Interaction of secreting pathogenic factors in vibriosis.

弧菌属细菌是自然水环境中的栖息者，包括一些致病菌，它们分泌多种致病因子。这些因素通常通过与其他因素合作或补充而引起症状。本课题通过研究创伤弧菌和拟态弧菌的溶血素、蛋白酶、铁载体或肠毒素等弧菌致病因子的协同作用和互补作用，了解弧菌病的一般机制。引起全身感染的弧菌（如创伤弧菌）的蛋白酶通过刺激血管通透性直接作为毒性因子发挥作用。而致病性弧菌（如拟态弧菌）的蛋白酶具有间接作用，通过修饰肠膜、部分消化肽段以切割某些特定部位来激活或灭活蛋白毒素，从而影响其定植机制。拟态弧菌溶血素的溶血作用不受弧菌蛋白酶部分消化的影响，但溶血素的肠毒活性因蛋白酶的水解而丧失。创伤弧菌溶血素也被弧菌蛋白酶部分消化，对生物型1和2溶血素活性的影响不同。这些结果为进一步了解弧菌的感染机制提供了有用的信息。

Bacteria of genus Vibrio are habitant of natural aquatic environment and include some pathogenic species which secret various pathogenic factors. These factors usually cause symptoms by cooperating with or complementing to other factors. This research project was carried out to understand general mechanism of vibriosis by studying cooperative and complementary action of pathogenic factors of vibrios, such as hemolysin, protease, siderphore or enterotoxin of Vibrio vulnificus and V.mimicus.Hemolysisn and proteases were extensively studied in this research. Proteases of vibrios causing systemic infection, such as V.vulnificus, act directly as the toxic factor by stimulating vascular permeability. However proteases of enteropathogenic vibrios, such as V.mimicus, show indirect action ; influencing the colonization mechanism by modifying intestinal membrane, activation or inactivation of protein toxins by partial digestion of the peptide for nicking some special part.Although hemolytic action of V.mimicus hemolysin was not influenced by partial digestion with protease produced by the vibrio, enterotoxic activity of the hemolysin was lost by the proteolysis. V.vulnificus hemolysin was also nicked by partial digestion of the vibrio protease, and the influenc to the activity was different between the hemolysins of biotype 1 and 2. These results are useful information for understanding mechanism of vibrio infection.