A clinical isolate of Neisseria gonorrhoeae with in vitro resistance to erythromycin and decreased susceptibility to azithromycin.
OBJECTIVE
Erythromycin is a recommended treatment for penicillin-allergic pregnant women with gonorrhea, and azithromycin has been suggested as therapy for coexisting gonococcal and chlamydial infections. Although gonococcal resistance to erythromycin is not uncommon, decreased resistance to azithromycin is rare. A clinical isolate of Neisseria gonorrhoeae with in vitro resistance to erythromycin and decreased susceptibility to azithromycin is reported.


METHODS
This is a case report.


RESULTS
Antimicrobial susceptibility testing of a clinical isolate of N. gonorrhoeae revealed a minimal inhibitory concentration (MIC) of 2 micrograms/ml to azithromycin and 32 micrograms/ml to erythromycin. Five hundred other urethral isolates were tested, resulting in an MIC for erythromycin ranging from 0.015 to 2 micrograms/ml. The range for azithromycin was 0.015 to 0.5 micrograms/ml. There was a strong correlation between erythromycin and azithromycin MICs (r = 0.73; P < 0.0001).


CONCLUSIONS
Continued national monitoring is needed to detect the appearance and early dissemination of new types of gonococcal resistance.
Ehret
J M
JM
Denver Public Health Department, University of Colorado Health Sciences Center, USA.
Nims
L J
LJ
Judson
F N
FN
D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D017963:Azithromycin / Q000627:therapeutic use; D002487:Centers for Disease Control and Prevention, U.S.; D004352:Drug Resistance, Microbial; D004917:Erythromycin; D006069:Gonorrhea / Q000188:drug therapy / Q000382:microbiology*; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D011159:Population Surveillance; D014481:United States
D000900:Anti-Bacterial Agents; D004917:Erythromycin; D017963:Azithromycin