Action of Bacteriophage in Experimental Typhoid Peritonitis. ∗

Abstract

While engaged in certain other experimental work, we had the opportunity to observe the effect of Bacillus typhosus bacteriophage upon peritonitis produced in guinea pigs and white mice, by means of the intraperitoneal injection of Bacillus typhosus. In view of the apparent possibilities of bacteriophage therapy, it was thought that the observations herein noted in the experimental animals, should be recorded.

A race of bacteriophage virulent for Bacillus typhosus was used, which was isolated and kindly furnished us by Professor D'Herelle and which in his hands had been found potent or virulent for several heterologous strains of typhoid bacilli.

The same strain of Bacillus typhosus was used as is described by us in the accompanying article.

At no time were we able to prevent the occurrence of secondary cultures at the end of from 48 hours to 4 or 5 days. A test of the virulence of secondary cultures was made by employing the last tube in a series of 12 dilutions, in which recurrent growth had occurred after lysis had been apparently complete for 5 days. The contents of this tube, at that time, when inoculated intraperitoneally, killed a full grown guinea pig in the same number of hours as did the suspension of the living organisms, used as a control.

To obviate the confusion resulting from the employment of such a phage, all bacteriophage was filtered, tested for sterility and pathogenicity, before inoculation.

The animals used consisted of 36 guinea pigs, and as many white mice.

The first series of experiments were performed to ascertain whether or not the in vivo presence of typhosus bacteriophage might prevent the formation of peritonitis. Four guinea pigs were given, intraperitoneally, 2, 3, 4, and 5 cc, respectively, of a salt solution suspension of a young culture of Bacillus typhosus and simultaneously there was administered, by the same route, 5 cc. of Bacillus typhosus bacteriophage, potency of 10-9, in ordinary bouillon of pH 7.6.