Genotypic Characterization of <i>katG</i>, <i>inhA</i>, and <i>ahpC</i> in Isoniazid-Resistant <i>Mycobacterium tuberculosis</i> Clinical Isolates in Shanghai, China

AuthorXingwei Caoen
AuthorQing Zhanen
AuthorYinjuan Guoen
AuthorJinghui Yangen
AuthorYin Liuen
AuthorBaoshan Wanen
AuthorXiaocui Wuen
AuthorQiaoshi Zhongen
AuthorYaping Hangen
AuthorYanhui Chenen
AuthorYanping Xiaoen
AuthorFangyou Yuen
AuthorLonghua Huen
Issued Date2020-01-15en
AbstractBackground: Mycobacterium tuberculosis is a pathogen that causes Tuberculosis and can invade various organs in infected patients. Its high morbidity and high mortality seriously threaten human health. In recent years, the continuous emergence of drug-resistant Tuberculosis bacteria has brought severe challenges to the prevention and control of Tuberculosis. Objectives: This study aimed to characterize the most frequent mutations of the katG, inhA, and ahpC genes in isoniazid (INH)-resistant M. tuberculosis clinical isolates in Shanghai Pulmonary Hospital, China, and investigate the relationship between gene mutations and the minimum inhibitory concentrations (MICs) of INH against M. tuberculosis. Methods: We collected 92 INH-resistant and 30 INH-susceptible clinical isolates of M. tuberculosis. The drug resistance profiles of M. tuberculosis clinical isolates against common anti-tuberculosis drugs were determined and sequencing analysis was performed. Results: Of 92 INH-resistant strains, mutations in the katG and inhA genes were observed in 64 (69.6%) isolates and five (5.4%) isolates, respectively, and only had one (1.1%) strain both katG and inhA mutations. Among them, 62 (67.4%) strains carried a single mutation at codon 315 of the katG gene and a new mutation site was found in the katG gene of two strains. We detected a single mutation site at codon 271 and three simultaneous mutation sites at codons 315, 431, and 439. Only one (3.3%) of the 30 isoniazid-sensitive strains had the katG mutation. The AhpC mutation was detected in no experimental strains. The KatG Ser 315 Thr (AGC315ACC) mutation occurred in 53 (68.8%) out of 77 strains with high MICs (≥ 1 g/mL) of isoniazid-resistant M. tuberculosis while five (33.3%) out of 15 strains with low MICs (less than 1 g/mL) had katG Ser 315 Thr (AGC315ACC) mutation. Conclusions: Isoniazid-resistant strains were dominated by Ser315 → Thr (AGC → ACC) substitution, which seems to be associated with multidrug resistance and high-level resistance to INH. Multisite mutations are related to multidrug-resistant M. tuberculosis and the discovery of new mutation sites provides a new basis for the detection of drug-resistant M. tuberculosis.en
DOIhttps://doi.org/10.5812/jjm.95713en
Keyword<i>Mycobacterium tuberculosis</i>en
KeywordINH-Resistanten
Keyword<i>katG</i>en
Keyword<i>inhA</i>en
Keyword<i>ahpC</i>en
KeywordMutationen
KeywordMICsen
PublisherBrieflandsen
TitleGenotypic Characterization of <i>katG</i>, <i>inhA</i>, and <i>ahpC</i> in Isoniazid-Resistant <i>Mycobacterium tuberculosis</i> Clinical Isolates in Shanghai, Chinaen
TypeResearch Articleen

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