Frequency in the united states of non-β-lactamase-producing strains of neisseria gonorrhoeae possessing the 24.5-mdal conjugative plasmid

Joan S. Knapp, Jonathan Mark Zenilman, Roselyn J. Rice, Marilyn C. Roberts, Sarah A. Mclntire, Stephen A. Morse

Research output: Contribution to journalArticle


We characterized 475 non-β-lactamase-producing gonococcal isolates from five U. S. cities by auxotype, serovar, and plasmid content to determine the frequency of isolates with the 24.5-Mdal gonococcal conjugative plasmid. A total of 150 (32%) of all isolates possessed the 24.5-Mdal plasmid; these isolates represented between 10% and 53% of isolates from each city. Isolates possessing the 24.5-Mdal plasmid belonged to 45 (56%) of 81 auxotype/serovar (A/S) classes, or between 24% and 70% of the A/S classes isolated in each city. Overall, a higher proportion of strains isolated in the southern cities possessed the 24.5-Mdal plasmid than did those from northeastern or northwestern cities. These strains appear to have spread independently of the spread of β-lactamase-producing Neisseria gonorrhoeae strains. The prevalence of N. gonorrhoeae strains with the 24.5-Mdal conjugative plasmid has increased substantially and may have important implications for the epidemiology of gonorrhea caused by β-lactamase-pro- ducing strains.

Original languageEnglish (US)
Pages (from-to)79-83
Number of pages5
JournalSexually Transmitted Diseases
Issue number2
Publication statusPublished - 1989
Externally publishedYes


ASJC Scopus subject areas

  • Dermatology
  • Infectious Diseases
  • Microbiology (medical)
  • Public Health, Environmental and Occupational Health

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