Listeria monocytogenes bile salt hydrolase is a PrfA-regulated virulence factor involved in the intestinal and hepatic phases of listeriosis
Listeria monocytogenes bile salt hydrolase is a PrfA-regulated virulence factor involved in the intestinal and hepatic phases of listeriosis
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DOI：
10.1046/j.1365-2958.2002.03080.x
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发表时间：
2002-08-01
影响因子：
3.6
通讯作者：
Cossart, P
中科院分区：
文献类型：
--
作者：
Dussurget, O;Cabanes, D;Cossart, P
单核细胞增生李斯特菌是一种细菌病原体，可引起人类和动物严重的食源性感染。它可以感知和适应宿主内外各种恶劣的微环境。一旦被哺乳动物宿主摄入，细菌病原体到达肠腔，在那里它遇到胆盐，胆盐除了在消化中的作用外，还具有抗微生物活性。L.的比较单核细胞增生性李斯特菌和无害李斯特菌基因组的研究表明，单核细胞生成特异性推定基因编码胆盐水解酶（BSH）。在这里，我们表明，bsh基因编码的功能性细胞内酶在所有致病性李斯特菌物种。bsh基因受已知L.单核细胞毒力基因此外，BSH活性在低氧浓度下增加。bsh的缺失导致体外对胆汁的抵抗力降低，豚鼠经口感染后粪便携带细菌减少，小鼠静脉接种后毒力和肝脏定植减少。综上所述，这些结果表明BSH是一种新的PrfA调节的L。单核细胞增生毒力因子参与肠和肝阶段的绦虫病。
Listeria monocytogenes is a bacterial pathogen causing severe food-borne infections in humans and animals. It can sense and adapt to a variety of harsh microenvironments outside as well as inside the host. Once ingested by a mammalian host, the bacterial pathogen reaches the intestinal lumen, where it encounters bile salts which, in addition to their role in digestion, have antimicrobial activity. Comparison of the L. monocytogenes and Listeria innocua genomes has revealed the presence of an L. monocytogenes-specific putative gene encoding a bile salt hydrolase (BSH). Here, we show that the bsh gene encodes a functional intracellular enzyme in all pathogenic Listeria species. The bsh gene is positively regulated by PrfA, the transcriptional activator of known L. monocytogenes virulence genes. Moreover, BSH activity increases at low oxygen concentration. Deletion of bsh results in decreased resistance to bile in vitro, reduced bacterial faecal carriage after oral infection of the guinea-pigs, reduced virulence and liver colonization after intravenous inoculation of mice. Taken together, these results demonstrate that BSH is a novel PrfA-regulated L. monocytogenes virulence factor involved in the intestinal and hepatic phases of listeriosis.