Tavanaee Sani Ashraf, Ashna Habib, Kaffash Afsaneh, Khaledi Azad, Ghazvini Kiarash
Infectious Diseases Department, Mashhad University of Medical Sciences, Mashhad, Iran.
Infectious Diseases Research Center, Kashan University of Medical Sciences, Kashan, IR Iran.
Ethiop J Health Sci. 2018 May;28(3):299-304. doi: 10.4314/ejhs.v28i3.7.
Drug resistance is a leading concern in control of TB. Resistance against rifampin as one of the most important drugs in the treatment of is caused by mutations in the 81-base pair region of the gene encoding the β-subunit of RNA polymerase. This study aimed to characterize the mutations in the rpoB gene associated with rifampin resistance among M. tuberculosis.
This study was conducted on referred samples of patients who did not respond to anti-TB treatment, in Tuberculosis Regional Reference Laboratory at Shariati Hospital. Drug susceptibility of M. tuberculosis isolates was surveyed using a proportional method on LJ medium. The isolates with resistant to rifampin were reconfirmed and then the rpoB gene was amplified and sequenced.
Among 27 resistant cases, 8, 11 and 8 people were from Iran, Afghanistan, and Turkmenistan, respectively. In 26 out of 27 isolates, rpoB gene mutations were observed. The most prevalent mutations belonged to the codon 53. Twenty-three isolates had just one mutation.
The use of rpoB gene sequencing led to the lack of the need for growth of the organism in the culture medium, the direct use of clinical samples, reduction of biological risks and a detection about 96.3% of MDR TB cases lowering the cost of the treatment.
耐药性是结核病控制中的一个主要问题。对利福平（治疗结核病最重要的药物之一）的耐药性是由编码RNA聚合酶β亚基的rpoB基因81个碱基对区域的突变引起的。本研究旨在鉴定结核分枝杆菌中与利福平耐药性相关的rpoB基因突变。
本研究在沙里亚蒂医院结核病区域参考实验室对接受抗结核治疗无反应患者的送检样本进行。采用比例法在LJ培养基上检测结核分枝杆菌分离株的药敏情况。对利福平耐药的分离株进行重新确认，然后扩增并测序rpoB基因。
在27例耐药病例中，分别有8例、11例和8例来自伊朗、阿富汗和土库曼斯坦。27株分离株中有26株观察到rpoB基因突变。最常见的突变属于密码子53。23株分离株仅有一个突变。
使用rpoB基因测序无需在培养基中培养细菌，可直接使用临床样本，降低生物风险，检测出约96.3%的耐多药结核病病例，降低了治疗成本。
