Association of toxic capsule and cell wall mucopeptide with virulence in Gaffkya tetragena

[Biological activity of bacterial peptidoglycan (mucopeptide) (author's transl)]

A brief survey on the ultrastructure, the chemical composition and the immunological properties of bacterial cell wall peptidoglycan (mucopeptide) is presented. This paper deals with the various recently discovered biological activities of peptidoglycan. These could be divided into three different groups, namely: 1. Endotoxin-like properties: pyrogenicity, induction of the local Shwartzman reaction, increase in non-specific resistance to bacterial infection, release of 5-hydroxytryptamine from rabbit platelets, complement activation,gelation of amebocyte lysate. 2. Inflammatory reactions of skin and internal organs, aggressin activity (virulence factor), inhibition of phagocytosis of bacteria by granulocytes and macrophages, inhibition of growth of cell cultures, cytotoxity to granulocytes and macrophages. 3. Potentiation of humoral and cellular immune responses (adjuvant), enhancement of tumor defense in experimental animals. The potential mechanisms of action of peptidoglycan are discussed and attention is focused on the implications of the various peptidoglycan activities for medicine.

Immunobiological activity of cell wall antigens of Staphylococcus aureus

Guinea pigs sensitized with washed, Formalin-killed cells of Staphylococcus aureus, strains 263 or Copenhagen, were skin-tested with various antigens from these strains including washed viable and heat-killed whole cells, cell walls, the peptidoglycan complexes of the walls, teichoic acid, teichoic acid-peptidoglycan fragments, and peptidoglycan fragments. In nonsensitized control animals, all antigens but teichoic acid elicited acute inflammatory reactions which decreased in size after 10 hr. In animals sensitized with the Copenhagen strain, the reactions to all antigens but teichoic acid and peptidoglycan fragments from either strain remained erythematous and indurated for at least 30 hr and were interpreted as hypersensitivity of the delayed type. Responses in animals sensitized with strain 263 generally resembled those in controls, although in some experiments there was evidence of hypersensitivity.