Microcolony observation for rapid detection and identification of cultures of Mycobacterium tuberculosis

219 sputa were seeded on Kuang's agar plates. A total of 112 isolates of Mycobacterium tuberculosis were detected in 219 specimens. Of these 112 isolates, 104 (92.8%) were detected in Kuang's agar media and 108 (96.4%) were detected by microcolony observation. The detection time of microcolony observation and culture method needed 11 and 18.6 days respectively. The detection time of microcolony method is much shorter (P < 0.001). The results of conventional tests of different species of Mycobacterium and microcolony differentiation were identical in 99% of isolates of Mycobacterium tuberculosis.