Cytotoxic material released from Staphylococcus epidermidis. I. Effects on [3H]thymidine incorporation of human lymphocytes.
Incorporation of [3H]thymidine ([3H]TdR) into tonsil lymphocytes was inhibited by native Staphylococcus epidermidis while Staphylococcus aureus Cowan I caused stimulation. The inhibitory effect of S. epidermidis was abolished by formalin treatment but not by heat killing. A toxic agent was released from S. epidermidis on gentle water extraction without lysing the bacteria. The extract contained protein and other UV-absorbing material, but did not exhibit haemolytic, lysozyme, catalase or protease activity. The heat-resistant, formalin-sensitive inhibitor present in the aqueous extract of S. epidermidis inhibited [3H]TdR incorporation of lymphocytes in a dose-dependent manner and decreased the viability of lymphocytes.
D003603:Cytotoxins / Q000633:toxicity*; D006358:Hot Temperature; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects* / Q000378:metabolism; D013210:Staphylococcus / Q000472:pathogenicity*; D013936:Thymidine / Q000378:metabolism*; D014316:Tritium
D003603:Cytotoxins; D014316:Tritium; D013936:Thymidine