ABSTRACT
Objective To investigate the diagnostic value of microscopic observation drug susceptibility assay (MODS) in extrapulmonary tuberculosis. Methods MODS technology was constructed by using 24-well cell culture plate and liquid culture.Ziehl-Neelsen smear,Lowenstein-Jensen culture and MODS were used to detect Mycobacterium tuberculosis in 74 pleural fluid samples collected from patients with tuberculous pleurisy,63 cerebrospinal fluid samples collected from patients with tuberculous meningitis and 18 samples collected from non-tuberculosis suspects.The immunochromatography was used to distinguish Mycobacterium tuberculosis from nontuberculosis mycobacteria. The results of Ziehl-Neelsen smear, Lowenstein-Jensen culture and MODS were compared by x2 test.Results The positive rates of MODS,Lowenstein-Jensen culture and Ziehl-Neelsen smear were 58.1 ％ (43/74),18.9 ％ (14/74 ) and 6.8％ (5/74),respectively in tuberculous pleurisy patients; 54.0％(34/63),20.6％ (13/63) and 4.8％ (3/63),respectively in tuberculous meningitis patients.The positive rate of MODS technology was significantly higher than that of Lowenstein Jensen culture in tuberculous pleurisy patients (x2 =24.00,P＜0.01) and tuberculous meningitis patients (x2 =14.97,P ＜ 0.01). Each Mycobacterium obtained from MODS and Lowenstein-Jensen culture was identified as Mycobacterium tuberculosis by immunochromatography.All of the 18 pleural fluid and cerebrospinal fluid samples which collected from non-tuberculosis suspects were all negative detected by Ziehl-Neelsen smear,Lowenstein-Jensen culture and MODS.The median time to culture positive of MODS was 9 days in cerebrospinal fluid and 14 days in pleural fluid samples,which were both significantly shorter than that of Lowenstein-Jensen culture (31 days in both cerebrospinal fluid and pleural fluid samples). Conclusion Compared to conventional microbiological diagnosis methods,MODS is a rapid detection method of Mycobacterium tuberculosis with a higher positive detection rate,which is suitable for rapid diagnosis of extrapulmonary tuberculosis.