Fate of Skin Bacteria after Autogenous and Heterogenous Transplantation of Skin into Subcutaneous Tissue. ∗

Abstract

In comparing auto-, homoio- and heterotransplants of various tissues Loeb observed, in general, a greater number of polymorphonuclear leucocytes around or in the transplanted tissues in the last type of transplantation than in the 2 former. The question arose whether the appearance of these leucocytes was due to the presence of bacteria in heterotransplants or whether the leucocytes were attracted directly by the heterotoxins. These observations suggested the following investigations in which we wished to determine (1) what the fate is of bacteria normally present on the skin after transplantation into the subcutaneous tissue, (2) whether in different species the fate of the bacteria after subcutaneous transplantation differs, and (3) whether there is a difference in the fate of bacteria adherent to the skin in case of autogenous and heterogenous transplantation.

We transplanted pieces of ear skin of approximately the same size into pockets of the subcutaneous tissue. Before transplantation the hair of the skin to be used was clipped, but otherwise the skin was left unchanged. In different experiments the pieces were left in the subcutaneous pockets 1, 2 or 3 days before they were removed, with precautions which excluded bacterial contamination. We then determined the changes in the total number of bacteria in the transplants and the changes in the various types of bacteria found in the skin. As controls we made determinations of the bacterial flora of the normal ear skin of the animal that served as donor. The methods for the determination of the number of bacteria adherent to the surface of a certain area of skin, do not permit a quantitatively accurate counting of all the microorganisms present; but, inasmuch as the same methods were employed in all cases, approximate results are obtained which allow certain conclusions to be drawn. The animals used were guinea-pigs, rats and rabbits. In each species we studied autotransplants of skin. We also studied heterotransplants from guinea-pigs to rat, from rat to guinea-pig, from rabbit to guinea-pig and from guinea-pig to rabbit.