Health Education and Promotion Department, Tabriz University of Medical Sciences, Tabriz, Iran.
Doctoral of biotechnology, Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
Clin Exp Immunol. 2021 Feb;203(2):281-285. doi: 10.1111/cei.13549. Epub 2020 Dec 1.
Several explanations have been suggested concerning the variety in bacille Calmette-Guerin (BCG) vaccine efficacy on strains of Mycobacterium tuberculosis (Mtb). This study aimed to compare the effect of BCG vaccination history in the prevention of the occurrence of Mtb-Beijing and non-Beijing strains. In this cross-sectional study, 64 patients with pulmonary tuberculosis (TB) were recruited from the Iranian border provinces (North West and West). Isolates were subjected to restriction fragment length polymorphism (RFLP) analysis, using the insertion sequence IS6110 as a probe (IS6110 RFLP) and drug susceptibility testing using the proportion method. Samples were analyzed with Gel Compare II 6.6 and spss version 18. The mean age [standard deviation (SD)] of the patients was 54·4 (SD = 17·0). Overall, 49 cases (76·56%) had no BCG vaccination scar. The prevalence of Beijing strains was 9·38% and drug resistance proportion among the isolates was 14·1% (nine cases). There was a significant relationship between Beijing strains and tuberculosis (TB)-drug resistance in isolates (χ = 26·29, P < 0·001). There was also a strong association between vaccination history and Beijing strains (χ = 13·23, P = 0·002). Also, a statistical relationship was observed between Beijing strains and drug-resistant TB among patients with a history of vaccination (χ = 7·47, P = 0·002). This association was not maintained in the unvaccinated group (P = 0·102). These findings confirm the claim that the vaccine has different effects on different subspecies of tuberculosis. The cause of the high probability of drug resistance in patients with Beijing-TB and vaccination history requires further investigation with a higher sample size.
针对卡介苗（BCG）疫苗对结核分枝杆菌（Mtb）菌株的功效差异，已经提出了几种解释。本研究旨在比较 BCG 疫苗接种史在预防出现结核分枝杆菌-北京株和非北京株中的作用。在这项横断面研究中，从伊朗边境省份（西北和西部）招募了 64 例肺结核（TB）患者。使用插入序列 IS6110 作为探针（IS6110 RFLP）对分离株进行限制性片段长度多态性（RFLP）分析，并使用比例法进行药物敏感性测试。使用 Gel Compare II 6.6 和 spss 版本 18 对样品进行分析。患者的平均年龄[标准差（SD）]为 54.4（SD=17.0）。总体而言，49 例（76.56%）没有 BCG 疫苗接种疤痕。北京株的流行率为 9.38%，分离株的耐药比例为 14.1%（9 例）。北京株与分离株中的结核（TB）-耐药之间存在显著关系（χ²=26.29，P<0.001）。疫苗接种史与北京株之间也存在很强的关联（χ²=13.23，P=0.002）。此外，在有接种史的患者中，还观察到北京株与耐药性肺结核之间存在统计学关系（χ²=7.47，P=0.002）。在未接种组中，这种关联并不存在（P=0.102）。这些发现证实了疫苗对不同亚种的结核病有不同效果的说法。北京-TB 和接种史患者中高概率耐药的原因需要进一步研究，样本量更大。
