DIFFERENTIATION BETWEEN MYCOBACTERIUM-TUBERCULOSIS AND MYCOBACTERIUM-AVIUM BY AMPLIFICATION OF THE 16S-23S RIBOSOMAL DNA SPACER

Differentiation between Mycobacterium tuberculosis and M. avium is hel pful for the treatment of disseminated mycobacterial infection in AIDS patients. This can traditionally be done by time-consuming biochemica l tests or with Accuprobe. Previously, PCR restriction enzyme analysis (PCR-REA) of the 16S-23S rRNA gene spacer was shown to be able to ide ntify a limited number of strains of Mycobacterium. In this study the method was improved by using more specific primers and was tested with 50 clinical isolates of M. tuberculosis and 65 clinical isolates of M . avium complex. Probes specific to the spacers of M. tuberculosis and avium were also tested. Both M. tuberculosis and M. avium could be re liably identified either by PCR-REA or by PCR-hybridization, with the results completely agreeing with those obtained by biochemical tests a nd with the Accuprobe, respectively. The method may therefore be usefu l as an alternative in-house method for identification of the bacteria .