Evaluation of cell lines and immunofluorescence and plaque assay procedures for quantifying reoviruses in sewage

Twelve continuous cell lines were tested to determine their sensitivity to reovirus types 1, 2, and 3 isolated from sewage. Madin-Darby bovine kidney (MDBK), rhesus monkey kidney (LLC-MK2), and human embryonic intestinal (intestinal 407) cells were most sensitive, respectively. In a similar study, MDBK cells were more sensitive than LLC-MK2 and Buffalo green monkey kidney (BGM) cells to sewage-isolated, protamine-precipitated reoviruses which had not been serotyped and had no previous cell contact. Sewage-isolated, protamine-precipitated reoviruses were also used in conjunction with MDBK cells in a comparative evaluation of immunofluorescent cell count and plaque assay procedures. The immunofluorescence assay is more sensitive and more rapid than the plaque assay. Reoviruses in excess of 10(4)/liter of raw sewage were detected by the immunofluorescent cell count assay.