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Abstract：
Introduction Pulmonary tuberculosis (TB) remains a global health concern, exacerbated by the emergence of extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis. This study employs advanced molecular techniques, specifically polymerase chain reaction (PCR) profiling, to comprehensively characterize the genetic landscape of XDR pathogenic bacteria in patients diagnosed with pulmonary TB. The objective of the study is to elucidate the genes that are associated with drug resistance in pulmonary TB strains through the application of PCR and analyze specific genetic loci that contribute to the development of resistance against multiple drugs. Materials and methods A total of 116 clinical samples suspected of TB were collected from the tertiary healthcare setting of Saveetha Medical College and Hospitals for the identification of MTB, which includes sputum (n = 35), nasal swabs (n = 17), blood (n = 44), and bronchoalveolar lavage (BAL) (n = 20). The collected specimens were processed and subjected to DNA extraction. As per the protocol, reconstitution of the DNA pellet was carried out. The reconstituted DNA was stored at -20 °C for the PCR assay. From the obtained positive sample specimens, XDR pulmonary TB specimens were focused on the targeted genes, specifically the rpoB gene for rifampicin resistance, inhA, and katG gene for thepromoter region for isoniazid resistance. Results Out of a total of 116 samples obtained, 53 tested positive for pulmonary TB, indicative of a mycobacterial infection. Among these positive cases, 43 patients underwent treatment at a tertiary healthcare facility. Subsequently, a PCR assay was performed with the extracted DNA for the target genes rpoB, inhA, and katG. Specifically, 22 sputum samples exhibited gene expression for rpoB, inhA, and katG, while nine nasal swabs showed expression of the rpoB and inhA genes. Additionally, rpoB gene expression was detected in seven blood specimens, and both rpoB and inhA genes were expressed in five BAL samples. Conclusion The swift diagnosis and efficient treatment of XDR-TB can be facilitated by employing advanced and rapid molecular tests and oral medication regimens. Utilizing both newly developed and repurposed anti-TB drugs like pretomanid, bedaquiline, linezolid, and ethionamide. Adhering to these current recommendations holds promise for managing XDR-TB effectively. Nevertheless, it is significant to conduct well-designed clinical trials and studies to further evaluate the efficacy of new agents and shorter treatment regimens, thus ensuring continuous improvement in the management of this challenging condition.
摘要：
引言肺结核（TB）仍然是全球健康问题，结核分枝杆菌广泛耐药（XDR）菌株的出现加剧了这种情况。本研究采用先进的分子技术，特别是聚合酶链反应（PCR）分析，全面表征诊断为肺结核患者XDR病原菌的遗传格局。该研究的目的是通过应用PCR阐明与肺结核菌株耐药性相关的基因，并分析有助于对多种药物产生耐药性的特定遗传基因座。材料和方法从Saveetha医学院和医院的三级医疗机构收集了总共116例疑似结核病的临床样本，以鉴定MTB。其中包括痰（n=35），鼻拭子（n=17），血液（n=44），支气管肺泡灌洗（BAL）（n=20）。处理收集的样本并进行DNA提取。根据协议，进行DNA沉淀的重建。将重构的DNA储存在-20°C用于PCR测定。从获得的阳性样本样本中，XDR肺结核标本集中于靶向基因，特别是利福平抗性的rpoB基因，inhA,和katG基因为异烟肼抗性的启动子区。结果在总共获得的116个样本中，53例肺结核检测呈阳性,指示分枝杆菌感染。在这些积极的案例中，43名患者在三级医疗机构接受了治疗。随后，用提取的目标基因rpoB的DNA进行PCR测定，inhA,还有KatG.具体来说,22个痰样本显示rpoB基因表达，inhA,还有KatG,而9个鼻拭子显示rpoB和inhA基因的表达。此外,在7份血液标本中检测到rpoB基因表达,rpoB和inhA基因在五个BAL样品中均表达。结论采用先进和快速的分子检测和口服给药方案可以促进XDR-TB的快速诊断和有效治疗。利用新开发和重新利用的抗结核药物，如pretomanid，bedaquiline,利奈唑胺,和乙二甲酰胺.坚持这些建议有望有效管理广泛耐药结核病。然而，进行精心设计的临床试验和研究，以进一步评估新药和较短的治疗方案的疗效，从而确保持续改进这一具有挑战性的条件的管理。
