Dickerson H W, Clark T G, Leff A A
Department of Medical Microbiology, College of Veterinary Medicine, University of Georgia, Athens 30602.
J Eukaryot Microbiol. 1993 Nov-Dec;40(6):816-20. doi: 10.1111/j.1550-7408.1993.tb04480.x.
Efforts have been made to determine whether surface antigens could be used as biochemical markers to define strain differences in the parasitic ciliate Ichthyophthirius multifiliis. In previous studies, a wild-type isolate designated G1 was found to have surface proteins analogous to the immobilization antigens of Paramecium and Tetrahymena; rabbit antiserum against this strain immobilizes homologous cells in vitro. It has now been shown for two additional Ichthyophthirius isolates (designated G1.1 and G2) that immobilization antigens are both present and serologically distinct. Proteins of similar size, which cross-react in Western blots with rabbit antisera against immobilization antigens of the G1 strain, are nevertheless found in the G1.1 and G2 isolates. As shown by Southern blotting analysis, the G1.1 and G2 strains also contain genomic DNA sequences which hybridize with an immobilization antigen cDNA from G1 when probed under conditions of reduced stringency. The serotypic differences in immobilization between I. multifiliis isolates appear to be stable over time and provide a means of discriminating strains. In addition to providing a basis for comparative studies, the work described here has implications for the development of vaccines against this important fish parasite.
人们已努力确定表面抗原是否可用作生化标记，以界定寄生纤毛虫多子小瓜虫的菌株差异。在先前的研究中，发现一种名为G1的野生型分离株具有类似于草履虫和四膜虫固定抗原的表面蛋白；针对该菌株的兔抗血清可在体外使同源细胞固定。现已证明，另外两种多子小瓜虫分离株（命名为G1.1和G2）既存在固定抗原，且在血清学上有所不同。尽管在G1.1和G2分离株中发现了大小相似的蛋白质，它们在蛋白质印迹中与针对G1菌株固定抗原的兔抗血清发生交叉反应。如Southern印迹分析所示，当在低严谨条件下进行探针杂交时，G1.1和G2菌株还含有与来自G1的固定抗原cDNA杂交的基因组DNA序列。多子小瓜虫分离株之间固定反应的血清型差异似乎随时间稳定，并提供了一种区分菌株的方法。除了为比较研究提供基础外，此处描述的工作对开发针对这种重要鱼类寄生虫的疫苗也有影响。
