A GROUP OF PARATYPHOID BACILLI FROM ANIMALS CLOSELY RESEMBLING THOSE FOUND IN MAN

Abstract

1. In addition to the paratyphoid bacilli already named there exists a group which occurs in a variety of animals and which culturally is the same as Bacillus schottmülleri. As a rule this group can be separated from the latter by the type of clumps formed when bouillon cultures are used as antigens, while other antigens and complement fixation tests have failed to differentiate it. Agglutination absorption tests sharply separate the animal from the human paratyphoids. 2. No differences have been detected between organisms of this group derived from a number of animals and a common name for them is desirable, but for the present it seems better to call them calf-, swine-, mouse-, etc., typhus, according to the animal from which they were isolated. 3. Evidence exists in the literature that these organisms have been associated with food infections in man, particularly with what have been called paratyphoid B infections, but this function, as well as the part they play in animal diseases, is a subject for further study. 4. Well defined groups of paratyphoid such as Bacillus choleræ suis, the Voldagsen bacillus, Bacillus abortus equi, and Bacillus enteritidis are found in animals in addition to the organisms considered in this paper, and every attempt should be made to range newly isolated organisms in one or the other of these well recognized groups. 5. One of the objects in continuing this work was to find a method of differentiating these animal from the human paratyphoids less complicated than agglutination absorption. This object was not realized; the two groups are very similar and agglutination absorption seems to be the only means of classifying them.