Occurrence of Vibrio, Salmonella and Staphylococcus aureus in retail fresh fish, mussel and shrimp

This study aimed to determine the presence of pathogenic Vibrio spp., S. aureus and Salmonella in 100 seafood samples purchased from retail outlets in Bursa city (Turkey). Of the samples examined including fish, mussel and shrimp, 67% were found to be contaminated with Vibrio. Presumed Vibrio spp. were identified by standard biochemical tests, and further confirmed by API 20E system. Identified Vibrio spp. were V. parahaemolyticus (28%), V. vulnificus (1%) and V. cholerae (1%), with the most prevalent being V. alginolyticus (37%). Six (6%) of the samples analysed were positive for S. aureus. However, no contamination of the samples with Salmonella was observed. Our results showed that seafood from retail outlets can be a likely vehicle for infections with Vibrio spp. and S. aureus. Seafood, pathogen bacteria, incidence, microbiological quality In addition to being a healthy food with nutritional value, seafood can also act as a source of foodborne pathogens (Hudecová et al. 2010; Bakr et al. 2011). Various outbreaks of bacterial disease associated with the consumption of seafood have been reported (Guerin et al. 2004; Friesema et al. 2012). From these seafood-borne bacteria, Vibrio spp. are Gram-negative rod-shaped and halophilic bacteria that generally widespread in the coastal and estuarine environments (Austin 2010). Among more than 20 Vibrio species known to be associated with human disease, V. cholerae, V. parahaemolyticus and V. vulnificus are the pathogenic species of Vibrio that pose the greatest threat to human health (Gopal et al. 2005; Cariani et al. 2012). Salmonella and S. aureus are the leading foodborne pathogens, causative agents of the most common enteric infections to humans (Lei et al. 2008; Kumar et al. 2009). These bacteria can enter the aquatic environment through wild animals, domestic stock, poor sanitation and inappropriate disposal of human and animal wastes (Amagliani et al. 2012). Various authors have reported the incidence of Salmonella (Woodring et al. 2012) and enterotoxigenic S. aureus (Popovic et al. 2010) in seafood. In this study, we investigated the prevalence of pathogenic Vibrio spp., Salmonella and S. aureus contamination in fish, mussel and shrimp from the retail level in order to assess health risks for consumers, and also determined the identification to species level of the Vibrio strains isolated from samples. Materials and Methods