Chen Ming-hong, Lin Zhi-hui, Peng Xiao-wei, Pan Xiu-zhen
Institute of Gastroenterology, Fujian Provincial Hospital, Fuzhou 350001, China.
Zhonghua Yi Xue Za Zhi. 2008 Sep 23;88(36):2581-3.
To investigate the role of Luxs gene on the regulation of virulence factors in Salmonella typhimurium.
Luxs gene knock-out strain of Salmonella typhimurium of the line 14028S was constructed. Media with Luxs gene knock-out 14028S or wild type 14028S bacteria were added into the media of cultured human intestinal epithelial cells of the line Caco. The numbers of colony formation unit (cfu) were calculated so as to compare the invasion ability. Northern blotting was performed to examine the Luxs gene expression.
When the 14028S cells were in the early logarithmic phase the cfu number was 590, and in the middle and late logarithmic, and stationary phases, the cfu numbers were 246, 57, and 13 respectively. The Luxs gene expression levels increased gradually along with the bacterial growth into different phases. The cfu number A600 nm = 0.25 of the Luxs gene knock-out strain was 597, significantly higher than that of the wild type (315, P < 0.05).
Luxs gene may be a negative regulator on the invasion ability of Salmonella typhimurium.
研究Luxs基因在鼠伤寒沙门氏菌毒力因子调控中的作用。
构建鼠伤寒沙门氏菌14028S株的Luxs基因敲除菌株。将含有Luxs基因敲除的14028S或野生型14028S细菌的培养基加入到培养的Caco人肠上皮细胞培养基中。计算菌落形成单位（cfu）数量以比较侵袭能力。进行Northern印迹法检测Luxs基因表达。
14028S细胞处于对数早期时cfu数量为590，处于对数中期、后期及稳定期时，cfu数量分别为246、57和13。Luxs基因表达水平随着细菌生长进入不同阶段而逐渐升高。Luxs基因敲除菌株在A600 nm = 0.25时的cfu数量为597，显著高于野生型（315，P < 0.05）。
Luxs基因可能是鼠伤寒沙门氏菌侵袭能力的负调控因子。
