Swain P, Nayak S K
Aquatic Animal Health Division, Central Institute of Freshwater Aquaculture, Kausalyaganga, Bhubaneswar 751002, Orissa, India.
Fish Shellfish Immunol. 2003 Oct;15(4):333-40. doi: 10.1016/s1050-4648(02)00178-x.
Different serological tests viz. indirect ELISA, indirect blocking ELISA, competitive ELISA and serum agglutination tests were evaluated to detect antibodies against Edwardsiella tarda in naturally infected fish sera for seromonitoring and epizootiological studies. Approximately 66.6, 62.5, 57.6 and 16.6% of the field sera samples were found to be positive by indirect ELISA, competitive ELISA, indirect blocking ELISA and serum agglutination test, respectively. The percentage of serum samples positive for E. tarda antibodies in serum agglutination, competitive ELISA and indirect blocking ELISA, when compared with indirect ELISA, were 33.3, 83.6 and 66.6%, respectively, but its use was restricted due to the requirement of several conjugates against different fish species and the difficulty in assaying large numbers of serum samples from different fish species in a limited time to enable seromonitoring of the disease prevalence. No significant difference (P<0.05) in the mean optical density value was found in indirect and competitive ELISA. Although the competitive ELISA was slightly less sensitive than the indirect ELISA, it could accommodate a large number of serum samples with one anti-rabbit conjugate, and the need for different fish conjugates as required in indirect ELISA was eliminated. As in medical and veterinary practices, these tests can now be used in aquaculture practices for seromonitoring and study of pre-exposure of Indian major carps to pathogens in enzootic areas.
对不同的血清学检测方法，即间接酶联免疫吸附测定（ELISA）、间接阻断ELISA、竞争ELISA和血清凝集试验进行了评估，以检测自然感染鱼类血清中针对迟缓爱德华氏菌的抗体，用于血清监测和流行病学研究。通过间接ELISA、竞争ELISA、间接阻断ELISA和血清凝集试验，分别发现约66.6%、62.5%、57.6%和16.6%的现场血清样本呈阳性。与间接ELISA相比，血清凝集试验、竞争ELISA和间接阻断ELISA中针对迟缓爱德华氏菌抗体呈阳性的血清样本百分比分别为33.3%、83.6%和66.6%，但其应用受到限制，因为需要针对不同鱼类的几种结合物，且在有限时间内难以检测来自不同鱼类的大量血清样本以进行该疾病流行率的血清监测。间接ELISA和竞争ELISA在平均光密度值上未发现显著差异（P<0.05）。虽然竞争ELISA的敏感性略低于间接ELISA，但它可以用一种抗兔结合物检测大量血清样本，并且消除了间接ELISA中对不同鱼类结合物的需求。如同在医学和兽医实践中一样，这些检测方法现在可用于水产养殖实践中的血清监测以及印度主要鲤鱼在疫区对病原体的暴露前研究。
