Evaluation of MODS for susceptibility testing of second-line drug in Mycobacterium tuberculosis / 中华检验医学杂志

ABSTRACT

Objective To test the drug susceptibilities in Mycobacterium tuberculosis by microscopic observation drug susceptibility(MODS)and evaluate the method for the detection susceptibility in second-line drugs.Methods To set up the MODS method.the drug susceptibilities of 4 second-line drugs in Mycobacterium tuberculosis were tested in 24 well plates.The test conditions were discussed.The resistance to protionamide(PTH),amikacin(AMK),capreomycin(CPM)and levofloxacin(LVF)of 60 MTB isolated from 2007 to 2008 in Shanghai Pulmonary Hospital were detected and compared with that of L-J method.The isolates were tested by minimum inhibitory concentration(MIC)method when the drug susceptibilities were not consistent.Results Among the 60 Mycobacterium tuberculosis clinical isolates.the results of drug susceptibility were confirmed by MODS,absolute concentration method and the accordance rate of PTH,AMK,CPM and LVF were 96.7%(58/60),98.3%(59/60),91.7%(55/60)and 96.7%(58/60),respectively.If the result of absolute concentration method was as the standard.the sensitivity.specificity.positive and negative predictive value as well as accuracy were 100%,87.5%,87.5%,100%and 96.7%in PTH;100%,90.0%,90.0%,100%and 98.3% in AMK;76.9%,95.7%,83.3%,93.8%,91.7% in CPM;100%,96.0%,83.3%,100% and 96.7% in LVF respectively detected by MODS assay.Conclusion MODS is a rapid and simple method for susceptibility testing of second-line drug in Mycobacterium tuberculosis.