Hosseini Nave Hossein, Mansouri Shahla, Emaneini Mohammad, Moradi Mohammad
Department of Microbiology and Virology, School of Medicine, Kerman University of Medical Sciences, Kerman, Iran.
Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Microb Pathog. 2016 Mar;92:68-71. doi: 10.1016/j.micpath.2015.11.015. Epub 2015 Dec 2.
Shigella is one of the important causes of diarrhea worldwide. Shigella has several virulence factors contributing in colonization and invasion of epithelial cells and eventually death of host cells. The present study was performed in order to investigate the distribution of virulence factors genes in Shigella spp. isolated from patients with acute diarrhea in Kerman, Iran as well as the genetic relationship of these isolates. A total of 56 isolates including 31 S. flexneri, 18 S. sonnei and 7 S. boydii were evaluated by polymerase chain reaction (PCR) for the presence of 11 virulence genes (ipaH, ial, set1A, set1B, sen, virF, invE, sat, sigA, pic and sepA). Then, the clonal relationship of these strains was analyzed by multilocus variable-number tandem repeat analysis (MLVA) method. All isolates were positive for ipaH gene. The other genes include ial, invE and virF were found in 80.4%, 60.7% and 67.9% of the isolates, respectively. Both set1A and set1B were detected in 32.3% of S. flexneri isolates, whereas 66.1% of the isolates belonging to different serogroup carried sen gene. The sat gene was present in all S. flexneri isolates, but not in the S. sonnei and S. boydii isolates. The result showed, 30.4% of isolates were simultaneously positive and the rest of the isolates were negative for sepA and pic genes. The Shigella isolates were divided into 29 MLVA types. This study, for the first time, investigated distribution of 11 virulence genes in Shigella spp. Our results revealed heterogeneity of virulence genes in different Shigella serogroups. Furthermore, the strains belonging to the same species had little diversity.
志贺氏菌是全球腹泻的重要病因之一。志贺氏菌有多种毒力因子，有助于其在结肠上皮细胞中定植和侵袭，最终导致宿主细胞死亡。本研究旨在调查从伊朗克尔曼急性腹泻患者中分离出的志贺氏菌属中毒力因子基因的分布情况以及这些分离株之间的遗传关系。通过聚合酶链反应（PCR）对总共56株分离株进行评估，其中包括31株福氏志贺氏菌、18株宋内志贺氏菌和7株鲍氏志贺氏菌，检测11种毒力基因（ipaH、ial、set1A、set1B、sen、virF、invE、sat、sigA、pic和sepA）的存在情况。然后，采用多位点可变数目串联重复分析（MLVA）方法分析这些菌株的克隆关系。所有分离株的ipaH基因均呈阳性。其他基因ial、invE和virF分别在80.4%、60.7%和67.9%的分离株中被检测到。set1A和set1B在32.3%的福氏志贺氏菌分离株中均被检测到，而属于不同血清群的分离株中有66.1%携带sen基因。sat基因存在于所有福氏志贺氏菌分离株中，但在宋内志贺氏菌和鲍氏志贺氏菌分离株中未检测到。结果显示，30.4%的分离株sepA和pic基因同时呈阳性，其余分离株为阴性。志贺氏菌分离株被分为29种MLVA类型。本研究首次调查了志贺氏菌属中11种毒力基因的分布情况。我们的结果揭示了不同志贺氏血清群中毒力基因的异质性。此外，同一物种的菌株多样性较小。
