Lysostaphin: an enzymatic approach to staphylococcal disease. II. In vivo studies.

Lysostaphin is a potent enzymatic anti-staphylococcal agent that lyses the cell walls of staphylococci in vitro. Studies described in the preceding paper demonstrated that lysostaphin rapidly killed staphylococci, was unaffected by human serum, and maintained its activity after prolonged incubation at body temperature.' Unlike the penicillins, lysostaphin was active in vitro against very large populations of stationary phase staphylococci. Serious staphylococcal infections continue to pose major therapeutic problems despite the introduction of the penicillinase-resistant penicillins and cephalosporins. Mortality rates from staphylococcal bacteremia approach 30%o,' and may be higher in staphylococcal endocarditis, especially when prosthetic cardiac valves are infected. It is believed that the therapeutic failures often result from the relative impotence of currently available antimicrobials against staphylococci residing in high titers in abscess lesions. Thus the availability of a chemotherapeutic agent active against large numbers of staphylococci in such lesions might be of great importance. Lysostaphin was therefore further studied as a therapeutic agent in experimental staphylococcal infections. These studies show that lysostaphin is highly effective in the treatment of experimental staphylococcal disease.