Biologic and Serologic Characteristics of Echo Viruses from West Virginia

Abstract

Summary The biologic and serologic characteristics of 30 echo viruses from Charleston, West Virginia, have been described. This group has been characterized as human enteric viruses which are not related to poliovirus, Coxsackie, herpes or adenovirus groups, which are not pathogenic for monkeys or newborn mice, but which produce cytopathic effects in tissue cultures of rhesus monkey kidney cells. Twenty of the 30 were typable as echo types 3, 6, 7, 8, 9, 11, 14, or a new type no. 15. A number of the remaining untypable viruses show cross neutralization reactions in one direction only, indicating the possibility of mixtures of viruses, antigenic deficiencies, or variations within a single type as already known to exist in the echo-6 virus group. The growth characteristics in monkey kidney, HeLa, and Maben cell tissue cultures have been described, and some strains have been shown to differ markedly in their ability to grow in these 3 cell types. Neutralization of these echo viruses by donor sera has been correlated with some of their growth characteristics in tissue culture. Those echo viruses which produced cytopathic effects rapidly and produced high virus titers in monkey kidney cell cultures were strongly neutralized. Those which produced cytopathic changes slowly and yielded only low virus titers were only weakly neutralized by sera from their human donors, as measured in tube cultures by the inhibition of the cytopathic response.