Penicillinase, an enzyme that destroys penicillin in vivo as well as in vitro, was discovered in 1940. It is produced by bacterial cultures of various strains of staphylococci, Escherichia coli, and Bacillus cereus and is thought to hydrolyze penicillin to penicilloic acid, which is not antigenic. Becker,1 Minno and Davis,2 and Zimmerman3 have reported it as an effective treatment for patients who react unfavorably to penicillin, but local and febrile reactions to it have occurred.
Minno and Davis2 reported that most patients complained of local pain and tenderness at the site of injection; the area frequently remaining painful for 24 hours. Zimmerman3 observed transient soreness at the site of injection in one-third of the patients treated; about one-fifth had severe soreness. He therefore recommended that the injection be given intragluteally and deeply. In 5% there was an occasional, mild, febrile reaction which lasted a few