[Penicillinase-producing strains of N. gonorrhoeae (PPNG) in the Zurich area, 1981-1988: incidence, antibiotic sensitivity and plasmid profile (3)].

During the period 1981 to 1988 2688 strains of N. gonorrhoeae from patients with gonorrhea were investigated at the Department of Dermatology. Zürich University Hospital. The frequency of gonorrhea decreased by 86% (from 566 in 1981 to 76 in 1988). The proportion of PPNG strains varied between 3.5% and 6.5% until 1986 and increased to 20% in 1988. If chromosomal penicillin resistant strains are included, in 1988 25% of all isolated N. gonorrhoeae strains were resistant to penicillin. Until 1984 West African and South East Asian countries were almost exclusively the source of the PPNG strains. In 1988 our PPNG strains were acquired in all five continents. Since 1985 roughly 20% of the PPNG infections have been acquired in Zurich. 95 out of 125 PPNG strains between 1981 and 1988 were examined for plasmids. 85 out of 95 PPNG strains contained the 4.4-MD plasmid ("Asia plasmid") and 8 out of 95 the 3.2-MD plasmid ("Africa plasmid"), while 63 out of 95 PPNG strains additionally contained the 24,6-MD transfer plasmid. Antibiotic resistance was as follows: all PPNG strains were resistant to penicillin (MIC greater than 1 microgram/ml). 80% to 100% were resistant to tetracycline (MIC greater than 1 microgram/ml), and 100% were sensitive to spectinomycin (MIC less than 30 micrograms/ml) and to thiamphenicol (MIC less than 2 micrograms/ml) respectively.