Rapid Detection of Mycobacteria usin Mycobacteria Growith Indicator tube(MGIT)and Ogawa Media

Kwon, Oh Gun; Cho, Hyun Mi; Jang, In Ho; Uh, Young; Yoon, Kap Jun

Abstract

BACKGROUND: As many as several weeks of incubation may be necessary for the recovery of mycobacteria when conventional culture media are used. Previous studies evaluating Mycobacteria Growth Indicator Tube (MGIT) as a rapid for the growth and detection of mycobacteria from clinical specimens have been reported. We compared MGIT with Ogawa media for the recovery of mycobacteria from clinical specimens.
METHODS
Ninety nine clinical specimens received in the laboratory of Wonju Christian Hospital from June to September 199 were used for this study. The specimens from nonsterile body sites were digested, decontaminated, and concentrated, for culture and Ziehl-Neelsen stain, and specimen were inoculated onto MGIT tube and 3% Ogawa egg medium, and cultured for 8 weeks.
RESULTS
Of the 38 specimens culture-positive for mycobacteria, 3 grew isolates in MGIT medium only, 8 grew isolates in Ogawa media only, and 27 grew isolates in both media. Mean (median, range) times to detection of mycobacteria were 13.7 (5.5, 2-48) days with MGIT and 19.6 (18, 13-37) days with Ogawa (P>0.05). The number recovered with MGIT plus Ogawa media was 24 (63.2%) within 14 days of receipt of specimen, and 31 (81.6%) within 21 days. The contamination rates were 31 % for MGIT and 1 % for Ogawa media.
CONCLUSIONS
MGIT appears useful to quickly detect and identify mycobacteria from clinical specimens. However, because the number of culture-positive specimen in MGIT was not greater than those recovered with Ogawa media, MGIT should be used in combination with solid media to reduce turnaround times and increase the isolation rate.