Verschuere L, Heang H, Criel G, Sorgeloos P, Verstraete W
Laboratory of Microbial Ecology and Technology, Department of Biochemical and Microbiological Technology, University of Ghent, B-9000 Ghent, Belgium.
Appl Environ Microbiol. 2000 Mar;66(3):1139-46. doi: 10.1128/AEM.66.3.1139-1146.2000.
In this study Vibrio proteolyticus CW8T2 has been identified as a virulent pathogen for Artemia spp. Its infection route has been visualized with transmission electron microscopy. The pathogen affected microvilli and gut epithelial cells, disrupted epithelial cell junctions, and reached the body cavity, where it devastated cells and tissues. In vivo antagonism tests showed that preemptive colonization of the culture water with nine selected bacterial strains protected Artemia juveniles against the pathogenic effects. Two categories of the selected strains could be distinguished: (i) strains providing total protection, as no mortality occurred 2 days after the experimental infection with V. proteolyticus CW8T2, with strain LVS8 as a representative, and (ii) strains providing partial protection, as significant but not total mortality was observed, with strain LVS2 as a representative. The growth of V. proteolyticus CW8T2 in the culture medium was slowed down in the presence of strains LVS2 and LVS8, but growth suppression was distinctly higher with LVS8 than with LVS2. It was striking that the strains that gave only partial protection against the pathogen in the in vivo antagonism test showed also a restricted capability to colonize the Artemia compared to the strains providing total protection. The in vivo antagonism tests and the filtrate experiments showed that probably no extracellular bacterial compounds were involved in the protective action but that the living cells were required to protect Artemia against V. proteolyticus CW8T2.
在本研究中，解蛋白弧菌CW8T2已被鉴定为卤虫属的一种致病病原体。其感染途径已通过透射电子显微镜观察到。该病原体影响微绒毛和肠道上皮细胞，破坏上皮细胞连接，并进入体腔，在那里破坏细胞和组织。体内拮抗试验表明，用九种选定的细菌菌株预先在养殖水中定殖可保护卤虫幼体免受致病影响。可区分出两类选定的菌株：（i）提供完全保护的菌株，在用解蛋白弧菌CW8T2进行实验性感染后2天没有死亡，以菌株LVS8为代表；（ii）提供部分保护的菌株，观察到显著但并非完全的死亡率，以菌株LVS2为代表。在菌株LVS2和LVS8存在的情况下，解蛋白弧菌CW8T2在培养基中的生长减缓，但LVS8对其生长的抑制明显高于LVS2。值得注意的是，与提供完全保护的菌株相比，在体内拮抗试验中仅对病原体提供部分保护的菌株在卤虫体内定殖的能力也受到限制。体内拮抗试验和滤液实验表明，保护性作用可能不涉及细胞外细菌化合物，而是需要活细胞来保护卤虫免受解蛋白弧菌CW8T2的侵害。
