Comparison of Three Methods for the Concentration of Poliovirus from Moroccan Shellfish

Abstract

Three methods were evaluated for the concentration of poliovirus from artificially contaminated oysters (Crassostrea gigas), mussels (Mytilus edulis) and carpet-shell clams (Ruditapes decussatus) grown in Morocco. The methods tested were: an adsorption-elution-precipitation method, a beef extract elution acid-precipitation method, and a non-fat dry milk elution acid-precipitation method. For all shellfish species tested, the adsorption-elution-precipitation method yielded the lowest average virus recovery (27%), whereas the two elution-precipitation methods yielded average virus recoveries of 42% each. The beef extract elution 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 method(s) for the concentration of viruses from Moroccan oysters, while for mussels and clams, the elution-acid precipitation methods may be satisfactory.