Hemagglutination patterns of Aeromonas spp. in relation to biotype and source

Aeromonas spp. show patterns of hemagglutination with human group O cells in the presence of fucose, galactose, and mannose. These patterns are related to biotype as well as to the source of isolates. There was good correlation between hemagglutination pattern and the presence of diarrhea among strains isolated in Western Australia, which was the only source with adequate data for classification of children with an without diarrhea. Most of the environmental and other nonfecal isolates produced patterns different from those in strains associated with diarrhea. These results suggest that hemagglutinins should be considered with enterotoxins as virulence factors in Aeromonas spp.