Shenoy Vishnu Prasad, Kumar Ajay, Chawla Kiran
Department of Microbiology, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka, India.
Iran J Microbiol. 2018 Oct;10(5):275-280.
Despite high prevalence of MDR-TB in India very limited information about MDR-TB and mutation patterns in and genes among MDR-isolates of in south coastal Karnataka region is available; thus present study is an attempt to explore the extent of MDR-TB and mutation patterns prevalent among clinical isolates in this region using GenoType MTBDR assay.
A total of 256 sputum samples from Pulmonary TB patients suspected of MDR-TB were tested by GenoType MTBDR as per manufacturer's guidelines for detection of mutations conferring resistance to rifampicin and isoniazid. The results of GenoType MTBDR were recorded and analysed using SPSS version 22. For all analyses, a value <0.05 was considered statistically significant.
Fifty (19.53%) isolates were found MDR, 32 (12.50%) isolates were found mono-resistant to isoniazid and 15 (5.86%) isolates were found mono-resistant to rifampicin. Eleven isolates (4.3%) were found NTM. Mutation in codon S531L, S315T1 and C15T were most common in and genes respectively. Unknown mutations were found in 50.77% (33/65), 3.66% (3/82) and 26.83% (22/82) isolates for and genes respectively. Hetero-resistance in MDR, rifampicin monoresistant and isoniazid monoresistant isolates was found to be 26% (13/50), 20% (3/15) and 34.37% (11/32) respectively.
Mutation in codon S531L, S315T1 and C15T were most common mutations associated with MDR-TB. Further high number of isolates showed mutations in unknown regions and hetero-resistance thus more elaborate studies based on sequencing are desirable in this region.
尽管印度耐多药结核病（MDR-TB）的患病率很高，但关于卡纳塔克邦南部沿海地区MDR-TB以及MDR分离株中katG和rpoB基因的突变模式的信息非常有限；因此，本研究试图使用GenoType MTBDRplus检测法探索该地区临床分离株中MDR-TB的程度和普遍的突变模式。
按照制造商的指南，使用GenoType MTBDRplus对总共256份疑似MDR-TB的肺结核患者的痰标本进行检测，以检测赋予对利福平（RIF）和异烟肼（INH）耐药性的突变。使用SPSS 22版记录并分析GenoType MTBDRplus的结果。对于所有分析，P值<0.05被认为具有统计学意义。
发现50株（19.53%）分离株为MDR，32株（12.50%）分离株对异烟肼单耐药，15株（5.86%）分离株对利福平单耐药。11株（4.3%）分离株为非结核分枝杆菌（NTM）。密码子S531L、S315T1和C15T的突变分别在katG和rpoB基因中最为常见。分别在50.77%（33/65）、3.66%（3/82）和26.83%（22/82）的katG和rpoB基因分离株中发现未知突变。MDR、利福平单耐药和异烟肼单耐药分离株中的异质性耐药分别为26%（13/50）、20%（3/15）和34.37%（11/32）。
密码子S531L、S315T1和C15T的突变是与MDR-TB相关的最常见突变。此外，大量分离株在未知区域显示突变和异质性耐药，因此该地区需要基于测序进行更详细的研究。
