The Recovery of Enteric Viruses and Coliphages from Shellfish

Shellfish meat was seeded with polio and reoviruses, the SA11 simian rotavirus and two coliphages, VI and MS2, in order to study methods of virus recovery. An adsorption-elution-flocculation procedure had an efficiency of recovery of about 66% for poliovirus, but only 3% for reovirus, 1% for SA11 virus and 2% for the two coliphages. The poor efficiency of recovery of all viruses except poliovirus, may be due to inactivation by exposure to low and high pH levels which form part of the recovery procedure. In another procedure seeded shellfish meat was simply homogenized in distilled water and centrifuged. The supernatant was decontaminated with chloroform and directly analyzed. The efficiency of recovery of this procedure was only about 8% for poliovirus, but 44% for MS2 and 50% for VI phages. Chloroform treatment had an adverse effect on the phages, because the elimination of this step increased the efficiency of recovery to 50% for MS2 and 62% for VI. These results indicate that the phages do not adsorb tightly to the shellfish meat and can, therefore, readily be recovered. Enteric viruses, on the other hand, adsorb tightly to shellfish meat and special procedures are required to accomplish meaningful recovery. These findings suggest that different procedures should be used for the recovery of various viruses from shellfish meat.