An Unusually High Divalent Cation Requirement for Attachment of West Nile Virus to Primary Chick Embryo Cells

Abstract

Summary

An unusually high divalent cation requirement for maximal plaque count and maximal adsorption rate was found in the WNV-CE cell system. An increase in Mg²⁺ concentration from 1 − 10^-3 to 1 − 10^-1 M resulted in a 200-fold increase in average plaque count. When 1 − 10^-1 M Mg²⁺ was incorporated in the virus inoculum, WNV attachment was essentially complete in 50-60 min. If 1 − 10^-2 M or less Mg²⁺ was included in the adsorption diluent, maximal attachment was not complete within 300 min and only a fraction of the original virus content could be detected by plaque assay.