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Identification of Mycobacterium intracellulare by a polymerase chain reaction using species-specific primers
1Department of Bacteriology, National Institute of Health, Tokyo, Japan.
Setting:
The polymerase chain reaction (PCR) is a rapid and specific method used to amplify a certain DNA fragment. It is applicable to rapid diagnosis of mycobacterial infections. By use of species-specific primers, it is possible to identify mycobacteria by PCR. In this study, a newly constructed primer was tested for specificity for Mycobacterium intracellulare in the PCR.
Objective:
M. intracellulare is one of the most frequently found bacteria in opportunistic infection in AIDS, and rapid identification of this species is important. The purpose of this study was to construct a primer specific to this species as a suitable tool for identification.
Design:
PCR products of M. tuberculosis and M. intracellulare, obtained by using the primers YNP-1 and YNP-2, were sequenced and compared. They showed a difference in the base sequences. A sequence unique to M. intracellulare was used as the primer specific to this species. Various mycobacterial and non-mycobacterial DNAs were used as the primer specific to this species. Various mycobacterial and non-mycobacterial DNAs were used as the template to evaluate the specificity of the newly constructed primers, YNP-7 and YNP-8. Sputum samples were also examined by PCR using the primers.
Results:
In total 25 species of culture mycobacterial and non-mycobacterial strains and 76 sputum samples were tested by PCR. Only M. intracellulare DNA was amplified with PCR using the primers YNP-7/8.
Conclusion:
The specificity of the newly constructed primers for M. intracellulare was confirmed.