IDENTIFICATION OF MYCOBACTERIUM-INTRACELLULARE BY A POLYMERASE CHAIN-REACTION USING SPECIES-SPECIFIC PRIMERS

Setting: The polymerase chain reaction (PCR) is a rapid and specific m ethod used to amplify a certain DNA fragment. It is applicable to rapi d diagnosis of mycobacterial infections. By use of species-specific pr imers, it is possible to identify mycobacteria by PCR. In this study, a newly constructed primer was tested for specificity for Mycobacteriu m intracellulare in the PCR. Objective: M. intracellulare is one of th e most frequently found bacteria in opportunistic infection in AIDS, a nd rapid identification of this species is important. The purpose of t his study was to construct a primer specific to this species as a suit able 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 sequ ences. A sequence unique to M. intracellulare was used as the primer s pecific to this species. Various mycobacterial and non-mycobacterial D NAs were used as the template to evaluate the specificity of the newly constructed primers, YNP-7 and YNP-8. Sputum samples were also examin ed by PCR using the primers. Results: In total 25 species of cultured mycobacterial and non-mycobacterial strains and 76 sputum samples were tested by PCR. Only M. intracellulare DNA was amplified with PCR usin g the primers YNP-7/8. Conclusion: The specificity of the newly constr ucted primers for ill. intracellulare was confirmed.