This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kam, K. M. Articles by Ho, N. K. Search for Related Content PubMed PubMed Citation Articles by Kam, K. M. Articles by Ho, N. K.

 Previous Article  |  Next Article 

Journal of Clinical Microbiology, 06 1996, 1462-1464, Vol 34, No. 6
Copyright © 1996 by the American Society for Microbiology. All rights reserved.

Detection of quinolone-resistant Neisseria gonorrhoeae

KM Kam, PW Wong, MM Cheung and NK Ho
Institute of Pathology, Sai Ying Pun Polyclinic, Department of Health, Hong Kong.

The present National Committee for Clinical Laboratory Standards (NCCLS) guideline for testing Neisseria gonorrhoeae quinolone susceptibility defines only a susceptible category for ciprofloxacin, enoxacin, lomefloxacin, and ofloxacin, while susceptible, intermediate, and resistant categories are defined for fleroxacin. To further define the criteria for detection of quinolone resistance in gonococci, by standard disk diffusion and agar dilution methodologies recommended by the NCCLS, we tested 29 strains of quinolone-resistant N. gonorrhoeae (QRNG) recently isolated from ofloxacin-treated patients who were considered clinical failures. Regression analyses were performed on these results together with those of another 20 strains showing reduced susceptibility and 13 fully susceptible strains (ofloxacin MICs of < or = 0.25 microgram/ml). With 5-micrograms ofloxacin disks, resistance in 27 (93.1%) of the QRNG strains (MICs of > 1 microgram/ml) was detected by the criterion of a zone diameter of < 22 mm, while in the remaining 2 (6.9%), the disks failed to detect resistance. A cluster of 15 highly resistant strains showed ofloxacin MICs of > 4 micrograms/ml and zone diameters of < 13 mm. When tested with 5-micrograms ciprofloxacin disks, the corresponding values for resistance and high-level resistance of these QRNG strains were < 25 mm (MICs of > 0.5 micrograms/ml) and < 15 mm (MICs of > 2 micrograms /ml), respectively. Six strains for which ofloxacin MICs were > or = 8 micrograms/ml showed no zones at all with both 5-micrograms ofloxacin and 5-micrograms ciprofloxacin disks. These QRNG strains are now firmly established in the Southeast Asia region, and it is important for clinical laboratories to recognize these clinically resistant strains and to monitor their spread.

This article has been cited by other articles:

• Hakanen, A., Kotilainen, P., Jalava, J., Siitonen, A., Huovinen, P. (1999). Detection of Decreased Fluoroquinolone Susceptibility in Salmonellas and Validation of Nalidixic Acid Screening Test. J. Clin. Microbiol. 37: 3572-3577 [Abstract] [Full Text]