VIRULENCE FACTORS IN MOTILE AEROMONAS SPP ISOLATED FROM VEGETABLES

The pathogenicity of 48 strains of A. caviae and two of A. hydrophila isolated from vegetables (escarole, water-cress, lettuce) was evaluate d by adhesion and invasion tests as well as the production of enteroto xins in vivo (suckling mouse test) and in vitro (HEp-2 cells assay). A . hydrophila did not adhere or invade HEp-2 cells, probably due to the destruction of the cell monolayer by the cytotoxin that was detected in the ii? vitro test. Out of the A. caviae strains tested, 62.5% were classified as adhesive and only 2% from the total of strains were abl e to invade cells. In relation to enterotoxin production, 34% were pos itive in vivo and only 10% in vitro. All strains were negative in the suicidal phenomenon test which did not show any correlation with the p athogenicity of isolated strains. Based on the results obtained in thi s study we concluded that Aeromonas spp isolated from vegetables may r epresent risk to consumers' health.