Antimicrobial resistance in Neisseria gonorrhoeae among men who have sex with men: a 10-year analysis with implications for doxycycline post-exposure prophylaxis
8 affiliations
- 1Melbourne Sexual Health Centre, Bayside Health, Melbourne, Victoria, Australia
- 2School of Translational Medicine, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Victoria, Australia
- 3Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology & Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
- 4Department of Infectious Diseases & Immunology, Austin Health, Heidelberg, Victoria, Australia
- 5Centre for Pathogen Genomics, University of Melbourne, Melbourne, Victoria, Australia
- 6Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
- 7Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
- 8Department of Infectious Diseases, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
Abstract
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 < 0.001), above the 5% level at which the WHO recommends that an antimicrobial no longer be used for empirical treatment. Ciprofloxacin resistance increased substantially, from 18.5% (170/920) to 55.2% (875/1,584) (Ptrend < 0.001), with significant trends in all three groups. Tetracycline resistance, assessable from 2019 onward, was consistently high (around 80%), with no significant trend. Among 1,020 isolates with known doxyPEP status, tetracycline resistance was significantly higher in doxyPEP users than in non-users (89.2% [107/120] vs 77.2% [695/900], P = 0.003). High-level tetracycline resistance (MIC > 8 mg/L) was also more common among doxyPEP users (54.2% vs 29.7%, P < 0.001). Ceftriaxone remains effective for empirical gonorrhea treatment among MSM in Melbourne. Rising the proportion of azithromycin non-wild-type raises concerns about its ongoing utility in dual therapy. Higher tetracycline resistance among doxyPEP users, particularly high-level tetracycline resistance, underscores the need to monitor for multidrug-resistant strains as doxyPEP use expands.
IMPORTANCE: Antimicrobial-resistant 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.
Related
- Less is more: reconsidering asymptomatic Chlamydia trachomatis and Neisseria gonorrhoeae screening for gay, bisexual and other men who have sex with men in the era of doxycycline post-exposure prophylaxis (DoxyPEP)
- Rifaximin Versus Norfloxacin for Secondary Prophylaxis of Spontaneous Bacterial Peritonitis in the Era of Antimicrobial Resistance: A Systematic Review and Meta-Analysis with Missing-Data Sensitivity Analyses
- Molecular typing and characterisation of antimicrobial resistance determinants of Neisseria gonorrhoeae among symptomatic individuals in the Eastern Cape, South Africa
- Awareness and Prescribing Practices for Doxycycline Post‐Exposure Prophylaxis (doxyPEP) Among Healthcare Providers Delivering Sexual Health Care in Australia: A Cross‐Sectional Survey
- Temporal Trends in Antimicrobial Resistance Among Clinically Important Pathogens in Iraq, 2021-2024: Implications for Empirical Antimicrobial Therapy
BibTeX
@article{latt2026antimicrobial,
title = {{Antimicrobial resistance in Neisseria gonorrhoeae among men who have sex with men: a 10-year analysis with implications for doxycycline post-exposure prophylaxis}},
author = {Phyu Mon Latt and Ei T. Aung and Nyi Nyi Soe and Norelle L. Sherry and Ivette Aguirre and Vesna De Petra and Fabian Y. S. Kong and Eloise Williams and Paula Roydhouse and Eric P. F. Chow},
journal = {Journal of Clinical Microbiology},
year = {2026},
month = sep,
doi = {10.1128/jcm.00965-26},
url = {https://doi.org/10.1128/jcm.00965-26},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Antimicrobial resistance in Neisseria gonorrhoeae among men who have sex with men: a 10-year analysis with implications for doxycycline post-exposure prophylaxis
AU - Phyu Mon Latt
AU - Ei T. Aung
AU - Nyi Nyi Soe
AU - Norelle L. Sherry
AU - Ivette Aguirre
AU - Vesna De Petra
AU - Fabian Y. S. Kong
AU - Eloise Williams
AU - Paula Roydhouse
AU - Eric P. F. Chow
PY - 2026
DA - 2026/09/25
JO - Journal of Clinical Microbiology
DO - 10.1128/jcm.00965-26
UR - https://doi.org/10.1128/jcm.00965-26
AB - 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 < 0.001), above the 5% level at which the WHO recommends that an antimicrobial no longer be used for empirical treatment. Ciprofloxacin resistance increased substantially, from 18.5% (170/920) to 55.2% (875/1,584) (Ptrend < 0.001), with significant trends in all three groups. Tetracycline resistance, assessable from 2019 onward, was consistently high (around 80%), with no significant trend. Among 1,020 isolates with known doxyPEP status, tetracycline resistance was significantly higher in doxyPEP users than in non-users (89.2% [107/120] vs 77.2% [695/900], P = 0.003). High-level tetracycline resistance (MIC > 8 mg/L) was also more common among doxyPEP users (54.2% vs 29.7%, P < 0.001). Ceftriaxone remains effective for empirical gonorrhea treatment among MSM in Melbourne. Rising the proportion of azithromycin non-wild-type raises concerns about its ongoing utility in dual therapy. Higher tetracycline resistance among doxyPEP users, particularly high-level tetracycline resistance, underscores the need to monitor for multidrug-resistant strains as doxyPEP use expands. IMPORTANCE: Antimicrobial-resistant 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.
SN - 0095-1137
SN - 1098-660X
ER -