Molecular Epidemiology of Infections With Neisseria gonorrhoeae Among Visitors to a Sexually Transmitted Diseases Clinic

Abstract
To identify determinants for plasmid-mediated resistance to penicillin (penicillinase-producing Neisseria gonorrhoeae [PPNG]) and tetracycline (tetracycline-resistant N. gonorrhoeae [TRNG]) among gonococci, to determine the distribution of bacterial characteristics, and to correlate these with antibiograms and patient characteristics. Gonococcal isolates from 131 patients attending a sexually transmitted diseases clinic in The Netherlands in 1994 were auxotyped and serotyped and antimicrobial susceptibility was tested. Information on patient characteristics was collected at the initial visit. The most prevalent serotype, IB-1 (26%), proved to be related to sexual contact with casual partners, especially commercial sex partners. In addition, IB-1 strains were associated with PPNG and displayed higher minimum inhibitory concentrations (MICs) for ceftriaxone, cefuroxime, and ciprofloxacin. Homosexual men were more often infected with nonrequiring, IB-2, and IB-6 strains than heterosexuals. These strains were very sensitive to ceftriaxone and ciprofloxacin. Overall, one strain showed decreased susceptibility to ciprofloxacin (MIC 0.5 ug/ml), but no resistance to ceftriaxone, ciprofloxacin, or cefuroxime was observed. However, 31% of the isolates were TRNG, PPNG, or both. Determinants for these resistant strains among men were the use of antibiotics (odds ratio [OR] = 4.8, 90% confidence interval [CI] 1.3–19.1), Surinam or Morrocan origin (OR = 3.3, 90% CI 1.3–8.4), and homosexual contacts (OR = 0.1, 90% CI 0.03–0.4). Different types, with variable susceptibility, were associated with homosexual and commercial sexual behavior. PPNG and TRNG were more commonly isolated from antibiotic users, heterosexual individuals, and ethnic minorities. Continuous surveillance of susceptibility is needed to follow the spread of PPNG and TRNG and to detect resistance to the currently recommended agents in a timely fashion.