Tyrothricin against Sulfonamide-resistant Strains

Demonstration of the fact that strains of pneumococci may become resistant to the antibacterial action of the sulfonamide drugs has emphasized one of the potential difficulties that may arise in the chemotherapy of pneumonia. Not only has the acquisition of drug-fastness been induced by laboratory procedures (1 to 3) but individual strains of pneumococci obtained from patients have exhibited the capacity to change within the body from susceptible to resistant states during the course of treatment (4 to 7). The findings recorded in this report were derived from observations on two patients who had pneumococcus pneumonia with bacteremia and who failed to respond to sulfadiazine but improved rapidly following serum therapy. Clinical and laboratory data are presented which indicate that the infections were caused by drug-resistant pneumococci. In addition, the patients' strains have been used for experimental studies with particular reference to problems relating to treatment. For this purpose, infected mice have been treated with penicillin and with tyrothricin, as well as with sulfadiazine, in order to compare the curative action of the three agents.