Observations on the growth of trachoma and inclusion blennorrhoea viruses in embryonate eggs

Abstract

When trachoma and inclusion blennorrhoea viruses were titrated in chick embryo yolk sacs and the average day of death was plotted against dose of virus inoculated, sigmoid curves were obtained. Although all strains tested had the same growth rate, a given dose of some killed embryos more quickly than others. Strains killing most rapidly had the fewest elementary bodies per LD 50 and were the only strains to form inclusions in HeLa cells. During passage in the chick embryo three strains changed in their behaviour, killing embryos faster and acquiring the ability to form inclusions in HeLa cells.We wish to thank our colleagues Miss D. M. Graham and Dr W. A. Blyth for allowing us to quote some of their observations and Dr L. H. Collier and Dr G. G. Meynell for their help and criticism.