Analysis of minimum inhibitory concentrations of azithromycin, ceftriaxone and ciprofloxacin for Neisseria gonorrhoeae from antimicrobial resistance sentinel surveillance, Germany, 2014 to 2023.

BACKGROUNDNeisseria gonorrhoeae (NG), the pathogen causing the sexually transmitted infection (STI) gonorrhoea, shows increasing antimicrobial resistance threatening recommended treatments.AIMWe examined temporal trends in antibiotic susceptibility of NG isolates in Germany and possible shifts in sexual networks.METHODSWe analysed annual data from the German antimicrobial resistance sentinel surveillance programme Go-Surv-AMR (2014-2023). Isolates were tested by E-test for phenotypic susceptibility to azithromycin (AZM), ceftriaxone (CRO) and ciprofloxacin (CIP) to determine minimum inhibitory concentrations (MIC). We described patient demographics and calculated MIC metrics by year, sex, age group and specimen type. We assessed differences in yearly MIC distributions using Kolmogorov-Smirnov tests and analysed temporal trends by fitting beta distributions to log-transformed MIC by antibiotic and epidemiological group.RESULTSWe collected 5,421 NG isolates from across Germany, primarily from males (n = 4,704) and from urethral specimens (n = 4,060). From 2016 to 2023, median AZM MIC nearly quadrupled in female and male isolates (0.12-0.45 mg/L). Median CRO MIC remained low overall (≤ 0.009 mg/L) but increased significantly in males in 2022-2023, especially in extragenital/screening isolates. Median CIP MIC increased (0.003-0.0057 mg/L), most pronounced in male extragenital/screening isolates.CONCLUSIONAcross the examined decade, NG showed subtle increases in MIC in extragenital/screening isolates from males, possibly reflecting decreasing antibiotic susceptibility in groups that regularly undergo STI screening. Rising AZM MIC suggests early spread of resistant strains. This highlights the need for continued surveillance, consistent susceptibility testing, targeted education for vulnerable groups, promotion of condom use, and potential vaccination.