Abstract:

In previous reports (1-3), it has been shown that lysosomal enzymes derived from a variety of mammalian leukocyte populations degrade 14C-Iabeled Micrococcus lysodeikticus and Staphylococcus albus extensively. On the other hand, group A streptococci are very resistant to lysis by leukocyte lysates. It has also been shown that, unlike S. albus and M. lysodeikticus, streptococci which are resistant to lysis in vitro persist for long periods in granulomatous lesions in mouse and rabbit tissues (1, 2). Other reports (4, 5) have shown that bacteria coated with specific antibodies are degraded at a slower rate following phagocytosis, as compared with untreated bacteria. Cationic polyelectrolytes, such as polylysine and polyarginine, agglutinate a variety of bacteria (6), and cationic proteins derived from leukocytes as well as from calf thymus histone are bactericidal for a variety of microorganisms (7). The possibility was therefore investigated that, by analogy to antibodies, cationic proteins may coat bacterial cells and thus interfere with their degradation by leukocyte lysosomal enzymes.