Fowl cholera immunization in turkeys. II. Use of experimental epornitic method to study vaccine efficacy in flocks of turkeys.
Groups of turkeys were challenged with Pasteurella multocida (P-1059) by the contact method. In this method, turkeys are artificially infected by the intramuscular injection of P. multocida organisms and are then introduced into the test group. The death patterns resulting from this contact method of challenge are either normally distributed or skewed to the right.
Fowl cholera immunization in turkeys. I. Efficacy of various cell fractions of Pasteurella multocida as vaccines.
Cell fractions of Pastuerella multocida (P-1059) were tested as vaccines against fowl cholera in turkeys. These fractions were culture filtrate, cell wall, and cytoplasm. A second culture filtrate preparation made from cells grown on blood-agar rather than the standard medium was also tested along with a "combination" preparation made by recombination of the cell fractions. Each preparation was tested in three vehicles: saline, alum (0.5%), and Freund Incomplete Adjuvant (50%). The turkeys vaccinated with these preparations were challenged by exposure to an experimental epornitic of fowl cholera. The combination fraction appeared to be the most promising vaccine when compared to the protective action of the commercial bacterin included in the test as a positive control.
A Study of the Hemorrhagic Septicemia Pasteurellae
Early investigators depended for the diagnosis of hemorrhagic septicemia entirely upon the lesions and the bipolar staining and pathogenicity of the organisms encountered as etiologic agents. It is evident, therefore, that in early references, organisms of widely divergent characteristics have been included in the Pasteurellae group. The first report of an organism of this group was by Rivolta in 1877 following his study of fowl cholera. This investigation was followed by several others, establishing a host of organisms as the causative agents of the various hemorrhagic septicemia diseases. Hueppe, in 1886 was the first to observe the close relationship of the various organisms of the group when he used the name Bacterium septicaemia-hemorrhagica for the etiologic agents of fowl cholera, cattle, rabbit, and swine septicemia. Kitt, however, in 1885 used the term Bacterium bipolare-multocidum to embrace the organisms causing the disease in cattle, swine, deer, horses, sheep, and goats. These two authors were the first exponents of the unicist school. The work of Lignieres, however, is probably the basis of the zoologic species classification of the Pasteurellae, even though he recognized the close cultural and biochemic similarities of the various group constituents. Lignieres' classification was based almost entirely on the isolation history of the various organisms. This classification has prevailed up to the present, although experimental evidence has pointed to its inadequacy as a method of subdividing the genus. Baumgarten (1911) was one of the first investigators to doubt the value of the zoologic classification, basing his objection on the