单一致病菌岛和多致病岛缺失对尿路致病性大肠杆菌 536 株固有肠外毒力的影响。
Effects of single and multiple pathogenicity island deletions on uropathogenic Escherichia coli strain 536 intrinsic extra-intestinal virulence.
机构信息
INSERM U722, Université Paris 7 Denis Diderot, Site Xavier Bichat, 16, rue Henri Huchard, 75018 Paris, France.
出版信息
Int J Med Microbiol. 2010 Nov;300(7):435-9. doi: 10.1016/j.ijmm.2010.04.013. Epub 2010 May 26.
BACKGROUND
Escherichia coli strain 536 is a uropathogenic strain harboring 7 pathogenicity islands (PAIs). Whether or not these PAIs additively contribute to extra-intestinal virulence is unknown.
METHODS
We tested 7 single and several multiple-PAI deletion mutants in a mouse septicemia model by monitoring mouse survival.
RESULTS
E. coli 536 mutants in which PAIs II or III were deleted showed a significant decrease in virulence compared to the wild type (WT). All other single-PAI deletion mutants were as lethal to mice as was the WT. The mutant in which all seven PAIs were deleted showed milder virulence than the mutants in which PAI III or PAIs III and IV were deleted. The mutant in which PAIs II, III, IV, V, and VII were deleted tended to be less virulent than the mutant with deletion of PAI III only. All together, these results indicate a rough additive effect of PAIs in extra-intestinal virulence.
CONCLUSION
All PAIs of E. coli 536 do not play the same role in extra-intestinal virulence estimated in a mouse septicemia model and PAIs cooperate in an additive manner to achieve extra-intestinal virulence.
背景
大肠杆菌 536 株是一种尿路致病性菌株，携带 7 个致病性岛（PAIs）。这些 PAI 是否会相加地促进肠外毒力尚不清楚。
方法
我们通过监测小鼠的存活情况，在小鼠败血病模型中测试了 7 种单缺失突变体和几种多 PAI 缺失突变体。
结果
与野生型（WT）相比，缺失 PAI II 或 III 的大肠杆菌 536 突变体的毒力明显降低。所有其他单 PAI 缺失突变体与 WT 一样对小鼠具有致死性。缺失所有 7 个 PAI 的突变体的毒力比缺失 PAI III 或 PAI III 和 IV 的突变体温和。缺失 PAI II、III、IV、V 和 VII 的突变体比仅缺失 PAI III 的突变体的毒力弱。总的来说，这些结果表明 PAI 在肠外毒力中存在大致的相加效应。
结论
在小鼠败血病模型中估计的肠外毒力中，大肠杆菌 536 的所有 PAI 并不发挥相同的作用，PAI 以相加的方式合作以实现肠外毒力。
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