Pasteurella Avisepticum ∗ Infection of Poultry.

Abstract

To extend our knowledge of epidemic diseases, we have undertaken a study of fowl cholera. Its microbic incitant, Pasteurella aviseptica, is similar to B. lepisepticum, the organism responsible for most of the snuffles and pneumonias of rabbits. 1 This latter disease being primarily an infection of the respiratory tract, suggested the possibility that Pasteurella aviseptica infects chickens by way of the air passages, leading to both the general manifestations commonly recognized as fowl cholera and the local involvements of the upper respiratory tract designated as “roup”, “colds”, etc. We have carried out experiments to test this theory, have made serial cultures of a nasal passage of White Leghorn fowls from 3 commercial flocks over a period of 6 months, and have carried out preliminary studies of the bacterial cultures obtained. This report summarizes the results.

A strain of Pasteurella aviseptica, obtained from Dr. Theobald Smith and designated Strain Pa, was administered intranasally to rabbits and mice. 0.01 cc. of an 18 hour rabbit's blood broth culture, dropped through the external nares over the nasal mucous membrane of rabbits, killed invariably within 24 hours. Septicaemia, petechial hemorrhages, and congestion of the lungs were found at autopsy.† Similar procedures usually killed mice; a few survived, however, and carried the virulent organism for more than 6 weeks.

In the natural host, a somewhat different response was anticipated. Groups of chicks, 4 to 5 weeks old, uniform in weight, with no previous exposure to the infection, raised from similar stock and under uniform conditions, were given one drop of culture by way of the nasal cleft. Some died of acute cholera, others survived as carriers; some developed specific blood agglutinins; others seemed entirely refractory. Adult fowls, treated similarly, showed still an additional type of reaction.