OCCURRENCE OF POTENTIALLY PATHOGENIC VIBRIOS IN BIVALVE MOLLUSKS (MUSSELS AND CLAMS) FROM RETAIL OUTLETS IN THE NORTH OF SPAIN

Forty-three samples of shellfish (22 mussels and 21 clams) purchased f rom retail outlets from February through October were tested for the p resence of vibrios associated with human disease. Vibrio spp, was foun d in 51.26% of the samples. V. alginolyticus was the commonest Vibrio species found in the samples, followed by V. parahaemolyticus, V. fluv ialis and V. cholerae non-01. All V. parahaemolyticus isolated were Ka nagawa-phenomenon negative. Hemolytic activities were shown in all iso lates of V. fluvialis and V. cholerae. Bacterial indicators of quality and safety were within permitted limits by authorities. The results i ndicate the potential risks of food poisoning associated with the cons umption of raw or undercooked shellfish.