Temporary Alteration of Character of an Organism Belonging to the Colon Group.

Abstract

In the spring of 1904 I was given the opportunity, through the kindness of my chief, Professor Adami, to study an organism isolated by him from the water of the St. Lawrence River. The results of these studies were published in the Journal 0} Medical Research,1 and several interesting points in regard to the interagglutination of the Coli-Typhoid group were noted. However, aside from the agglutination phenomenon, a peculiarity in the cultural characteristics was also observed. The microorganism on solid media resembled very much the appearance of colonies of B. coli. Grown on broth the microbe gave a stringy deposit, difficult to break up on shaking, and becoming more stringy on longer incubation. In litmus milk there was a primary acidity with a subsequent alkaline reaction of the medium, but no coagulation of the milk occurred. Indol was produced only after some weeks' incubation in Dunham's broth; and of the sugar broths, gas was produced most abundantly in the glucose medium. As was noted in my publication, the organism did not ferment lactose or saccharose when first isolated from the water, but did so after it had remained on the medium for some time. The saccharose broth was found to