Diversity of isolates of penicillinase-producing Neisseria gonorrhoeae (PPNG) in Honolulu, Hawaii: 1982-1991

Abstract

Background and objectives: Gonococcal infections caused by penicillinase-producing Neisseria gonorrhoeae (PPNG) isolates have increased in geographic distribution and prevalence. It was postulated that PPNG strains would become endemic in Honolulu and that, in turn, this city would serve as a reservoir for the introduction of PPNG strains into the continental United States.

Goal of this study: To assess the role of Honolulu as a reservoir for PPNG strains by assessing the diversity and persistence of PPNG strains between 1982 and 1991.

Study design: A total of 432 PPNG strains were characterized by auxotype/serovar (A/S) class and plasmid content, and their distribution during the 10-year period was studied.

Results: Of 432 isolates, 373 (86.4%) possessed a 4.4-Mdal beta-lactamase plasmid; 39 (9.0%) possessed a 3.2-Mdal beta-lactamase plasmid; and 20 (4.6%) possessed a 3.05-Mdal beta-lactamase plasmid. A total of 53 A/S classes were identified. Asian, African, and Toronto PPNG strains belonged to 49 (92.5%), 15 (28.3%), and 11 (20.7%) A/S classes, respectively. Though all Toronto PPNG strains possessed a 24.5-Mdal conjugative plasmid, these plasmids could not be transferred by conjugation. Although some apparent microepidemics of PPNG strains were identified, most strains were isolated sporadically.

Conclusions: A large number of different strains have been associated with PPNG infections in Honolulu, but there was no evidence that any strain persisted endemically during the study period. These observations have important implications for the design and assessment of community gonorrhea control strategies.