Abstract: Objective  To evaluate the value on rDNA sequencing of 16S-23S internal transcription space (ITS) and DNA microarray based on 16S rDNA for the rapid identification of mycobacterial species. Methods   21 mycobacterium reference strains and 50 clinical isolates were simultaneously identified by DNA sequencing and DNA microarray. Results  Of 21 mycobacterium reference strains, 18 were identified correctly at species level by DNA sequencing.  M.africanum and  M.tuberculosis strains were identified as M.tuberculosis complex, and M.marinum strain was identified as M.marinum/M.ulcerans. 16 strains were identified correctly by DNA microarray, but  1 M.gastri strain was identified as M.kansasii, 3 strains were absent of the specific probes in the microarray. Of 50 clinical isolates, 47 were consistent by DNA sequencing and DNA microarray, and one M.lentiflavum isolates was not identified by DNA microarray due to the absence of the specific probe. Conclusion  DNA microarray was a specific, accurate method for the rapid identification of most clinically relevant mycobacteria.

Key words: Mycobacterium, Polymerase chain reaction, Oligonucleotide array sequence analysis