Drug Susceptibility Test of Mycobacterium tuberculosis: Analysis of 217 Clinical Isolates in Tibet

OBJECTIVE To understand the susceptibility to antituberculous agents for patients with primary and acquired drug resistance of Mycobacterium tuberculosis. METHODS M. tuberculosis positive sputum samples were collected from Jun to Dec 2006. Ameliorative Lowenstein-Jensen culture medium was used to detect bacillus-positive specimen of pulmonary tuberculosis by typing using PNB and TCH. Totally 217 samples were confirmedtobe positive by culturing. Drug susceptibility test against streptomycin (SM),isoniazid (INH),rifampicin (RFP) and ethambutol (EMB) was conducted. RESULTS The total drug resistance rate was 65.90%,the initial drug resistance rate was 39.81% and the initial multi-drug resistance rate was 16.67% ;the acquired drug resistance rate was 91.74%,and the acquired multi-drug resistance rate was 74.31%. The main causes of drug resistance were irregularit of treatment at beginning and preterm stop of the freatment course by patients own selves,which accounted for 71.6%. CONCLUSIONS The drug resistance of M. tuberculosis is caused by irregular treatment,so the key to prevent and control drug resistance is rational and whole-course treatment.