Rapid identification of Aeromonas salmonicida subspecies salmonicida by the polymerase chain reaction

Randomly amplified polymorphic DNA (RAPD) products obtained from Aeromonas salmonicida subspecies salmonicida were cloned, and their specificity was assessed by DNA-DNA hybridization, The clone Asal-3 was specific to A, salmonicida subspecies salmonicida. The 680 base pair nucleotide sequence of Asal-3 was determined and used to synthesize a primer set for PCR, The species-specificity of this primer set was demonstrated by the presence of PCR products only from strains of A, salmonicida subspecies salmonicida, and not from A. salmonicida subspecies achromogenes, A, salmonicida subspecies masoucida, atypical A. salmonicida, A. hydrophila, A. caviae, A, sobria, Edwardsiella tarda, Enterococcus seriolicida, Pasteurella piscicida, Vibrio anguillarum and Yersinia ruckeri. Moreover, it was effective in detecting A. salmonicida subspecies salmonicida from the kidney of experimentally infected amago salmon (Onchorhynchus rhodurus subspecies macrostomus), The PCR products obtained demonstrated the potential of this primer set for the rapid diagnosis of furunculosis.