ABSTRACT
Aeromonas species were first recognized as pathogens of cold-blooded animals. The ability of Aerom onas hydrophila and A sobria to cause human infection has not been fully confirmed, however, it is established that they are potential infectious agents (Wadstrom and Ljungh, 1991). The presence of Aeromonas in drinking water, fresh and saline waters, brackish water and sewage has been demonstrated on a global scale. Cytotoxic strains have been isolated from a wide range of seafoods, meats and poultry, as well as from seed sprouts, lettuce or salad greens, mixed raw vegetables, parsley and carrots (Table 3). However, outbreaks associated with this organism have not been reported. The pathogen can grow rapidly on raw vegetables and seed sprouts at refrigeration temperature (Wadstrom and Ljungh, 1991). Controlled or modified atmospheric storage does not significantly affect the growth of A hydrophila.
Campylobacter spp. and in particular, Campylobacter jejuni, are thought to be the most frequent bacterial cause of gastrointestinal disease in humans (Tauxe, 1992; Alios and Taylor, 1998). Animals and birds are the main hosts of human pathogenic Campylobacter (Doyle and Jones, 1992; Altekruse et al., 1994) although water is also a potential source for contamination with these organisms (Koenraad et al., 1997; Mason et al., 1999). There is also potential for cross-contamination of fresh produce with Campylobacter from meat and poultry during food preparation (Beuchat, 1995). Campylobacter infections are usually manifested as abdominal pain, profuse diarrhoea and malaise with durations of two to seven days. Bacteraemias are rare and the fatality rate in industrialized countries is about 0.05% (Anonymous, 1995, 1997 2000a). Campylobacter has been isolated from a variety of produce items sampled from farmer’s markets in Canada and from mushrooms sampled from retail markets in the United States (Doyle and Schoeni, 1986). While consumption of contaminated food of animal origin, particularly poultry, is largely responsible for infection, Campylobacter enteritis has also been associated with lettuce or salads (CDC, 1998) (Table 3). Studies reported by Castillo and Escartin (1994) indicate that C. jejuni can survive on sliced watermelon and papaya for sufficient time to be a risk to the consumer.
