Two genotypes of the intestinal parasite Ceratonova shasta infect Oncorhynchus mykiss: genotype 0 results in a chronic infection with low mortality while genotype IIR causes disease with high mortality. We determined parasite load and the relative expression of six immune factors (IgT, IgM, IL-6, IL-8, IL-10, IFNG) in fish infected with either genotype over 29 days post-exposure. In genotype IIR infections the host responded with upregulation of inflammatory and regulatory cytokines. In contrast, genotype 0 infection did not elicit an inflammatory response and expression of IFNG and IL-10 was lower. Antibody expression was upregulated in both infections but appeared to have limited efficacy in the virulent genotype IIR infections. Histologically, in genotype 0 infections the parasite migrated through the tissue layers causing inflammation but minimal damage to the mucosal epithelium, which contrasts with the severe pathology found in genotype IIR infections.

肠道寄生虫Ceratonova s​​hasta的两种基因型感染Oncorhynchus mykiss：基因型 0 导致慢性感染，死亡率低，而基因型 IIR 导致疾病高死亡率。我们确定了在暴露后 29 天内感染任一基因型的鱼中的寄生虫负荷和六种免疫因子（IgT、IgM、IL-6、IL-8、IL-10、IFNG）的相对表达。在基因型 IIR 感染中，宿主的反应是炎症和调节细胞因子的上调。相反，基因0型感染没有引起炎症反应，并且IFNG和IL-10的表达较低。抗体表达在两种感染中均上调，但在毒性基因型 IIR 感染中似乎效果有限。组织学上，在基因 0 型感染中，寄生虫通过组织层迁移，引起炎症，但对粘膜上皮细胞的损伤最小，