Correlation between Microscopic Observation Drug Susceptibility culture, Ziehl-Neelsen stain and Lowenstein-Jensen culture of sputum in suspected pulmonary tuberculosis patients

Ziehl-Neelsen stain is an initial route in diagnosis of pulmonary tuberculosis. Some studies show the sensitivity and specificity of the methods of liquid media culture in rapid diagnosis of the disease. In this study, we evaluated the correlation between Microscopic Observation Drug Susceptibility culture, Ziehl-Neelsen stain and Lowenstein-Jensen culture of sputum in suspected pulmonary tuberculosis patients. This was a descriptive study with the technique of observational-interview type.One hundred patients from Masih Daneshvari hospital were considered as pulmonary TB suspects. One early morning sputum sample was obtained from each patient and used for Ziehl-Neelsen stain, culture on Lowenstein-Jensen medium and MODS culture for drug susceptibility testing. On sputum examination, 40% of patients were smear positive by Ziehl-Neelsen stain, while 30% had positive sputum culture for Mycobacterium tuberculosis in Lowenstein-Jensen medium and 47% had positive MODS culture. This research showed a significant and direct correlation between MODS culture with Lowenstein-Jensen media (r=+0.39, P<0.0001). There was a significant association and a significant and reverse correlation between MODS culture with pleural effusion(r=-0.23 P<0.05). Multidrug resistance was observed in 55% of patients. Prevalence of positivity of these diagnostic methods among MDR patients was lower. There was a significant and direct correlation between MDR diseases with MODS culture.(r=+0.96 P<0.0001) due to increasing of MDR tuberculosis, rapid determination of resistance pattern is very important which is possible by using MODS culture method. However, since lower positivity of MODS culture is obtained in MDR patients, Lowenstein-Jensen culture method should be done as complementary method in suspected pulmonary tuberculosis patients.