"The aim of the present study was to investigate the effect of depuration on the safety of Mediterranean. mussels harvested in the Olbia gulf and to evaluate the efficacy of E. coli and Salmonella spp. as indicators. of the presence of naturally occurring Vibrios. Samples of mussels belonging to 10 batches of products,. from a Depuration Center, were collected before depuration (T0), after 4h (T4) and at the end (8 h, T8) of. depuration. Results showed an overall efficacy of the depuration in respect to the levels of E. coli counts. A. depuration for ~8 hours led to a rapid decline in the concentration, complying to the Food Safety Criteria of. the Reg. (EC) 2073\/2005. The decrease in numbers of E. coli does not correlate with the presence of naturally. occurring Vibrios, which decline is in even slower rate. The adoption of shorter treatment times for mussels. with high early counts of Vibrios could lead to a reduction unfi tted to guarantee the safety of consumers."