Ahmed Shariq, Shukla Indu, Fatima Nazish, Varshney Sumit K, Shameem Mohammad
Department of Microbiology, Jawaharlal Nehru Medical College, Aligarh Muslim University, Aligarh, Uttar Pradesh, India.
Department of TB and Respiratory Diseases, Jawaharlal Nehru Medical College, Aligarh Muslim University, Aligarh, Uttar Pradesh, India.
Indian J Med Microbiol. 2017 Oct-Dec;35(4):568-574. doi: 10.4103/ijmm.IJMM_17_321.
Isoniazid (INH) and rifampicin (Rif) are the key first-line antituberculosis drugs, and resistance to these drugs i.e., multi-drug-resistant tuberculosis (MDR-TB), is likely to result in treatment failure and poor clinical outcomes. India has the highest burden of TB and MDR-TB in the world, disproportionately high even for India's population. The GenoType® MTBDRplus molecular method allows rapid detection of Rif and INH resistance.
The present study was done to compare the performance of line probe assay test (GenoType® MTBDRplus) with solid culture method for an early diagnosis of MDR-TB.
Totally 1503 sputum samples of MDR-TB suspects were subjected to fluorescent microscopy. Decontamination was done by N-acetyl-L-cysteine and sodium hydroxide method. Fluorescent microscopy-positive samples were subjected to GenoType® MTBDRplus (HAIN Lifescience) assay. Sixty-two random samples were compared with phenotypic drug susceptibility testing (DST) (1% proportion method) using solid culture method by Lowenstein-Jensen media.
The sensitivity, specificity, positive predictive value and negative predictive value for detection of resistance to Rif were 94.74%, 95.35%, 90% and 97.62% and to INH were 92.00%, 91.89%, 88.46% and 94.44%, respectively, in comparison with the phenotypic DST.
GenoType® MTBDRplus has good sensitivity and specificity in detecting MDR-TB cases with a significantly lesser turnaround time as compared to conventional DST method and simultaneous detection of Rif and INH resistance. This technique saves several weeks of time required for culture and DST.
异烟肼（INH）和利福平（Rif）是关键的一线抗结核药物，对这些药物的耐药性，即耐多药结核病（MDR-TB），可能导致治疗失败和不良临床结局。印度是全球结核病和耐多药结核病负担最高的国家，相对于印度人口而言负担过高。GenoType® MTBDRplus分子方法可快速检测利福平和异烟肼耐药性。
本研究旨在比较线性探针分析试验（GenoType® MTBDRplus）与固体培养法在早期诊断耐多药结核病方面的性能。
对1503份耐多药结核病疑似患者的痰标本进行荧光显微镜检查。采用N-乙酰-L-半胱氨酸和氢氧化钠法进行去污处理。荧光显微镜检查阳性的标本进行GenoType® MTBDRplus（海因生命科学公司）检测。62份随机标本与使用罗-琴培养基的固体培养法进行的表型药物敏感性试验（DST）（1%比例法）进行比较。
与表型DST相比，检测利福平耐药性的灵敏度、特异度、阳性预测值和阴性预测值分别为94.74%、95.35%、90%和97.62%，检测异烟肼耐药性的分别为92.00%、91.89%、88.46%和94.44%。
GenoType® MTBDRplus在检测耐多药结核病病例方面具有良好的灵敏度和特异度，与传统DST方法相比周转时间显著缩短，且能同时检测利福平和异烟肼耐药性。该技术节省了培养和DST所需的数周时间。
