Incidence and virulence of Aeromonas species in feces of children with diarrhea.

Aeromonas spp. occurring in feces of children with diarrhea were studied. Forty-eight strains were isolated from 2,025 specimens during a one year period. Only 11 of 44 strains tested yielded virulence factors (cytotoxin, hemolysin and hemagglutinin). Six strains were identified as Aeromonas sobria and five as Aeromonas hydrophila. The other strains isolated were identified as Aeromonas caviae. The biochemical characteristics associated with virulence factors were a positive Voges-Proskauer reaction, production of gas from glucose, fermentation of mannose, and absence of beta-lactosidase. Beta-D-glucosidase and esculin hydrolysis were the main characteristics used to differentiate Aeromonas sobria from the other two species. The incidence of Aeromonas spp. with virulence factors in feces of children with diarrhea would seem to vary widely from one area to another.