Drug Resistance Detection in Mycobacterium Tuberculosis

MDR cases of tuberculosis are increasing and they are difficult to treat. This study was conducted to assess prevalence of drug resistance in Mycobacterium tuberculosis. Study comprises of 67 sputum specimen received for Mycobacterium tuberculosis (MTB) culture. Culture was done in Middlebrook broth using BacT Alert 3D automated culture system. The study period was from Dec 2018 to Nov 2019. Out of these MTB was grown in 31 (46.27 %) cases. The first line sensitivity testing was done in liquid culture media (BacT Alert3D) against Isonizid, Rifampicin, Ethambutol, Streptomycin. Isonizid and Rifampicin resistance was seen in 3 (9.68 %) cases. Only Isonizid resistance was seen in 9 (29.03 %) cases. This indicates that multidrug resistance is present to the tune of 9.68 % while monoresistance to isonizid is more common in 29.03 %. Monoresistance to rifampicin was not observed. Resistance to ethambutol and streptomycin was not observed in the present study. The advantage of doing Drug susceptibility testing in liquid media over solid media is speed and the results can be obtained within 15 days as compared to over 4 weeks when tested in solid media. Rifampicin resistance can be considered as a marker for labeling the strain as MDR.