Trachoma Viruses Isolated in United States. ∗ 1. Growth in Embryonated Eggs

Abstract

Summary

From 6 active trachoma cases in the United States strains of“trachoma virus”have been isolated. Conjunctival scrapings suspended in broth-saline containing 1-10 μg/ml streptomycin were inoculated into yolk sac of embryonated eggs. From 1 to 6 blind passages were required for establishment of strains which subsequently reached titers of 10^6.3-10^7.4 egg LD₅₀/ml. The essential nature of ill-defined egg“quality”for isolation of“trachoma viruses”is discussed. The isolated agents produced unequivocal eye infections in M. Cynomolgus and in a human volunteer.