THE PARA-TYPHOID B—SUIPESTIFER GROUP OF BACTERIA STUDIES IN DIFFERENTIATION

Abstract

Strains (60) of this group were studied as to fermentative reactions, agglutination, complement fixation and agglu-tinin absorption. The present collection of Bacterium anatum strains is divisible into 2 types: (1) identical with Bact. aertrycke, (2) apparently independent. Fermentation reactions of the group are somewhat variable. Bad. suipestifer can usually be distinguished from "B types" by its failure to ferment arabinose, trehalose, dulcitol and inositol. The action of Bact. paratyphosum B and Bad. aertrycke on the fermentable substances studied is identical. Cross agglutination in the para B-suipestifer group has been found very irregular. Complement fixation is apparently more specific than simple agglutination, but can not be relied on to differentiate types within this group. By agglutinin absorption it is possible to divide the group into several types. Bad. paratyphosum B, Bad. aertrycke, and Bad. suipestifer are the 3 main types. In addition there are several smaller types antigenically distinct: the Abortus equinus, Binns, Newport and Stanley types of Schutze; the independent Anatum type and the Chesterfield type. Type G of Schutze, para C of Heimann, and Bad. suipestifer of Uhlenhuth, which have been described as being distinct types, seem to be identical with Bact. suipestifer. Certain limitations of the absorption test are set forth. The uncorrellated results of a negative absorption test may not always be taken as evidence of antigenic independence. Agglutination absorption is in some instances strain-specific rather than type-specific.