Background In the last years the Gram-negative bacterium Neisseria gonorrhoeae, already known to be resistant to penicillins, tetracyclines, macrolides and fluoroquinolones has raised attention by developing resistance and consequently treatment failures in some cases to the recommended first line treatment: extended-spectrum cephalosporins (ceftriaxone and cefixime). Therefore bacterial culture, the gold standard for definite diagnosis should be performed for antibiotic susceptibility testing, beside the widely used nucleic acid amplification testing (NAAT). However we could observe discrepancies between cefixime susceptible N. gonorrhoeae cultures and clinical treatment failures for some years.
Methods In this retrospective study, 2006–2012, clinical outcome data of patients with acute gonococcal urethritis/cervicitis, oral cefixime treatment (400mg, one dose) and cefixime susceptible N. gonorrhoeae culture were collected at the STD outpatient clinic of the Department of Dermatology and Venereology, Medical University of Graz, Austria. The diagnosis was made by microscopy (Gram or methylene blue staining), culture including antimicrobial susceptibility testing and in situ hybridization (GenProbe Pace II) of urethral/cervical swab specimens. Control urethral/cervical swaps were performed within one to two weeks.
Results Out of total 218 patients with gonorrhoea, 120 patients fulfilled the inclusion criteria. 14 of 120 (11.7%) showed a treatment failure after oral cefixime despite a positive susceptibity testing. Most treatment failures were observed in 2011 (3/11; 21.4%) and 2012 (4/17; 19%). Rates for 2007, 2008 and 2009 were 2/12; 14.3%, 3/16; 15.8% and 2/11; 15.4%. In 2006 and 2010, no treatment failure in cefixime susceptible N. gonorrhoeae infections was seen.
Conclusion Culture and antibiotic susceptibility testing remains essential in gonorrhoea management in regard of recent surveillance data suggesting that cephalosporins are becoming less effective in the treatment of gonorrhoea. Our data suggest that treatment failures with oral cefixime may occur even in infections with cefixime susceptible N. gonorrhoeae strains.
- antibiotic susceptibility testing
- cefixime treatment failure
- gonococcal urethritis