STI Prophylaxis and Emergence of Antimicrobial Resistance (SPEAR)

March 26, 2025 updated by: University College, London

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.

Study Overview

Status

Recruiting

Conditions

Study Type

Observational

Enrollment (Estimated)

108

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • United Kingdom
      • London, United Kingdom
        • Recruiting
        • Central and North West London NHS Foundation Trust
        • Contact:
        • Principal Investigator:
          • Manik Kohli

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

Men-who-have-sex-with men aged ≥ 18 years living in the United Kingdom. Target of 108 participants, with minimum 40 participants living with HIV.

Description

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.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
DoxyPEP users
Previous use of doxycycline post-exposure prophylaxis within 3 months of baseline visit.
Doxycycline treatment

Previous use of doxycycline for STI treatment within 3 months of baseline visit.

Once enrolled all participants may use doxycycline post-exposure prophylaxis.
No antibiotics
No antibiotics within previous 3 months of baseline visit. Once enrolled all participants may use doxycycline post-exposure prophylaxis.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Detection of antimicrobial resistance genes of interest and characterisation of microbiome
Time Frame: From enrolment to 12 months
The successful detection of antimicrobial resistance genes of interest (tetracycline and other antibiotic classes) and identification of bacterial species (microbiome) and in the oropharynx and gastrointestinal tract.
From enrolment to 12 months

Secondary Outcome Measures

Outcome Measure
Time Frame
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
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
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
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
From enrolment to 12 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University College, London

Collaborators

University of Oxford

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 10, 2025

Primary Completion (Estimated)

April 30, 2027

Study Completion (Estimated)

April 30, 2027

Study Registration Dates

First Submitted

January 10, 2025

First Submitted That Met QC Criteria

January 10, 2025

First Posted (Actual)

March 25, 2025

Study Record Updates

Last Update Posted (Actual)

March 27, 2025

Last Update Submitted That Met QC Criteria

March 26, 2025

Last Verified

March 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 174194
  • REC Ref: 24/EM/0282 (Other Identifier: NHS Health Research Authority)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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