Recent advances in the study of the taxonomy, pathogenicity, and infectious syndromes associated with the genus Aeromonas

Abstract

Over the past decade, the emergence of Aeromonas species as bona fide human pathogens and their probable role as etiologic agents of bacterial gastroenteritis have resulted in an explosion of scientific interest in the genus. Major accomplishments occurring in this field during that interval include a more refined taxonomy, identification of new cell-associated factors (surface layers, pili), and the molecular analysis of selected extracellular gene products that may play a critical role in pathogenesis (hemolysins, enterotoxins). This review provides an updated overview of recent systematic, clinical, and pathophysiologic advances and defines key areas of medical and scientific interest in which major questions remain unanswered.

Distribution ofAeromonasphenospecies and genospecies among strains isolated from water, foods or from human clinical samples

“…Mesophilic aeromonads are also suspected of being human pathogens capable of causing infections ranging from septicaemia to gastroenteritis [10]. In studies on the aetiology of human diarrhoea in developed countries Aeromonas spp.…”

“…In studies on the aetiology of human diarrhoea in developed countries Aeromonas spp. have been isolated in 1-3 % of faecal samples collected from patients [10,11]. Drinking water and food are the suspected vehicles (1,6,12].…”

“…Recently, ten species have been identified phenotypically: A. hydrophila, A. caviae (A. punctata), A. media, A. eucrenophila, A. sobria, A. jandaei, A. veronii, A. schubertii, A. trota and A. allosaccharophila [10,13]. Genetic methods differentiate 13 genetic species (hybridization groups, HGs).…”

“…Phenotypically A. jandaei (HG 9) and A. trota (HG 13) resemble A. sobria. A. trota is ampicillin sensitive thus differing from other known aeromonads [10]. Identification of the three commonly accepted species (A. hydrophila, A. caviae, A. sobria) is usually made in a clinical laboratory.…”

“…In a few cases, A. media (HG 5), A. schubertii (HG 12) and A. trota (HG 13) have also been associated with diarrhoea [10].…”