Further Study on the Incidence of B. dysenteriae in the Normal Individual. ∗

Abstract

Study of the stools of 50 healthy individuals, selected from various sections of New Orleans, was previously reported. B. dysenteriæ was recovered from the feces in 6 instances, or 12%. Of these 6 isolations, 5 were the lactose fermenting strain described by Duval 1 , and one was the true Shiga type.

The present report completes the survey, which includes 50 additional cases. The first group was selected from the public clinics, the last group studied comprised cases selected from private practice. In the first group, the patients lived in various parts of the city, some under good, others under poor hygienic conditions; while those of the second group came from a less widely distributed area, and lived under much better hygienic conditions.

The same technique as previously used was employed. Fresh stool specimens were obtained by proctoscopic examinations, were cultured in dextrose bouillon for from 2 to 3 hours, plated, and B. dysenteriæ colonies subsequently searched for. The only variation from the previous technique was that the patients were given a mild laxative about 6 to 8 hours before the stool specimens were obtained, and in 3 instances, repeated examinations were made of the stool specimen.

From each of the normal cases, blood specimens were obtained for the purpose of testing for specific agglutinins. The organisms used in the agglutination test were B. Flexner, B. Duval, B. Shiga, B, Hiss Y. In those instances where B. dysenteriæ organisms were recovered, they were tested with the homologous serum and serum from the experimental immunized animal.

In 3 instances dysentery bacilli were isolated from the second group of 50 cases. This percentage is considerably less than in the first group selected from the public clinics. There is also a notable drop in percentage of the lactose fermenter, while B. Hiss Y., B. Flexner, were each encountered once.