Exotoxin production by Aeromonas spp. in foods

Abstract

A psychrotrophic toxin-producing strain of Aeromonas hydrophila grew well in a range of food slurries (scallop, prawn, fish, chicken liver pate, liverwurst, chicken luncheon slice and commercial baby food preparations) held at refrigeration temperatures. In most foods, excluding the baby food preparations, exotoxins were produced at levels comparable with production in bacteriological broth without apparent food spoilage (all but prawn and fish). Addition of ultra-heat treated (UHT) milk to toxin-containing broth culture supernatants markedly decreased or removed haemolytic and cytotoxic activities, explaining low levels of toxins found in milk in a previous study. Baby food preparations did not inactivate exotoxins under similar conditions suggesting production of toxins rather than their inactivation was inhibited in these foods.