Abstract
The macrolide-azilide susceptibility testing (agar dilution, disk diffusion, Etest) criteria for 105 Neisseria gonorrhoeae strains were evaluated. In addition, the potencies of azithromycin, clarithromycin, and erythromycin were studied. The most active macrolide-azilide agent was azithromycin (MIC at which 90% of the isolates are inhibited [MIC90], 0.5 microgram/ml) compared with clarithromycin (MIC90, 1.5 to 2 micrograms/ml) and erythromycin (MIC90, 2 to 4 micrograms/ml). The Etest (AB Biodisk, Solna, Sweden) was observed to produce MIC results very similar to those of the reference agar dilution test (GC agar base), with 100% of the results within 1 log2 dilution step of the reference MICs. The disk diffusion test zone diameters for all three drugs correlated at an acceptable level (r = -0.81 to -0.92) with the reference agar dilution MICs. Interpretive criteria for susceptibility were proposed for azithromycin at a MIC of < or = 2 micrograms/ml and a disk diffusion test zone of > or = 25 mm. No category for resistance was proposed because of the paucity of strains for which MICs were > 2 micrograms/ml. These tentative criteria should be further validated by correlations with clinical trial data for gonococcal strains (as they emerge) that have azithromycin MICs above the proposed susceptible category range.
Full Text
The Full Text of this article is available as a PDF (185.2 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Barry A. L., Jones R. N., Thornsberry C. In vitro activities of azithromycin (CP 62,993), clarithromycin (A-56268; TE-031), erythromycin, roxithromycin, and clindamycin. Antimicrob Agents Chemother. 1988 May;32(5):752–754. doi: 10.1128/aac.32.5.752. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fekete T. Antimicrobial susceptibility testing of Neisseria gonorrhoeae and implications for epidemiology and therapy. Clin Microbiol Rev. 1993 Jan;6(1):22–33. doi: 10.1128/cmr.6.1.22. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Handsfield H. H., Dalu Z. A., Martin D. H., Douglas J. M., Jr, McCarty J. M., Schlossberg D. Multicenter trial of single-dose azithromycin vs. ceftriaxone in the treatment of uncomplicated gonorrhea. Azithromycin Gonorrhea Study Group. Sex Transm Dis. 1994 Mar-Apr;21(2):107–111. doi: 10.1097/00007435-199403000-00010. [DOI] [PubMed] [Google Scholar]
- Hopkins S. Clinical toleration and safety of azithromycin. Am J Med. 1991 Sep 12;91(3A):40S–45S. doi: 10.1016/0002-9343(91)90401-i. [DOI] [PubMed] [Google Scholar]
- Hughes J. H., Biedenbach D. J., Erwin M. E., Jones R. N. E test as susceptibility test and epidemiologic tool for evaluation of Neisseria meningitidis isolates. J Clin Microbiol. 1993 Dec;31(12):3255–3259. doi: 10.1128/jcm.31.12.3255-3259.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lassus A. Comparative studies of azithromycin in skin and soft-tissue infections and sexually transmitted infections by Neisseria and Chlamydia species. J Antimicrob Chemother. 1990 Jan;25 (Suppl A):115–121. doi: 10.1093/jac/25.suppl_a.115. [DOI] [PubMed] [Google Scholar]
- Moran J. S., Levine W. C. Drugs of choice for the treatment of uncomplicated gonococcal infections. Clin Infect Dis. 1995 Apr;20 (Suppl 1):S47–S65. doi: 10.1093/clinids/20.supplement_1.s47. [DOI] [PubMed] [Google Scholar]
- Oriel J. D., Ridgway G. L., Goldmeier D., Felmingham D. Treatment of gonococcal urethritis in men with a rifampicin-erythromycin combination. Sex Transm Dis. 1982 Oct-Dec;9(4):208–211. doi: 10.1097/00007435-198210000-00011. [DOI] [PubMed] [Google Scholar]
- Steingrímsson O., Olafsson J. H., Thórarinsson H., Ryan R. W., Johnson R. B., Tilton R. C. Single dose azithromycin treatment of gonorrhea and infections caused by C. trachomatis and U. urealyticum in men. Sex Transm Dis. 1994 Jan-Feb;21(1):43–46. doi: 10.1097/00007435-199401000-00009. [DOI] [PubMed] [Google Scholar]
- Tanaka M., Kumazawa J., Matsumoto T., Kobayashi I. High prevalence of Neisseria gonorrhoeae strains with reduced susceptibility to fluoroquinolones in Japan. Genitourin Med. 1994 Apr;70(2):90–93. doi: 10.1136/sti.70.2.90. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Van Dyck E., Smet H., Piot P. Comparison of E test with agar dilution for antimicrobial susceptibility testing of Neisseria gonorrhoeae. J Clin Microbiol. 1994 Jun;32(6):1586–1588. doi: 10.1128/jcm.32.6.1586-1588.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Waugh M. A. Open study of the safety and efficacy of a single oral dose of azithromycin for the treatment of uncomplicated gonorrhoea in men and women. J Antimicrob Chemother. 1993 Jun;31 (Suppl E):193–198. doi: 10.1093/jac/31.suppl_e.193. [DOI] [PubMed] [Google Scholar]