The 13th Five-Year Plan Project of the National Science and Technology Major Special Project of
目的：了解结核分枝杆菌（Mycobacterium tuberculosis ，MTB）katG、inhA和AhpC 基因突变与异烟肼（isoniazid ，INH）耐药相关性。方法：回顾性分析我院结核科2019年1月-2021年12月住院肺结核患者MTB培养及耐药基因检测结果。结果：痰或灌洗液MTB培养及菌种鉴定为人型结核分枝杆菌1712例，INH表型药敏测定敏感1308例，耐药404例；同时663例标本还送检INH耐药基因检测（分子药敏），99例未检出，564例分子药敏阳性，其中敏感390例，突变174例，突变位点为katG315、 inhA启动子和AhpC启动子。以表型药敏作为金标准，分子药敏检出INH耐药敏感性92.4%（95%CI：88.5%-96.4%）特异性96.2%（95%CI：94.3%-98.1%），阳性预测值91.4%（95%CI：87.2%-95.5%）阴性预测值96.7%（95%CI：94.9%-98.4%），约登指数88.6%，准确率95%。172例表型耐药患者检出耐药基因突变159例，分别为katG315 突变126次，inhA启动子突变25次 和 AhpC启动子突变 15次，katG315突变的发生率显著高于 inhA 和ahpC启动子( X2= 123.9 和 151.8，P ＜ 0.001)。52例表型高度耐药( MIC≥10μg /ml)患者，检出katG315突变 41次，inhA启动子突变8次，ahpC启动子突变5次，katG315突变率显著高于 inhA和 ahpC启动子 ( X2 = 28.0 p ＜ 0.001) 。katG315联合inhA或ahpC启动子突变较katG315单独突变相比，高度耐药率显著提高( X2 = 4.951，P=0.045）。katG315在耐多药和准广泛耐药组中突变率显著高于耐异烟肼组（X2= 5.522，p=0.018；X2=8.422，P=0.007）。katG315联合inhA/ahpC启动子在准广泛耐药组突变率显著升高（X2=8.916，P=0.006）。结论：katG315是本地区INH耐药主要突变位点，与INH高度耐药密切相关。
Objective：To investigate the association between katG, inhA and AhpC gene mutations and isoniazid (INH) resistance of Mycobacterium tuberculosis (MTB) in this region.Methods：The results of pre-anti-tuberculosis Mycobacterium tuberculosis (MTB) culture and drug resistance gene detection in hospitalized tuberculosis patients from January 2019 to December 2021 in the Department of Tuberculosis of our hospital were retrospectively analyzed.Results：MTB culture in sputum or lavage fluid and strain identification were performed in 1712 cases of Mycobacterium humantype, 1308 cases were sensitive to INH phenotype and 404 cases were drug-resistant. At the same time, 663 samples were also tested for INH resistance gene (molecular drug sensitivity), 99 cases were not detected, 564 cases were positive for molecular drug sensitivity, among which 390 cases were sensitive and 174 cases were mutated, and the mutation sites were katG315, inhA promoter and AhpC promoter. With phenotypic drug sensitivity as the gold standard, molecular drug sensitivity detected INH drug resistance sensitivity of 92.4% (95%CI: 88.5%-96.4%) specificity of 96.2% (95%CI: 94.3%-98.1%), positive predictive value of 91.4% (95%CI: 87.2%-95.5%) negative predictive value was 96.7% (95%CI: 94.9%-98.4%), the index was 88.6%, and the accuracy was 95%. Among 172 phenotypic drug-resistant patients, 159 cases of drug-resistant gene mutations were detected, including 126 katG315 mutations, 25 inhA promoter mutations and 15 AhpC promoter mutations, respectively. The incidence of katG315 mutations was significantly higher than that of inhA and ahpC promoters (X2= 123.9 and 151.8, P < 0.001). Forty-one katG315 mutations, eight inhA promoter mutations and five ahpC promoter mutations were detected in 52 patients with high phenotype resistance (MIC≥10μg /ml). The katG315 mutation rate was significantly higher than that of inhA and ahpC promoter (X2 = 28.0 p < 0.001). The high drug resistance rate of katG315 combined with inhA or ahpC promoter mutation was significantly higher than katG315 alone mutation (X2 = 4.951, P=0.045). The mutation rate of katG315 in MDR and quasi-extensively resistant groups was significantly higher than that in isoniazid-resistant groups (X2= 5.522, p=0.018; X2=8.422, P=0.007). The mutation rate of katG315 combined with inhA/ahpC promoter was significantly increased in the quasi-extensively resistant group (X2=8.916, P=0.006). Conclusions：katG315 is the main mutation site of isoniazid resistance in this region, which is closely related to isoniazid resistance and the degree of resistance.