Enterococcus faecalis tropism for the kidneys in the urinary tract of C57BL/6J mice
Enterococcus faecalis tropism for the kidneys in the urinary tract of C57BL/6J mice
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DOI：
10.1128/iai.73.4.2461-2468.2005
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发表时间：
2005-04-01
影响因子：
3.1
通讯作者：
Hultgren, SJ
中科院分区：
文献类型：
--
作者：
Kau, AL;Martin, SM;Hultgren, SJ
粪肠球菌是一种革兰氏阳性菌，可引起各种医院感染，其中尿路感染是最常见的。由于许多大肠杆菌的耐药性，这些感染非常难以治疗。粪杆菌分离株。尽管它们的性质很麻烦，但对E.粪便导致泌尿道疾病。使用尿路感染的小鼠模型，我们已经证明粪肠球菌能够在小鼠肾脏中持续至少2周。相比之下，来自相同小鼠膀胱的细菌滴度不一致，并且往往远低于从肾脏回收的细菌滴度。在其他临床大肠杆菌中也观察到这种对肾脏的偏好。粪菌菌株膀胱和肾组织的组织学检查表明，E。粪便在肾脏中诱导炎症反应，但在膀胱中不诱导。这种炎症反应是TLR2独立的，并没有诱导炎症标志物通常与尿路致病性大肠杆菌。利用竞争试验，我们证明了肾盂肾炎临床分离株比实验室菌株具有生长优势。粪便在肾脏中，但不是在小鼠的膀胱中。这些结果表明，E. faecalis对小鼠泌尿道中的肾脏具有向性，并且该系统可用于研究涉及泌尿道感染发病机制的因素。
Enterococcus faecalis is a gram-positive bacterium that can cause a variety of nosocomial infections of which urinary tract infections are the most common. These infections can be exceptionally difficult to treat because of drug resistance of many E. faecalis isolates. Despite their troublesome nature, little is known about the host or bacterial factors necessary for E. faecalis to cause disease in the urinary tract. Using a mouse model of urinary tract infection, we have shown that E.faecalis is capable of persisting in the kidneys of mice for at least 2 weeks. In contrast, bacterial titers from the bladders of the same mice were inconsistent and tended to be much lower than those recovered from the kidney. This preference for the kidney over the bladder is also observed in other clinical E. faecalis strains. Histologic examination of bladder and kidney tissues demonstrated that E. faecalis induced an inflammatory response in the kidney but not in the bladder. This inflammatory response was TLR2 independent and did not induce inflammatory markers typically associated with uropathogenic Escherichia coli. Using a competition assay, we demonstrated that a pyelonephritis clinical isolate had a growth advantage over a laboratory strain of E. faecalis in the kidneys but not in the bladders of mice. Taken together, these results demonstrate that E. faecalis has tropism for the kidneys in the urinary tracts of mice and that this system can be used to study factors involved in the pathogenesis of urinary tract infections.