The Relation of Antagonistic Coliform Organisms to Shigella Infections

Abstract

Summary A survey of individuals in a New York State Institution for the presence of fecal lactose-fermenting organisms antagonistic against a strain of Shigella paradysenteriae Flexner type III, revealed that 11.7 per cent of 2,648 strains were active in this respect, and that 30 per cent of 287 individuals harbored such organisms. A random sample of 30 highly antagonistic strains were shown to be capable of producing soluble antibiotic substances. Of the 287 individuals, 13 per cent were infected with either of two types of Shigella. The subjects who were infected with Shigella, had a significantly higher incidence of antagonist-bearers than the non-infected individuals. This tendency was especially marked in individuals whose cultures yielded only a small number of Shigella colonies. The feeble-minded group characterized by mongolism was found to have significantly more Shigella-positive cultures, and coliform antagonists, than the rest of the individuals. The Shigella prevalence in this group decreased with age, and with length of stay in the institution, but no relationship between these factors and antagonist-bearing was noted. The close similarity between the essential findings reported here, and the observations on a normal population in South Texas, is pointed out.