Department of Microbiology, SRM Medical College Hospital and Research Centre, Kattangulathur, Chennai, 603203, Tamilnadu, India.
Department of Natural Products, NIPER- Kolkata, Bengal chemicals, Chunilal Bhawan, Kankurgachi, Kolkata, 700054, West Bengal, India.
Infect Disord Drug Targets. 2024;24(8):e140324227967. doi: 10.2174/0118715265274164240117104534.
The toxin-antitoxin system is a genetic element that is highly present in (MTB), the causative agent of tuberculosis. The toxin-antitoxin system comprises toxin protein and antitoxin protein or non-encoded RNA interacting with each other and inhibiting toxin activity. has more classes of TA loci than non-tubercle bacilli and other microbes, including chaperone system, and hypothetical proteins.
The study aims to demonstrate the genes encoded toxin-antitoxin system in strains from clinical samples.
The pulmonary and extra-pulmonary tuberculosis clinical samples were collected, and smear microscopy (Ziehl-Neelsen staining) was performed for the detection of high bacilli (3+) count, followed by nucleic acid amplification assay. Bacterial culture and growth assay, genomic DNA extraction, and polymerase chain reaction were also carried out.
The positive PTB and EPTB samples were determined by 3+ in microscopy smear and the total count of tubercle bacilli determined by NAAT assay was 8.0×100 in sputum and 1.3×10 CFU/ml in tissue abscess. Moreover, the genomic DNA was extracted from culture, and the amplification of Rv1044 and Rv1045 genes in 624 and 412 base pairs (between 600-700 and 400-500 in ladder), respectively, in the H37Rv and clinical samples was observed.
It has been found that Rv1044 and Rv1045 are hypothetical proteins with 624 and 882 base pairs belonging to the family of toxin-antitoxin loci. Moreover, the significant identification of TA-encoded loci genes may allow for the investigation of multidrugresistant and extensively drug-resistant tuberculosis.
毒素-抗毒素系统是一种遗传元件，在结核分枝杆菌（导致结核病的病原体）中高度存在。毒素-抗毒素系统由毒素蛋白和抗毒素蛋白或非编码 RNA 相互作用，抑制毒素活性。结核分枝杆菌比非结核分枝杆菌和其他微生物具有更多类别的 TA 基因座，包括伴侣系统和假设蛋白。
本研究旨在证明临床样本中结核分枝杆菌菌株编码的毒素-抗毒素系统基因。
收集肺和肺外结核临床样本，进行显微镜下的痰涂片检查（齐-尼染色），以检测高菌计数（3+），然后进行核酸扩增检测。还进行了细菌培养和生长试验、基因组 DNA 提取和聚合酶链反应。
显微镜下的 3+确定了阳性的 PTB 和 EPTB 样本，NAAT 检测确定痰中总结核杆菌计数为 8.0×100，组织脓肿中为 1.3×10 CFU/ml。此外，从培养物中提取基因组 DNA，并在 H37Rv 和临床样本中观察到分别为 624 和 412 个碱基对（在阶梯中分别为 600-700 和 400-500 之间）的 Rv1044 和 Rv1045 基因的扩增。
已经发现 Rv1044 和 Rv1045 是具有 624 和 882 个碱基对的假设蛋白，属于毒素-抗毒素基因座的 家族。此外，对 TA 编码基因座的显著鉴定可能允许对多药耐药和广泛耐药结核病进行研究。
