IDENTIFICATION OF MYCOBACTERIUM-TUBERCULOSIS COMPLEX, MYCOBACTERIUM-AVIUM AND MYCOBACTERIUM-INTRACELLULARE BY SELECTIVE NESTED POLYMERASE CHAIN-REACTION

A nested polymerase chain reaction (PCR) procedure was devised for ide ntification of mycobacteria. The outer reaction exploiting genus-speci fic sequences on the 16S rRNA gene was able to amplify specifically st rains of the genus Mycobacterium. The identification of Mycobacterium tuberculosis complex, Mycobacterium avium and Mycobacterium intracellu lare was accomplished by selective reamplification of the outer PCR pr oduct in three distinct inner amplifications exploiting species-specif ic primers mapping to a hypervariable region of mycobacterial 16S rRNA . Detection of mycobacteria, other than those for which species-specif ic primers were used, was accomplished by adding a supplementary genus -specific upper primer to one of the inner reactions. Specificity of a mplification was confirmed for clinical isolates and reference strains of different mycobacterial species with the exception of a M. intrace llulare type 7 strain which was recognized as M. avium. The amplificat ion protocol presented thus provides a reliable and cost-effective way for identification of clinically relevant mycobacteria. (C) 1995 Acad emic Press Limited