RAPD Analysis of Atypical Aeromonas salmonicida Isolated in Japan.

Abstract

The randomly amplified polymorphic DNA (RAPD) method of PCR amplification was used to analyze a group of non-motile aeromonads. Genomic DNA fingerprints were generated, using 12-mer random primers, for 29 strains of atypical Aeromonas salmonicida isolated from eight different species of fish in Japan and for references strains of A. salmonicida subsp. salmonicida, A. salmonicida subsp. achromogenes, A. salmonicida subsp. masoucida, and A. salmonicida subsp. smithia.All RAPD profiles, using primers A22 and A32, of atypical A. salmonicida strains were identical. The RAPD profile amplified by primer A31 was similar among isolates of the same species of fish. Some common fragments were found in atypical A. salmonicida strains amplified by primers A24 and A29. This indicates genomic homogeneity among atypical A. salmonicida strains isolated from the eight species of fish in Japan. However, RAPD patterns of the 4 reference strains differed from those of atypical A. salmonicida strains examined, suggesting genomic differences between atypical A. salmonicida and the others.