STI Prophylaxis and Emergence of Antimicrobial Resistance
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- This is an observational study: the protocol does not assign a study treatment.
- Who it may be relevant to
- Registry conditions: Sexually Transmitted Infection (STI) Prevention, Antibiotic Prophylaxis, Antibiotic Resistance, Bacterial, Microbiome. Basic parameters: from 18 years · Male.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- United Kingdom
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
Unsure about the terms? Read our patient guide →
Overview
The goal of this observational study is to understand the risk of antibiotic resistance and changes in the human microbiome (bacteria that live inside and on us), if people use antibiotics to prevent sexually transmitted infections (STI prophylaxis, doxycycline post-exposure prophylaxis, or 'doxyPEP'). The study will assess how easy and acceptable it is to find antibiotic resistance and microbiome changes in the throats and guts of men-who-have-sex-with-men (MSM) who use STI prophylaxis. The study will recruit 108 MSM who are using and not using STI prophylaxis. Participants will visit the clinic every 6 months. At each visit, they will provide a throat swab and stool sample, and complete a questionnaire. DNA of the bacteria from the samples will be analysed to identify the bacteria and look for antibiotic resistance.
Primary outcome measures
- Detection of antimicrobial resistance genes of interest and characterisation of microbiome [Time frame: From enrolment to 12 months]
Secondary outcome measures (4)
- Detection of differences in prevalence of antimicrobial resistance genes of interest between people using and not using antibiotic STI prophylaxis. [Time frame: From enrolment to 12 months]
- Detection of differences in microbiome between people using and not using antibiotic STI prophylaxis. [Time frame: From enrolment to 12 months]
- Change over time in prevalence of antimicrobial resistance genes of interest between people using and not using antibiotic STI prophylaxis. [Time frame: From enrolment to 12 months]
- Change over time in microbiome between people using and not using antibiotic STI prophylaxis. [Time frame: From enrolment to 12 months]
Eligibility criteria
Inclusion criteria
- Aged ≥ 18 years.
- Identifies as a man (cis or trans).
- Has sex with men.
- Able to provide informed consent.
Exclusion criteria
- Use of an antibiotic other than doxycycline in the 3 months prior to enrolment
- Currently being treated for an STI with doxycycline
- Use of doxycycline within the prior 3 months for an indication other than STI treatment or STI prevention.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Observational model
- Cohort
Study locations
United Kingdom · 1 center
- Central and North West London NHS Foundation Trust — London
Publications
- Kohli M, Reid D, Pulford CV, Howarth A, Brown J, Mohammed H, Hughes G, Mercer CH, Saunders J. Choice of antibiotics for prophylaxis of bacterial STIs among individuals currently self-sourcing. Sex Transm Infect. 2022 Mar;98(2):158. doi: 10.1136/sextrans-2021-055310. Epub 2021 Dec 6. No abstract available. PMID 34873029
- Kohli M, Medland N, Fifer H, Saunders J. BASHH updated position statement on doxycycline as prophylaxis for sexually transmitted infections. Sex Transm Infect. 2022 May;98(3):235-236. doi: 10.1136/sextrans-2022-055425. No abstract available. PMID 35414633
- Chu VT, Glascock A, Donnell D, Grabow C, Brown CE, Ward R, Love C, Kalantar KL, Cohen SE, Cannon C, Woodworth MH, Kelley CF, Celum C, Luetkemeyer AF, Langelier CR. Impact of doxycycline post-exposure prophylaxis for sexually transmitted infections on the gut microbiome and antimicrobial resistome. Nat Med. 2025 Jan;31(1):207-217. doi: 10.1038/s41591-024-03274-2. Epub 2024 Oct 3. PMID 39363100
- Molina JM, Charreau I, Chidiac C, Pialoux G, Cua E, Delaugerre C, Capitant C, Rojas-Castro D, Fonsart J, Bercot B, Bebear C, Cotte L, Robineau O, Raffi F, Charbonneau P, Aslan A, Chas J, Niedbalski L, Spire B, Sagaon-Teyssier L, Carette D, Mestre SL, Dore V, Meyer L; ANRS IPERGAY Study Group. Post-exposure prophylaxis with doxycycline to prevent sexually transmitted infections in men who have sex PMID 29229440
- Molina JM, Bercot B, Assoumou L, Rubenstein E, Algarte-Genin M, Pialoux G, Katlama C, Surgers L, Bebear C, Dupin N, Ouattara M, Slama L, Pavie J, Duvivier C, Loze B, Goldwirt L, Gibowski S, Ollivier M, Ghosn J, Costagliola D; ANRS 174 DOXYVAC Study Group. Doxycycline prophylaxis and meningococcal group B vaccine to prevent bacterial sexually transmitted infections in France (ANRS 174 DOXYVAC): a m PMID 38797183
- Luetkemeyer AF, Donnell D, Dombrowski JC, Cohen S, Grabow C, Brown CE, Malinski C, Perkins R, Nasser M, Lopez C, Vittinghoff E, Buchbinder SP, Scott H, Charlebois ED, Havlir DV, Soge OO, Celum C; DoxyPEP Study Team. Postexposure Doxycycline to Prevent Bacterial Sexually Transmitted Infections. N Engl J Med. 2023 Apr 6;388(14):1296-1306. doi: 10.1056/NEJMoa2211934. PMID 37018493
Identifiers
NCT: NCT06778083 · 174194 · REC Ref: 24/EM/0282