Antimicrobial resistance in <i>Neisseria gonorrhoeae</i> among men who have sex with men: a 10-year analysis with implications for doxycycline post-exposure prophylaxis.

The implementation of HIV pre-exposure prophylaxis and doxycycline post-exposure prophylaxis may influence antimicrobial resistance in Neisseria gonorrhoeae among men who have sex with men (MSM). We examined trends in antimicrobial resistance among MSM, stratified by HIV and PrEP status, and assessed tetracycline resistance in relation to doxyPEP use. We included all MSM with an N. gonorrhoeae isolate at Melbourne Sexual Health Centre (MSHC) between 2015 and 2024. Resistance was defined using 2025 EUCAST breakpoints and epidemiological cutoff values. Trends were assessed using the Cochran-Armitage test, and tetracycline resistance was compared between doxyPEP users and non-users using the chi-square test. A total of 11,334 isolates from 6,611 MSM were included. Ceftriaxone resistance remained rare (3/11,334; 0.03%). The proportion of isolates with acquired azithromycin resistance mechanisms increased from 0.9% (8/940) in 2015 to 6.4% (102/1,584) in 2024 (Ptrend Ptrend P = 0.003). High-level tetracycline resistance (MIC > 8 mg/L) was also more common among doxyPEP users (54.2% vs 29.7%, P Neisseria gonorrhoeae is an urgent global health threat, and the expanding use of doxyPEP among MSM has raised concerns regarding its selective pressure on resistance. Linking a decade of individual-level clinical data to over 11,000 isolates from a major Australian sexual health clinic, we show that the proportion of azithromycin non-wild-type has risen to 6.4%, surpassing the 5% threshold at which the WHO recommends discontinuing an agent for empirical therapy. This finding raises concerns about the ongoing utility of dual ceftriaxone-azithromycin treatment. Furthermore, tetracycline resistance was significantly higher among doxyPEP users, with a disproportionate increase in high-level resistance (MIC >8 mg/L) that was associated with ciprofloxacin co-resistance. These findings provide timely real-world evidence to inform gonorrhea treatment guidelines and antimicrobial surveillance as doxyPEP implementation expands globally.

The implementation of HIV pre-exposure prophylaxis and doxycycline post-exposure prophylaxis may influence antimicrobial resistance in Neisseria gonorrhoeae among men who have sex with men (MSM). We examined trends in antimicrobial resistance among MSM, stratified by HIV and PrEP status, and assessed tetracycline resistance in relation to doxyPEP use. We included all MSM with an N. gonorrhoeae isolate at Melbourne Sexual Health Centre (MSHC) between 2015 and 2024. Resistance was defined using 2025 EUCAST breakpoints and epidemiological cutoff values. Trends were assessed using the Cochran-Armitage test, and tetracycline resistance was compared between doxyPEP users and non-users using the chi-square test. A total of 11,334 isolates from 6,611 MSM were included. Ceftriaxone resistance remained rare (3/11,334; 0.03%). The proportion of isolates with acquired azithromycin resistance mechanisms increased from 0.9% (8/940) in 2015 to 6.4% (102/1,584) in 2024 (Ptrend Ptrend P = 0.003). High-level tetracycline resistance (MIC > 8 mg/L) was also more common among doxyPEP users (54.2% vs 29.7%, P Neisseria gonorrhoeae is an urgent global health threat, and the expanding use of doxyPEP among MSM has raised concerns regarding its selective pressure on resistance. Linking a decade of individual-level clinical data to over 11,000 isolates from a major Australian sexual health clinic, we show that the proportion of azithromycin non-wild-type has risen to 6.4%, surpassing the 5% threshold at which the WHO recommends discontinuing an agent for empirical therapy. This finding raises concerns about the ongoing utility of dual ceftriaxone-azithromycin treatment. Furthermore, tetracycline resistance was significantly higher among doxyPEP users, with a disproportionate increase in high-level resistance (MIC >8 mg/L) that was associated with ciprofloxacin co-resistance. These findings provide timely real-world evidence to inform gonorrhea treatment guidelines and antimicrobial surveillance as doxyPEP implementation expands globally.