Bacteriophages From Spontaneous Mouse Tumors.

Abstract

Bacteriophages active for Eb. dysenteriae were isolated from 4 out of 8 spontaneous tumors of mice. These were tumors of epithelial origin, which histologically resembled adeno-carcinomata. In size they ranged from 1 to 2 cc. in diameter and, with one exception, were covered with intact skin. They were removed aseptically, finely ground in a mortar under sterile conditions and emulsified in about 10 cc. of physiological saline. The emulsions were immediately filtered through sterile filter paper and then through a candle. These filtrates were tested in the customary manner for lytic action against strains of Eb. dysenteriae. Eb. typhi, Es. coli and of S. aureus. Several serial passages sufficed to elicit the presence of a bacteriophage active for Eb. dysenteriae. By the tenth passage a few drops of the filtrate was sufficient to lead to complete lysis of an actively growing broth culture of the organism. Typical plaques were produced on solid media. No detectable lysis was produced in the presence of the other bacterial species named. One strain of S. aureus was, however, strongly agglutinated by the active filtrates. The agglutinating principle was, moreover, transmitted in series by means of filtrates of the successively agglutinated cultures. That this was not a natural property of the organism was indicated by the appearance of the control cultures. While this “transmissible agglutinin” presumably represented a weak bacteriophage for the organism, it is curious that no appreciable lysis could be detected in the broth cultures during the course of these serial passages. At the end of the 25th serial passage the picture was essentially the same as during the earlier passages.

With the exception of one tumor presenting surface ulcerations, from which a mixed bacterial flora was cultivated, cultures made from the freshly harvested tumor pulp failed to reveal the presence of bacteria in the tumor tissue.