A Bacteriological Study of Mouse Tumors

Abstract

There have been numerous descriptions of the finding of microorganisms in tumors of human, animal, and vegetable origin. A certain divergence exists in the types of bacteria which have been found, and in the interpretation of the significance of their presence. Many have sustained the idea of an etiological relationship between bacteria or microparasites and tumor proliferation. More often the organisms have been regarded as coincidental, or secondary to changes in the tumor or in its overlying surface, or as casual invaders, which, in the case of transplantable tumors, were most probably introduced during one or more of the operations of transplantation, and, as the case might be, were individual to one group of animals or propagated from one generation of tumors to another. As such they might be pathogenic for the animals or carried as harmless saprophytes possibly pathogenic for other species. The older literature has been amply reviewed by Lewin. Kauffmann, in a series of reports, has described his success in isolating from the Ehrlich mouse carcinoma various strains of a T-bacterium, which he believes to be related to the B. tumefaciens of Smith. This organism he discovered in 50 per cent of the tumors; 30 per cent of the tumors showed a banal flora, and 20 per cent were sterile. Kauffmann has studied the biological characteristics of the various T-bacteria with which he was able to produce growths, considered by him to be infectious granulomas, in sunflower and sugar-beet plants, but which in general were non-pathogenic for animals. Other studies have demonstrated that B. tumefaciens apparently has no etiological relationship to malignant growth in animals (Borghi and Luzzatto).