The gyrB primers were found to produce an amplicon of the expected size for all A. salmonicida strains, for all the strains of A. bestiarum and A. piscicola and for the type strains of Aeromonas media, Aeromonas sobria, Aeromonas allosaccharophila, Aeromonas molluscorum, Aeromonas popoffii and Aeromonas fluvialis