School of Biotechnology, Campus-11, KIIT University, Bhubaneswar, Orissa, India.
Infect Immun. 2012 Sep;80(9):3236-46. doi: 10.1128/IAI.00180-12. Epub 2012 Jul 2.
Salmonella enterica subsp. I serovar Enteritidis exhibits type III secretion system 2 (TTSS2)-dependent early colonization and inflammation kinetics faster than those of closely related S. enterica serovar Typhimurium. To investigate the accelerated TTSS-2-dependent pathogenic potential of S. Enteritidis, we focused on its genome. Results of a previously published comparative genomic study revealed the presence of mutually exclusive genes in both serovars. In this study, we investigated the roles of six S. Enteritidis-specific genes in vivo by using differential fluorescence induction (DFI) through putative gene-specific promoters. The promoter construct associated with the gene locus SEN1140 induced green fluorescent protein (GFP) expression in the gut lumen, lamina propria, mesenteric lymph nodes, and related systemic organs. To further investigate the potential role of SEN1140, we compared a SEN1140 deletion mutant with S. Typhimurium in a TTSS1-deficient background. Interestingly, the S. Enteritidis mutant lacking SEN1140 did not show the unique TTSS-2-dependent early colonization and inflammation kinetic phenotype of S. Typhimurium. Consistent with this result, complementation of SEN1140 restored the TTSS-2-dependent accelerated inflammatory potential of S. Enteritidis. This report presents a suitable screening strategy that uses a combination of DFI, fluorescence-activated cell sorting, quantitative PCR, and wild-type isogenic tagged-strain techniques to explore the unique roles of S. Enteritidis-specific genes in bacterial pathogenesis.
肠炎沙门氏菌亚种 I 血清型肠炎亚种表现出 III 型分泌系统 2(TTSS2)依赖性早期定植和炎症动力学比密切相关的肠炎沙门氏菌血清型 Typhimurium 更快。为了研究肠炎沙门氏菌加速的 TTSS-2 依赖性致病潜力,我们专注于其基因组。先前发表的比较基因组研究的结果表明,这两种血清型都存在相互排斥的基因。在这项研究中,我们通过使用推定基因特异性启动子的差异荧光诱导(DFI)在体内研究了六个肠炎沙门氏菌特异性基因的作用。与基因座 SEN1140 相关的启动子构建体在肠道腔、固有层、肠系膜淋巴结和相关的系统器官中诱导绿色荧光蛋白(GFP)表达。为了进一步研究 SEN1140 的潜在作用,我们在 TTSS1 缺陷背景下比较了 SEN1140 缺失突变体与肠炎沙门氏菌。有趣的是,缺乏 SEN1140 的肠炎沙门氏菌突变体没有表现出肠炎沙门氏菌独特的 TTSS-2 依赖性早期定植和炎症动力学表型。与该结果一致,SEN1140 的互补恢复了肠炎沙门氏菌 TTSS-2 依赖性加速的炎症潜力。本报告提出了一种合适的筛选策略,该策略使用 DFI、荧光激活细胞分选、定量 PCR 和野生型同源标记菌株技术的组合来探索肠炎沙门氏菌特异性基因在细菌发病机制中的独特作用。