STUDIES ON PATHOGENIC FACTORS OF NON-HALOPHILIC PATHOGENIC VIBRIOS

一些种类的弧菌属栖息在淡水环境中，尽管几乎种类的弧菌属是嗜盐的。由这种非嗜盐弧菌引起的感染，包括霍乱弧菌（O1和非O1）或拟态弧菌，是由饮用淡水产品或饮用水引起的。我们对这类弧菌的生态学进行了研究，并从河流、池塘、湖泊和河口地区获得了许多分离菌。将分离株应用于家兔回肠环试验（RILT），部分菌株在试验中显示出致病性。据报道，致病性拟态弧菌菌株产生的肠毒素类似于霍乱毒素或产肠毒素大肠杆菌产生的毒素。然而，部分肠毒素阴性的拟态弧菌在RILT中表现出阳性反应。从一株拟弧菌中纯化出一种溶血素（VMH），并对其性质进行了研究。VMH与红细胞膜神经节苷脂结合形成约3nm的小孔，以胶体渗透方式溶血。半乳糖的存在对VMH分子的结合具有重要意义。通过RILT证实了VMH的肠毒性。拟态弧菌蛋白酶（VMP）是另一个致病因子。即VMP增强皮肤血管通透性，加速菌株粗滤液和凝集鸡红细胞的肠毒活性。此外，还证实了另一种血凝素（VMHA-2）的存在。VMHA-2能单独凝集家兔或小鼠红细胞，而凝集鸡红细胞则需要VMP的配合。VMHA-2作为殖民的作用正在调查中。采用gm1 -神经节苷酶联免疫吸附法，采用直接培养法对非o1型肠毒性霍乱弧菌进行了生态学研究，并研究了该弧菌与各种环境参数的相关性。从而获得了评价非嗜盐弧菌在食品卫生中的意义的各种重要信息。少

Some species of genus Vibrio inhabit in fresh water environments, although almost species of the genus are halophilic. Infections due to such non-halophilic vibrios including Vibrio cholerae(O1 and non-O1) or V. mimicus are caused by consumption of fresh water products or drinking water. We have studied ecology of such vibrios and obtained many isolates from river, pond, lake and estuary area. The isolates were applied to rabbit ileal loop test (RILT), and some of them showed pathogenicity in the test. It has been reported that pathogenic V. mimicus strains produce enterotoxins similar to cholera toxin or toxins produced by enterotoxigenic Escherichiacoli. However, some enterotoxin-negative V. mimicus strains showed positive reaction in RILT. A hemolysin (VMH) was purified from a V. mimicus strain and its property was studied. VMH bound to ganglioside of erythrocyte membrane and formed small pore sized ca. 3nm, and then hemolysis proceeded by colloid-osmotic manner. Existence of galact … More ose on reducing end of ganglioside molecule and a sialic acid on the galactose was important for the binding of VMH molecule. Enterotoxicity of VMH was demonstrated by RILT. V. mimicus protease (VMP) was shown to be another pathogenic factor. Namely, VMP enhanced skin vascular permeability, accelerated enterotoxic activity of the crude filtrate of the strain and agglutinated chicken erythrocytes. Furthermore, existence of another hemagglutinin (VMHA-2) was demonstrated. VMHA-2 agglutinated rabbit or mouse erythrocytes alone, but needed cooperation of VMP for agglutination of chicken erythrocyte. Role of VMHA-2 as a colonization is under investigation.Ecological study of enterotoxic V. cholerae non-O1 was carried out by direct culture method with GM1-ganglioside-enzyme linked immunosorbent assay and correlation of the vibrio with various environmental parameters were studied. Thus, various important informations to evaluate significance of non-halophilic vibrios in food sanitation were obtained. Less