The Protective Action of Dysentery Bacteriophage in Experimental Infections in Mice

Abstract

A review of the literature on the in vivo action of dysentery-phage does not enable one to formulate any definite conclusions as to its value (Morton and Engley, 1945). There are about twice as many favorable as unfavorable reports. However, the use of dysentery-phage in man has been made under such poorly planned or executed experiments as to invalidate the results. The logical sequence of events should have been the testing of dysentery-phage in experimental animals, after the discovery of its action in vitro, before trying it on humans. To our knowledge this was not done. We wished to know whether dysentery-phage had any action in vivo and whether it would be reasonable to expect any prophylactic or therapeutic action in man. We feel that the results of animal experiments to be reported answer both questions in the affirmative. The tests were first conducted in November, 1942, under conditions which required secrecy. They were subsequently repeated under conditions which warrant publication. During the studies we were further encouraged by the following reports: Rakieten and Rakieten (1943) demonstrated protective action of Flexner-phage in developing chick embryos. MacNeal, Blevins, and Pacis (1943) proved protective action of Sonne-phage, likewise, in developing chick embryos. Dubos, Straus, and Pierce (1943) showed protective action of Shiga-phage in mice. Our results (Morton and Engley, 1944) with Flexner-phage in mice substantiate the findings of the above workers and in addition point out some quantitative relationship of bacteriophage to microorganisms in viva. These relationships we feel are very important in understanding bacteriophagy in vivo and in attempting to project the results obtained in one species of experimental animal to other species of animals, including man. MATERIALS Bacteriophage. Dysentery-Y phage, originally obtained from Professor Mtil-ler, Hygien-Institute, Koln-Lindental, by Prof. Stuart Mudd in 1932 and used repeatedly by the senior author in the Department of Bacteriology since that time, was employed. It was always generated aga nst Flexner-Y, strain P107. This preparation has been observed to retain its activity over four and one-half years of storage in the dark at room temperature. Dysentery-XS45 phage was produced by adapting the dysentery-Y phage to the X-S45 strain by the present authors. The dilution factor was such that it was impossible for any of the original Y-phage to be present in the ifitrate used as XS45-phage.