Enterovirus recovery from laboratory-contaminated samples of shellfish

A sensitive and reproducible method for the recovery of enterovirus from the supernatant fluids of centrifuged homogenates of laboratory-contaminated shellfish meats is described. These fluids contain varying amounts of toxic materials that interfere with coxsackievirus B5 recovery in HEp-2 cells. Most of the cytotoxicity can be removed by precipitation with hydrochloric acid at a pH of 3.0–3.5. The acid-treated samples are diluted 1:4 in fetal bovine serum and then mixed with cell suspensions in plastic dishes to adsorb the virus particles which are subsequently enumerated as plaques. The method is applicable to oysters, mussels, and clams but especially the last two because of the high cytotoxic levels of these shellfish. Other methods of concentrating sample volumes are also examined as a means of detecting enteroviruses from naturally contaminated shellfish.