The Influence of National Antibiotic Consumption on Neisseria Gonorrhoeae Antibiotic Resistance in Norway, 2003–2024

OBJECTIVES: To investigate whether national population-level antibiotic consumption influences antimicrobial resistance (AMR) in Norwegian Neisseria gonorrhoeae isolates. To explore metrics suitable for ecological AMR studies. METHODS: Longitudinal Norwegian gonococcal susceptibility data (2003-2024) were analysed alongside national antibiotic consumption. Temporal trends were examined graphically and associations assessed using one-tailed Spearman rank correlations. Novel metrics-The "Susceptible Isolate Pressure Indicator" (SIPI) and "Wild-Type Isolate Pressure Indicator" (WIPI) ratios were introduced to characterize shifts in minimum inhibitory concentration (MIC) distributions within susceptible or wild-type ranges. RESULTS: Strong positive, significant correlations were observed between consumption of the most widely used antibiotic classes in Norway-betalactamase-sensitive penicillins and tetracyclines-and gonococcal geometric mean MIC for benzylpenicillin (ρ = 0.776, P < .001) and tetracycline (ρ = 0.841, P < .001). Penicillin-class consumption was also significantly associated with betalactamase plasmid carriage (ρ = 0.637, P = .013), consistent with horizontal gene transfer from commensal flora. CONCLUSIONS: Even in a low-consumption European context, Norwegian antibiotic use appears to shape gonococcal resistance, possibly partly via gene uptake from commensal Neisseria. The SIPI and WIPI ratios describe susceptible-range MIC histogram shapes, and offer utility for AMR surveillance by capturing isolate flux.