Second-step reconcentration of environmental samples by ammonium sulfate flocculation of beef extract

Some enteric viruses are sensitive to the acid environment utilized during the concentration of viruses from water. The use of a neutral flocculant, neutralized ammonium sulfate at 50% saturation, permitted the recovery of 97% of the simian rotavirus SA-11, 87% of Coxsackievirus B-4, and 88% of poliovirus type 1. This method should permit a better recovery of enteric viruses from the environment.