster,easier and more correct way for the species identification of Mycobacterium.