The study of bacteriophage based assay detecting Ethambutol resistance in clinical isolates of Mycobacterium tuberculosis / 中华传染病杂志

ABSTRACT

Objective To set up and evaluate the method of Phage Amplified Biologically Assay (PhaB) in the rapid detection of detection of Ethambutol resistance. Methods To detect the EMB resistance of 102 clinical isolates of Mycobacterium tuberculosis by PhaB and compare it with the results of absolute concentration method. The minimum inhibitory concentration (MIC) was detected for all discrepancy isolates. Results Of all 102 strains in Mycobacterium tuberculosis clinical isolates, 82 strains were EMB susceptible and 20 strains were EMB resistant by PhaB method, while 77 strains were EMB susceptible and 25 strains were EMB resistant by absolute concentration method. 74 of 102 strains were EMB susceptible and 17 strains were EMB resistant by both methods. The concordant isolates of determination of EMB resistance were 91 strains in two methods and the concordance rate was 89.2%. There were 11 disconcordant isolates and the discrepancy rate was 10.8%. In the 11 strains of discrepant isolates between two methods, 7 strains (63.6%) were in accord with the results of MIC method (5 of 7 strains were EMB susceptible by PhaB but EMB resistant by the absolute concentration methods, 2 of 7 strains were EMB resistant by PhaB but EMB susceptible by the absolute concentration method). Conclusions The PhaB assay can be used for detection of EMB resistance in isolates of Mycobacterium tuberculosis easily and quickly within three days.This method do not need special instrument and may be used for rapid screening of M.tuberculosis with resistance to EMB.