Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Intermediate Reference Laboratory, Dharampur, Himachal Pradesh, India.
J Epidemiol Glob Health. 2018 Dec;8(3-4):220-224. doi: 10.2991/j.jegh.2018.02.100.
Rapid detection of drug resistance in is important for the successful treatment of tuberculosis. Fluoroquinolone and aminoglycoside resistance detection by molecular methods becomes more complex due to cross resistance among them. Thus, we aimed to determine cross-resistance and mutations in resistance genes for these drugs. A total of 336 multidrug-resistant tuberculosis (MDR-TB) cases received in Mycobacteriology laboratory were screened for phenotypic drug sensitivity testing for second-line drugs, i.e., ofloxacin, amikacin, kanamycin, and capreomycin. Molecular characterization of resistance was done by DNA sequencing of gene for fluoroquinolones (FQ), and multiplex allele-specific polymerase chain reaction (PCR) and PCR restriction fragment length polymorphism (RFLP) of gene for aminoglycosides. Of 336 MDR-TB isolates, 12 were extensively drug-resistant tuberculosis and 219 were sensitive to all the drugs tested. Ofloxacin, amikacin, kanamycin, and capreomycin resistance was detected in 101 (30.1%), 23 (6.8%), 27 (8.1%), and 19 (5.6%) cases, respectively. Eight different mutations were detected in gene in ofloxacin-resistant isolates and A1401G nucleotide change in gene were seen in 55.6% (15/27), 65.2% (15/23), and 68.4% (13/29) for kanamycin-, amikacin-, and capreomycin-resistant isolates, respectively. Information on second-line drug resistance-associated mutations could potentially be used for development of newer rapid diagnostic tests.
快速检测 耐药性对于结核病的成功治疗非常重要。由于氟喹诺酮类和氨基糖苷类药物之间存在交叉耐药性，因此分子方法检测这些药物的耐药性变得更加复杂。因此，我们旨在确定这些药物的交叉耐药性和耐药基因的突变。从分枝杆菌实验室共筛选了 336 例耐多药结核病（MDR-TB）病例，进行二线药物表型药物敏感性试验，即氧氟沙星、阿米卡星、卡那霉素和卷曲霉素。通过 DNA 测序对氟喹诺酮类（FQ）基因和多重等位基因特异性聚合酶链反应（PCR）和 PCR 限制性片段长度多态性（RFLP）对氨基糖苷类基因进行耐药基因的分子特征分析。在 336 例 MDR-TB 分离株中，12 例为广泛耐药结核病，219 例对所有测试药物敏感。在 101 例（30.1%）、23 例（6.8%）、27 例（8.1%）和 19 例（5.6%）病例中分别检测到氧氟沙星、阿米卡星、卡那霉素和卷曲霉素耐药。在氧氟沙星耐药分离株中检测到 8 种不同的基因突变，在 基因中观察到 A1401G 核苷酸变化，在卡那霉素、阿米卡星和卷曲霉素耐药分离株中分别为 65.2%（15/23）、68.4%（13/29）和 68.4%（13/29）。与二线药物耐药相关的突变信息可能有助于开发新的快速诊断测试。
