POSSIBLE VIRULENCE FACTORS OF AEROMONAS SPP. FROM FOOD AND WATER

Thirty-one isolates of Aeromonas spp. from food and water in Norway we re classified and tested for possible virulence factors including cyto toxins (tissue cultures, PCR), enterotoxins (PCR) and invasion ability (Caco-2 cells). Five different species were recorded, A. caviae (9/31 ), A. hydrophila (15/31), A. schubertii(3/31), A. trota (3/31) and A. veronii biovar veronii (1/31). One of the A. hydrophila strains was pr obably responsible for a small outbreak of food poisoning caused by in gestion of raw fermented fish. All the A. hydrophila strains produced and secreted cytotoxins at 37 degrees C, as well as two A. trota strai ns and the single A. veronii biovar veronii strain. In some cases incr eased cytotoxin secretion was observed under osmotic stress. The major ity of the A. caviae strains which produced cytotoxins at 30 degrees C were unable to produce and/or secrete cytotoxins at 37 degrees C. One A. schubertii strain and one A. caviae strain were invasive. (C) 1998 Federation of European Microbiological Societies. Published by Elsevi er Science B.V. All rights reserved.