[Rapid genetic identification system of mycobacteria]

Rapid colorimetric hybridization method was applied for the identification of mycobacteria and phylogenetic detection and identification system of mycobacteria of polymerase chain reaction method was designed. Quantitative DNA-DNA hybridization in microdilution plate was used to identify 22 mycobacterial species. This method could identify 90% (178 among 194 trials) of clinical isolates within 3 hr. Ten percent of clinical isolates did not belong to any of the established 22 species. Through this work, we found Mycobacterium abscessus is genetically independent from M. chelonae and proposed M. abscessus as a distinct species. M. pregrinum had been classified as M. fortuitum, however, it was also found as a independent species. Thus the name M. peregrinum was officially revived and acquired the taxonomic position. Highly sensitive genetic detection system of mycobacteria was designed by using polymerase chain reaction (PCR) method. Common mycobacterial sequence of 16S ribosomal RNA gene was first amplified by a single pair of PCR primers from staining negative sputum and the amplified DNA was identified by species specific DNA probe because the amplified fragment contained species specific sequence.