A COMPARISON OF THE ANTIGENICITY OF THE EXTRACELLULAR PRODUCTS AND WHOLE-CELL SONICATES FROM MYCOBACTERIUM SPP. IN RABBITS, MICE AND FISH BY IMMUNOBLOTTING AND ENZYME-LINKED-IMMUNOSORBENT-ASSAY

The antigenicity of extracellular products (ECPs) derived from Mycobac terium spp. isolated from snakehead, Channa striata (Bloch), and Siame se fighting fish, Betta splendens (Regan), were examined by immunoblot ting and enzyme-linked immunosorbent assay (ELISA) using sera collecte d from immunized rabbits, mice and fish (rainbow trout). Ali three spe cies responded to a 65-kDa protein present in both the ECPs and whole cell sonicates (WCSs) from a variety of Mycobacterium spp. Crossreacti vity of anti-M. tuberculosis and anti-human heat-shock protein monoclo nal antibodies (MAbs), and the presence of fibronectin binding protein s secreted into ECPs of mycobacteria were also examined. The MAbs agai nst human 60-kDa heat-shock protein cross-reacted with the band at 65 kDa in the ECPs of TB1 (isolated from snakehead fish) and the type str ain M. marinum, while the anti-M. tuberculosis MAb F29-47 elicited a s trong reaction with a band at 21 kDa with most of the ECPs from mycoba cterial strains examined. The major fibronectin-binding proteins were located between 21 and 25 kDa. The 65-kDa protein from ECPs of Mycobac terium spp. proved strongly immunogenic to rabbits, mice and fish. Rab bit antiserum against the 65-kDa protein from strain TB267 reacted wit h many non-Mycobacterium WCSs, and therefore, the 65-kDa protein from Mycobacterium spp. is believed to be a common protein found in many fi sh bacterial pathogens.