Mirnejad Reza, Jazi Faramarz Masjedian, Mostafaei Shayan, Sedighi Mansour
Molecular Biology Research Center, Baqiyatallah University of Medical Sciences, Tehran, IR Iran.
Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, IR Iran.
Microb Pathog. 2017 Aug;109:8-14. doi: 10.1016/j.micpath.2017.05.019. Epub 2017 May 12.
Brucella is zoonotic pathogen that induces abortion and sterility in domestic mammals and chronic infections in humans called Malta fever. It is a facultative intracellular potential pathogen with high infectivity. The virulence of Brucella is dependent upon its potential virulence factors such as enzymes and cell envelope associated virulence genes. The aim of this study was to investigate the Brucella virulence factors among strains isolated from humans and animals in different parts of Iran. Seventy eight strains of Brucella species isolated from suspected human and animal cases from several provinces of Iran during 2015-2016 and identified by phenotypic and molecular methods. The multiplex-PCR (M-PCR) assay was performed in order to detect the ure, wbkA, omp19, mviN, manA and perA genes by using gene specific primers. Out of 78 isolates of Brucella spp., 57 (73%) and 21 (27%) isolates were detected as B. melitensis and B. abortus, respectively, by molecular method. The relative frequency of virulence genes ure, wbkA, omp19, mviN, manA and perA were 74.4%, 89.7%, 93.6%, 94.9%, 100% and 92.3%, respectively. Our results indicate that the most of Brucella strains isolated from this region possess high percent of virulence factor genes (ure, wbkA, omp19, mviN, manA and perA) in their genome. So, each step of infection can be mediated by a number of virulence factors and each strain may have a unique combination of these factors that affected the rate of bacterial pathogenesis.
布鲁氏菌是一种人畜共患病原体，可导致家畜流产和不育，并在人类中引发称为马耳他热的慢性感染。它是一种兼性细胞内潜在病原体，具有高传染性。布鲁氏菌的毒力取决于其潜在的毒力因子，如酶和与细胞包膜相关的毒力基因。本研究的目的是调查从伊朗不同地区的人和动物中分离出的布鲁氏菌菌株的毒力因子。2015年至2016年期间，从伊朗几个省份疑似人和动物病例中分离出78株布鲁氏菌属菌株，并通过表型和分子方法进行鉴定。采用基因特异性引物进行多重聚合酶链反应（M-PCR）检测ure、wbkA、omp19、mviN、manA和perA基因。通过分子方法，在78株布鲁氏菌属分离株中，分别检测到57株（73%）和21株（27%）为羊种布鲁氏菌和牛种布鲁氏菌。毒力基因ure、wbkA、omp19、mviN、manA和perA的相对频率分别为74.4%、89.7%、93.6%、94.9%、100%和92.3%。我们的结果表明，从该地区分离出的大多数布鲁氏菌菌株在其基因组中具有高比例的毒力因子基因（ure、wbkA、omp19、mviN、manA和perA）。因此，感染的每一步都可能由多种毒力因子介导，并且每个菌株可能具有这些因子的独特组合，从而影响细菌致病的速率。
