The epidemiology of Neisseria gonorrhoeae isolates in Greenland 1979-1990: the emergence, spread and disappearance of non-PPNG strains carrying the conjugative 38.9 kb plasmid.

BACKGROUND

In 1990, Greenland was one of the few areas in the world in which endemic occurrence of PPNG had not been reported. However, between 1982 and 1988 an increase in the prevalence of strains with chromosomally mediated resistance to penicillin had been noticed. The standard treatment regimen was changed early in 1983.

OBJECTIVE

To determine the prevalence of the 38.9 kb plasmid in gonococcal strains isolated in Greenland 1979-1990.

DESIGN

Retrospective (1979-1984) and prospective (1985-1990) studies of antimicrobial susceptibility and plasmid profile of consecutive N. gonorrhoeae isolates from patients attending the STD clinic in Nuuk, Greenland; selected strains from 1982-1984 were subjected to serotyping and auxotyping.

RESULTS

Before 1982, N. gonorrhoeae strains harboring the 38.9 kb conjugative plasmid were rare; in 1982, a sudden increase in the prevalence of these strains was strongly associated with the emergence of streptomycin-resistant strains with high-level chromosomally mediated resistance to penicillin, 70% of which carried the 38.9 kb plasmid. Determination of antimicrobial susceptibility pattern, auxotype and serovar supported the assumption of an epidemic spread of a single clone. The predominance of this clone was transient, but the 38.9 kb plasmid spread to penicillin-susceptible as well as to other clones of penicillin-resistant strains.

CONCLUSION

The emergence of the 38.9 kb plasmid in 1982 was linked to a single clone of strains, but the subsequent spread of the plasmid was independent of the presence of other plasmids, and its disappearance was not associated with a change in standard treatment regimen.