Department of Microbiology, King George's Medical University, Lucknow, India.
Department of Microbiology, King George's Medical University, Lucknow, India.
Diagn Microbiol Infect Dis. 2024 Feb;108(2):116159. doi: 10.1016/j.diagmicrobio.2023.116159. Epub 2023 Dec 12.
This study was done to determine frequency of isoniazid (INH) and fluoroquinolones FQ resistance among rifampicin sensitive strains of Mycobacterium tuberculosis and to study their mutation patterns. Retrospective analysis was done for samples with M. tuberculosis detected by Cartridge based NAAT (CBNAAT). They were tested sequentially by first line (FL) and second line - line probe assay (SL-LPA) depending on their drug resistance pattern and following diagnostic algorithm. Total 9722 (74.1 %) of 13124 NAAT positive samples were sensitive for rifampicin. On FL-LPA, 833 (8.6 %) were resistant to INH and of which 110 (13.2 %) were also resistant to FQ by SL-LPA. Most common mutations observed for INH resistance were katG S315T1 mutation in 615 (97.3 %) strains, inhA C15T mutation in 174 (86.6 %) strains and for FQ resistance were gyrA D94G mutation in 46 (41.8 %) strains. Heteroresistance, inferred mutations, combination of mutations and unique mutations were also observed in all genes.
本研究旨在确定利福平敏感型结核分枝杆菌中异烟肼（INH）和氟喹诺酮类药物 FQ 耐药的频率，并研究其突变模式。对基于试剂盒的核酸扩增技术（CBNAAT）检测到的结核分枝杆菌样本进行回顾性分析。根据其耐药模式和以下诊断算法，依次进行一线（FL）和二线-线探针分析（SL-LPA）检测。在 13124 份 NAAT 阳性样本中，共有 9722 份（74.1%）对利福平敏感。在 FL-LPA 中，833 份（8.6%）对 INH 耐药，其中 110 份（13.2%）对 SL-LPA 中的 FQ 也耐药。INH 耐药最常见的突变是 katG S315T1 突变，在 615 株（97.3%）菌株中观察到；inhA C15T 突变在 174 株（86.6%）菌株中观察到；而 FQ 耐药的最常见突变是 gyrA D94G 突变，在 46 株（41.8%）菌株中观察到。在所有基因中还观察到异质性耐药、推断突变、突变组合和独特突变。
