The preliminary study on ununiformity of drug resistance of M.TB isolate d from multiple drug resistant tuberculosis patients The First Affilliated Hospital,Chongqing Medical University / 中国实用内科杂志

ABSTRACT

Objectives To study if there exists the ununi formity of drug resistance of mycobacterium tuberculosis (M.TB) isolated from MDR-TB patients .Methods One MDR-TB patient was chosen for this study a nd his sputum was cultured.The suspension of the culture was filtered through 8 0?m -pore-size membrane filter and single M.TB suspension was obtained.The single M.TB suspension was cultured on Lowsenstein Jensen (L-J) medium.24 of col onies were obtained and they were cultured respectively again to get pure strain s.The drug sensitivity test was carried out for these 24 pure strains of M.TB wi th Chinese standard method.H 37 Rv was taken as control.Results 1 strain (4 2%) was found to be susceptive to INH,22 strains ( 91 6%) resistant to low concentration INH (H 1 ),1 strain (4 2%) resistant to high concentration INH (H 10 ).2 strains (8 3%) were found t o be susceptive to RFP,2 strains (8 3%) resistant to low concentration RFP(R 50 ),20 strains (83 4%) resistant to high concentration RFP(R 250 ).We f ound 1 strain (4 2%) susceptive to SM,23 strains (95 8%) resistant to high concentr ation SM(S 100 ).All were susceptive to EMB.Conclusions The ununiformity of drug resistance exists among the M.TB isolated from the MDR-TB patients.Sensitive and resistant strains exist together,low and high concentration-drug-resistant strains coexi st in the same situation.The majority of M.TB is drug-resistant and only a few are still sensitive to low concentration- drug- resistant.