Blood Cultures, Blood Counts and Temperature Records in an Experimentally Produced “Air Sac Disease” and Uncomplicated Escherichia coli Infection of Chickens

Abstract

CERTAIN serotypes of Escherichia coli are capable of invading the respiratory system with subsequent invasion of the blood and pericardial sacs. The presence of certain respiratory disease agents in chickens make it possible to establish infection through aerosol exposure to E. coli, while the establishment of infection in birds that are free of these agents requires the inoculation of the organism directly into the air sac. The most important respiratory disease agents are the pathogenic Mycoplasma which are also called pleuropneumonia-like organisms (PPLO), infectious bronchitis virus (IBV) and Newcastle disease virus (NDV). MATERIALS AND METHODS The chickens used in these experiments were White Leghorns from PPLO free unvaccinated parents belonging to the Veterinary Science Department. They were raised in isolation rooms and were placed in modified Horsfall-Bauer units (Sieburth et al., 1961) 2 days before inoculation. The total leucocyte counts were made according to the method of Natt and Herrick …