Clinical and environmental isolates of Aeromonas species (five A. hydr
ophila isolates, three A. caviae isolates, and two A. sobria isolates)
were tested for their adherence to HEp-2 cells. Clinical isolates of
A. hydrophila and A. sobria exhibited aggregative adherence similar to
that presented by enteroadherent-aggregative Escherichia coli. Bacter
ial aggregates adhered to cells with a typical ''stacked-brick'' appea
rance. In contrast, A. caviae strains showed a diffuse adherence patte
rn.