DIRECT IDENTIFICATION AND TYPING OF MYCOBACTERIUM-TUBERCULOSIS BY PCR

We have developed a rapid PCR assay that types strains of Mycobacteriu m tuberculosis by generating distinct DNA fingerprints directly from p rimary cultures. This assay allows strain identification analogous to that achieved by the standard restriction fragment length polymorphism method, and fingerprints are obtained in less than 8 h. This assay do es not require subculturing, DNA purification, restriction digestion, Southern blotting, or nucleic acid hybridization. Rapid and precise id entification of M. tuberculosis strains permits immediate molecular ep idemiologic studies. The assay can be converted to a computer-automate d system by employing fluorescently labeled PCR primers and the Perkin -Elmer DNA sequencer so that unknown-specimen fingerprints are identif ied by computer comparison to a database of M. tuberculosis strain fin gerprints.