Abstract
The phenotypic properties and genotypic characteristics of 44 aeromonads isolated from fish affected by epizootic ulcerative syndrome (EUS) in Southeast Asia were investigated. Among the 13A. hydrophilaphenospecies 9 were genotypically identical toA. hydrophila (HG 1) and 4 wereA. veroniibiotypesobria (HG8Y) orA. veroniibiotypesobria-related genospecies. All the 6A. veronii biotype sobria phenospecies were placed in the same genospecies, A. veroniibiotypesobria. Of the 12A. jandaeiphenospecies, 5 wereA. veroniibiotypesobriaorA. veroniibiotypesobria-related genospecies and 7 wereA. jandaeigenospecies. Of 13Aeromonasisolates unspeciated by phenotyping 9 were genotypically identical toA. hydrophilaor very similar toA. hydrophilaand 2 isolates wereA. veroniibiotypesobriaor very similar toA. veroniibiotypesobria; 2 isolates could not be identified to genospecies level. These results strongly suggest thatAeromonasspecies from fish affected by EUS could not correctly be identified to the species level using various published biochemical schemes; it needs genetic identification like DNA-DNA hybridization.
