Comparative study of gonococcal susceptibility to penicillin in the United States, 1955-1969.

The incidence of gonorrhea continues to rise at an alarming rate. In 1969, the increase was about 13 96, and an estimated minimum of 1,680,000 cases of the disease will occur in the United States in 1970. Thus, gonorrhea continues to be the number one reported bacterial infection in adults. Although the Public Health Service recommends penicillin as the antibiotic of choice in the treatment of this disease, experts throughout the world generally agree that resistance of Neisseria gonorrhoeae to penicillin has developed and is continuing to develop. In 1954, 11 years after the advent of penicillin in the treatment of gonorrhea, in-vitro studies by Love and Finland [1] demonstrated that all of the 106 cultures of gonococci tested were inhibited by 0.06 units/ml or less of penicillin. Two years later, Thayer et al. [2] reported that 22 96 of the gonococcal isolates tested required 0.2 units/ml of penicillin for complete inhibition. Reyn [3] in 1963, after studying susceptibility of the gonococcus to antibiotics in Denmark, stated that 56 96 of the routine cultures were less sensitive to penicillin than those isolated in 1944.