The Effect of High Pressures on Bacteria

Abstract

During the past 8 or 10 years bacterial vaccines have been used extensively, but, on the whole, with very unsatisfactory results. Were it not for the excellent theoretical foundation on which vaccine therapy rests, its use would probably have been relegated to the past. Bacterial vaccines, as used today, judged by the practical results obtained, are of little or no value aside from typhoid vaccine as used prophylactically and the undisputed value of staphylococcic and B. acne vaccines, in certain types of cases. Protective immunization experiments with killed cultures on laboratory animals have likewise not been crowned with marked success. Facts such as these may readily be gleaned from a survey of the literature. The conclusion would therefore seem justified that the dead organisms do not offer a suitable antigen for immunization processes. During the past year while conducting some perfusion experiments on rabbits, we were much impressed by the rapidity with which bacteria were taken up by phagocytes. The particular experiment in question concerned the perfusion of the liver of rabbits with emulsions of staphylococci. By inserting cannulae in the portal vein and superior vena cava the liver could readily be perfused with Locke's fluid, containing large quantities of staphylococci in suspension. It was found that a fluid containing 9,000,000 organisms per cubic centimeter could be sterilized in a few minutes by being passed through this organ. The endothelial cells of the liver, on section, were found to be literally packed with bacteria following this operation. This observation suggested that vaccines injected into an individual for the purpose of