COMPARISON OF 3 METHODS FOR THE CONCENTRATION OF POLIOVIRUS FROM MOROCCAN SHELLFISH

Three methods were evaluated for the concentration of poliovirus from artificially contaminated oysters (Crassostrea gigas), mussels (Mytilu s edulis) and carpet-shell clams (Ruditapes decussatus) grown in Moroc co. The methods tested were: an adsorption-elution-precipitation metho d, a beef extract elution acid-precipitation method, and a non-fat dry milk elution acid-precipitation method. For all shellfish species tes ted, the adsorption-elution-precipitation method yielded the lowest av erage virus recovery (27%), whereas the two elution-precipitation meth ods yielded average virus recoveries of 42% each. The beef extract elu tion acid-precipitation method yielded the highest virus recovery with clams (53%), whereas non-fat dry milk elution acid-precipitation was advantageous for mussels providing average virus recovery of 47%. For oysters, none of the tested methods gave satisfactory virus recovery. These results point towards the need for the development of better met hod(s) for the concentration of viruses from Moroccan oysters, while f or mussels and clams, the elution-acid precipitation methods may be sa tisfactory.