LECTIN HISTOCHEMICAL-STUDIES ON SPHAEROSPORA SP (MYXOSPOREA) FROM ITALIAN BROWN TROUT, SALMO-TRUTTA L

A Sphaerospora sp. (Myxosporea) infection (presumably S. truttae) was identified on a trout farm in northeastern Italy. Parasites were detec ted in kidneys from infected brown trout, Salmo trutta L., over a 2-ye ar period. Extrasporogonic, sporogonic stages and mature spores were s imultaneously detected in the same fish. Traditional diagnostic method s for Sphaerospora spp. rely on the detection of the myxosporean devel opmental stages in Giemsa-stained kidney smears or haematoxylin-eosin stained tissue sections. A histochemical method was employed where 10 biotinylated lectins (Con-A, DBA, SBA, GS-I, PHA-P, LEA, PWM, RCA(1), WGA and UEA-I) and the avidin-biotin-peroxidase complex (ABC) were use d on Sphaerospora-infected brown trout renal tissues and kidney imprin ts. Five monoclonal antibodies against PKX (Mab 12, MabA3, MabC5, MabD 4 and MabB4) were also tested. A lectin glycoconjugate binding pattern for Sphaerospora spp. is presented. This staining method shows that S BA lectin (Glycine max agglutinin) is a useful tool for the detection of the Sphaerospora spp. Only MabB4 bound some of the most mature spor ogonic stages. In contrast Mabs12, A3, C5 and D4, and GS-I lectin (Gri ffonia simplicifolia agglutinin) did not stain any of the Sphaerospora spp. stages, but did bind very specifically to the sporogonic and ext rasporogonic stages of PKX, the causative agent of proliferative kidne y disease (PKD).