Gonorrhoea caused by a mixture of penicillinase-positive and -negative gonococci: a case report

A 23-year-old unmarried man was infected with gonorrhoea from a prostitute in Fukuoka City and was treated with ampicillin which resulted in failure. By a rapid iodometric test it was found that the isolates before the treatment were penicillinase-negative. After the ampicillin treatment, however, the isolates turned to penicillinase-positive but were, in fact, a mixture of penicillinase-positive and penicillinase-negative gonococcal strains. Treatment by spectinomycin and doxycycline resulted in failure but the gonorrhoea was cured by ribostamycin.