Radiosensibility of Vibrio cholerae O1 incorporated in oysters, to (CO)-C-60

Objective Evaluate the effect of ionizing irradiation by Co-60 On Vibrio ch olerae O1, El-Tor; Ogawa, non-toxigenic, incorporated in live oysters Crass ostrea brasiliana. Methods Samples of oysters were selected from Cananeia town in the South co ast of S. Paulo state, Brazil, contaminated with Vibrio cholerae and irradi ated with Co-60 at 0.5 and 1.0 kGy dosages. Results Showed significant reductions of the initial number of V. cholerae, ranging from 3.4 x 10(7) to 10(3) and 10(2) respectively. The D-10 values related with the respective doses of irradiation were 0.173 and 0.235. Conclusion Considering a 6 value as safety factor; it is concluded that 1.4 1 kGy irradiation dosage is necessary to eliminate a high number of V. chol erae viable cells in oysters. Controls were used in the experiment.