Monoclonal antibody and lectin probes recognize developmental and sporogonic stages of PKX, the causative agent of proliferative kidney disease in European and North American salmonid fish

Abstract

The lectin GS-I (Griffonia siniplicifol~a agglut~nin-I) and a recently developed monoclonal antibody (Mabl2) both recognized extrasporogonic (interstitial) and sporogonic (intraluminal) stages of the PKX myxosporean causing proliferative kidney disease (PKD) in salmonid fish. In histochemical and immunostains the lectin and antibody recognized PKX from North American and European salmonids including Atlantic salmon Salmo salar, chinook salmon Oncorliynchus tshawytscha, coho salmon Oncorhynchus kisutch, brown trout Salmo trutta, and grayling Thymallus thymallus. Although the specific structures recognized by the lectin and Mabl2 were not determined, double fluorescent staining techniques showed similar staining patterns with extrasporogonic or interstitial stages of the PKX myxosporean. An apparent inhibition between the lectin and Mabl2 in these double stains suggests that they recognize similar structures of the parasite. Sporogonic stages of PKX, some containing polar capsules, were detected with the lectin and Mabl2 stains in fish with typical extrasporogonic (interstitial) P M providing further confirmation of the relatedness of these stages. Both the lectin and 1Mabl2 provide useful tools for further study of the epidemiology of the PKX myxospo-rean, for future development of tests to detect anti-parasite antibodies in fish serum and for the identification of potential imrnunogens for vaccination of trout.