Journal Article

Stably high azithromycin resistance and decreasing ceftriaxone susceptibility in Neisseria gonorrhoeae in 25 European countries, 2016

Cole, Michelle J., Unemo, Magnus, Spiteri, Gianfranco, Day, Michaela J., Jacobsson, Susanne, Woodford, Neil, Amato-Gauci, Andrew J.

2018

Overview

Background The European Gonococcal Antimicrobial Surveillance Programme (Euro-GASP) performs annual sentinel surveillance of Neisseria gonorrhoeae susceptibility to therapeutically relevant antimicrobials across the European Union/European Economic Area (EU/EEA). We present the Euro-GASP results from 2016 (25 countries), linked to patient epidemiological data, and compared with data from previous years. Methods Agar dilution and minimum inhibitory concentration (MIC) gradient strip methodologies were used to determine the antimicrobial susceptibility (using EUCAST breakpoints) of 2660  N. gonorrhoeae isolates from 25 countries across the EU/EEA. Significance of differences compared with Euro-GASP results in previous years was analysed using Z-tests. Results No isolates with resistance to ceftriaxone (MIC > 0.125 mg/L) were detected in 2016 (one in 2015). However, the proportion of isolates with decreased susceptibility to ceftriaxone (MICs from 0.03 mg/L to 0.125 mg/L) increased significantly ( p  = 0.01) from 2015 to 2016. There were 14 (0.5%) isolates with ceftriaxone MICs 0.125 mg/L (on the resistance breakpoint), of which one isolate was resistant to azithromycin and four showed intermediate susceptibility to azithromycin. Cefixime resistance was detected in 2.1% of isolates in 2016 compared with 1.7% in 2015 ( p  = 0.26) and azithromycin resistance in 7.5% in 2016 compared with 7.1% in 2015 ( p  = 0.74). Seven (0.3%) isolates from five countries displayed high-level azithromycin resistance (MIC≥256 mg/L) in 2016 compared with five (0.2%) isolates in 2015. Resistance rate to ciprofloxacin was 46.5% compared with 49.4% in 2015 ( p  = 0.06). No isolates were resistant to spectinomycin and the MICs of gentamicin remained stable compared with previous years. Conclusions Overall AMR rates in gonococci in EU/EEA remained stable from 2015 to 2016. However, the ceftriaxone MIC distribution shifted away from the most susceptible (≤0.016 mg/L) and the proportion of isolates with decreased susceptibility to ceftriaxone increased significantly. This development is of concern as current European gonorrhoea management guideline recommends ceftriaxone 500 mg plus azithromycin 2 g as first-line therapy. With azithromycin resistance at 7.5%, the increasing ceftriaxone MICs might soon threaten the effectiveness of this therapeutic regimen and requires close monitoring.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Adolescent / Adult / Aged / Aged, 80 and over / Anti-Bacterial Agents - therapeutic use / Antibiotics / Antiinfectives and antibacterials / Antimicrobial agents / Antimicrobial resistance / Azithromycin / Azithromycin - therapeutic use / Breakpoints / Care and treatment / Cefixime / Cefixime - therapeutic use / Ceftriaxone / Ceftriaxone - therapeutic use / Child / Child, Preschool / Ciprofloxacin / Ciprofloxacin - therapeutic use / Concentration gradient / Condoms / Control / Diagnostic Tests, Routine / Dilution / Drug resistance / Drug Resistance, Bacterial - drug effects / Epidemiology / Europe / Europe - epidemiology / European Economic Area (EEA) / European gonococcal antimicrobial surveillance Programme (Euro-GASP) / European Union (EU) / Female / Gentamicin / Gentamicins - therapeutic use / Gonorrhea / Gonorrhea - drug therapy / Gonorrhea - epidemiology / Gonorrhoea / Humans / Infant / Infectious Diseases / Internal Medicine / Laboratories / Male / Medical Microbiology / Medicine / Medicine & Public Health / Microbial Sensitivity Tests / Middle Aged / Minimum inhibitory concentration / Neisseria gonorrhoeae / Neisseria gonorrhoeae - drug effects / Neisseria gonorrhoeae - isolation & purification / Parasitology / Research Article / Sentinel Surveillance / Sexually transmitted diseases / Spectinomycin / Spectinomycin - therapeutic use / STD / Surveillance / Treatment / Trends / Tropical Medicine / Young Adult