Isolation and Identification of the Etiological Agent of Pulmonary Tuberculosis in Patients Visiting National Tuberculosis Center, Thimi, Bhaktpur

Abstract

During the study period of June 2005 to May 2006 a total of 200clinicallysuspectedsputum samples were examined by ZN staining and cultured in Ogawa medium.Primaryculture samples were subcultured in the LJ medium. The subcultures wereobserved for their cultural characters for 4 weeks and then subjected for biochemicaltests for their confirmation asM.tuberculosis.From the 200 subculturesNiacin,Nitratereduction, 68ºC labile catalase test and growth on PNB containing medium wasperformed. Out 200 samples 190 (95%), 189 (94.5%), 6 (3%) and 7 (3.5%) werepositive for Niacin, Nitrate reduction, 68ºC labile catalase and growth on PNBcontaining medium and 10 (5%), 11 (5.5), 194 (97%) and 193 (96.5%) were negativefor the respective tests. Out of 200 samples 189 (94.5%) were positive for Niacin and Nitrate reduction andnegative for 68ºC labile catalase and growth on PNB containing medium whichconfirms that they wereM. tuberculosis. Thus with the combination of above mentioned tests 189 (94.5%) out of 200 culturepositive were confirmed asM. tuberculosisand the rest may be MOTT. Biochemicaltests although time consuming is a very good alternative to new quick methods likePCR and NAA.