Rapid genotype assay for detection of drug-resistant Mycobacterium tuberculosis

Abstract

Objective To explore the value of the genotype assays detection of the resistance of Mycobacterium tuberculosis to isoniazid and rifampin.Methods Seventy-eight clinical isolates susceptible of harboring Mycobacterium tuberculosis were subject to the mutation assay of katG gene S315T,inhA gene C-15Tand rpoB genes D516V,H526Y,H526D,S531L by using multiplex polymerase chain reaction-based linear probe membrane hybridization for analysis of isoniazid and rifampin resistance.These results were compared with the L-J solid medium culture,the gold standard,and MGIT BACTEC 960 drug sensitivity test.Results Genotype assay was associated with shorter time for the detection compared with routine drug sensitivity test (6 hours vs 3 months).The genotype assay yielded the sensitivity and specificity of 89％ (16/18) and 99％ (77/78) for isoniazid and 100％ and 100％ (13/13 and 78/78) for rifampin.Conclusion Genotype assay of Mycobacterium tuberculosis offers a rapid and accurate approach for the early diagnosis and treatment of drug-resistant tuberculosis,rendering it a promising technique to be extensively applied in clinical laboratories. Key words: Mycobacterium tuberculosis; Microbial sensitivity tests; Extensively drug-resistant tuberculosis ; Linear probe reverse membrane hybridization ; Genotype