FIG. 1.

Digestion of HSV-1 with neuraminidases reduces infectious titer. (A) HSV-1 KOS produced in Vero cells was mock digested (□) or digested with the indicated neuraminidases (▪) for either 1 or 4 h, and the remaining infectious virus was determined by plaque assay in Vero cells. Mock-digested virus was also mixed with the indicated enzyme immediately prior to the plaque assay to minimize the time for digestion (▒). (B) HSV-1 KOS produced in Hep-2 cells was mock digested or digested with NEB 2-3 neuraminidase or V. cholerae neuraminidase for 4 h before the titers were determined in Hep-2 cells. Identical results were obtained with A. ureafaciens neuraminidase (data not shown). The data presented represent the means and standard deviations of three independent assays. All values are reported as percentages with the “mock” value defined as 100%. NEB 2-3, Salmonella enterica serovar Typhimurium LT2 neuraminidase; VC, V. cholerae neuraminidase.