Further observations on a bacteriolytic element found in tissues and secretions

Abstract

In a previous communication one of us* (A. F.) described an anti-bacterial substance (lysozyme) normally present in the tissues and secretions of the body. Further experiments have been done in connection with this substance, and some of the results obtained are here described. Development of Strains of Bacteria Resistant to Lysozyme . It was shown in the earlier communication that lysozyme existed in the tissues and secretions affecting many microbes, but that one type of coccus, which was called the Micrococcus lysodeikticus , was especially suitable for experimental purposes with this lytic substance as it was particularly susceptible to the lytic action, so that if a small quantity of lysozyme-containing material was embedded deep in the centre of an agar plate, and then the whole surface of the plate was thickly planted with this microbe, there was inhibition of growth of the coccus for a considerable area around the embedded tissue. It was found, however, that if these culture plates were kept for two or three weeks there developed in the zone of inhibition a few isolated colonies of a microbe which appeared to be identical with M. lysodeikticus . The appearance of such a plate is shown in fig. 1 (Plate 6).