Importance of Aeromonas sobria in Aeromonas bacteremia.

Abstract

On the basis of DNA-DNA reassociation kinetics [1], core oligosaccharide analysis [2], and the electrophoretic mobility of selected cellular enzymes [3], recent taxonomic studies of motile spp. indicate that the group commonly referred to as the Aeromonas hydrophila complex is actually composed of nine or more distinct species, three of which are currently identifiable by using simple biochemical tests [4, 5]. Several studies have suggested that separating these groups may be of clinical as well as taxonomic interest because most enterotoxin-producing isolates are either A. hydrophila or sobria [6] and because differences in antimicrobial susceptibility between the three species have been noted [7, 8]. In addition to the above-mentioned properties, we have previously found [5] that ^90^0 of all blood isolates of submitted to our laboratory for biotyping belonged to either the A. sobria or A. hydrophila groups, with A. sobria predominating. Furthermore, studies conducted by Daily et al. [9] on the relative virulence of aeromonads in mice found A. sobria to be more pathogenic than A. hydrophila, although caviae was not separated from the latter group. We have subsequently confirmed the studies of Daily et al. [9] and have additionally demonstrated the relative avirulence of A. caviae [10]. To determine whether these biologic properties ascribed to each species in vitro correlate with manifestation of clinical disease, we have analyzed our recent experiences with bacteremia in our institution.