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首页> 外文期刊>Infection and immunity >Helicobacter pylori Pore-Forming Cytolysin Orthologue TlyA Possesses In Vitro Hemolytic Activity and Has a Role in Colonization of the Gastric Mucosa
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Helicobacter pylori Pore-Forming Cytolysin Orthologue TlyA Possesses In Vitro Hemolytic Activity and Has a Role in Colonization of the Gastric Mucosa

机译：幽门螺杆菌毛孔形成溶细胞素直向同源物TlyA具有体外溶血活性，并在胃粘膜定植中发挥作用

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Hemolysins have been found to possess a variety of functions in bacteria, including a role in virulence. Helicobacter pylori demonstrates hemolytic activity when cultured on unlysed blood agar plates which is increased under iron-limiting conditions. However, the role of an H. pylori hemolysin in virulence is unclear. Scrutiny of the H. pylori 26695 genome sequence suggests the presence of at least two distinct hemolysins, HP1086 and HP1490, in this strain. Previous studies have shown that the in vitro hemolytic activity of H. pylori is reduced when it is coincubated with dextran 5000, suggesting the presence of a pore-forming cytolysin. HP1086 has homology to pore-forming cytolysins (TlyA) from other bacterial species, and the introduction of the clonedH. pylori tlyA gene into a nonhemolyticEscherichia coli strain conferred hemolytic activity. AnH. pylori tlyA defined mutant showed reduced in vitro hemolytic activity, which appears to be due to pore formation, as the hemolytic activity of the wild-type strain is reduced to the same level as the tlyA mutant by the addition of dextran 5000. The mutant also showed reduced adhesion to human gastric adenocarcinoma cells and failed to colonize the gastric mucosa of mice. These data clearly suggest a role in virulence for H. pyloriTlyA, contrary to the suggestion that hemolytic activity is an in vitro phenomenon for this pathogen.
机译：已经发现溶血素在细菌中具有多种功能，包括对毒力的作用。 幽门螺杆菌在未溶解的血琼脂平板上培养时表现出溶血活性，在铁限制条件下会增加。但是， H的作用。幽门螺杆菌溶血素的毒性尚不清楚。对 H的审查。幽门螺杆菌26695基因组序列表明该菌株中至少存在两种​​不同的溶血素：HP1086和HP1490。先前的研究表明 H的体外溶血活性。当与葡聚糖5000共孵育时，幽门螺旋杆菌会减少，表明存在孔形成性溶细胞素。 HP1086与来自其他细菌物种的成孔细胞溶素（TlyA）具有同源性，并且与克隆的H导入相同。 pylori tlyA 基因导入非溶血性大肠杆菌菌株具有溶血活性。 An H。幽门螺杆菌tlyA 定义的突变体显示出降低的体外溶血活性，这似乎是由于孔形成所致，因为野生型菌株的溶血活性降低到与 tlyA 相同的水平通过添加右旋糖酐5000突变体。该突变体还显示出与人胃腺癌细胞的粘附性降低，并且未能在小鼠的胃粘膜上定植。这些数据清楚地表明 H在毒力中的作用。幽门螺杆菌TlyA，与溶血活性是该病原体的体外现象的暗示相反。

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