The Influence of National Antibiotic Consumption on Neisseria gonorrhoeae Antibiotic Resistance in Norway, 2003-2024.

Abstract

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. 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 characterise shifts in minimum inhibitory concentration (MIC) distributions within susceptible or wild-type ranges. 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<0.001) and tetracycline (ρ = 0.841, p<0.001). Penicillin-class consumption was also significantly associated with betalactamase plasmid carriage (ρ = 0.637, p = 0.013), consistent with horizontal gene transfer from commensal flora. 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.