HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Liu, C. Articles by Bang, F. B. Search for Related Content PubMed PubMed Citation Articles by Liu, C. Articles by Bang, F. B.

An Analysis of the Difference Between a Destructive and a Vaccine Strain of NDV (Newcastle Disease Virus) in the Chick Embryo

Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland

Abstract

Three strains of NDV (CG179, B and vaccine), differing from each other in virulence for chickens and chicks, multiplied equally well in the allantoic sac of embryos and attained a maximum titer about 24 hours after allantoic inoculation. This was demonstrated both by repeated sampling of the same embryo and by titering pooled allantoic fluids from different eggs at different intervals. The results of the two methods were identical.

The virulent strain (CG179) multiplied rapidly in all tissues of the embryo and produced an early viremia and a fulminating infection. The embryos died in less than 48 hours.

In contrast, the vaccine strain gained entrance to the blood much later, and multiplied slowly in embryo tissues such as muscle, liver and brain. However the lungs of 16–17 day old embryos were particularly susceptible to this strain of virus. The severe pneumonia was accompanied by an accumulation of a large amount of virus in this tissue.

Footnotes

¹ Present address: Department of Bacteriology and Immunology, Harvard School of Medicine, Boston, Mass.