ReSET Rechallenge S.aureus Experimental nasal colonisation study v1.0
Research type
Research Study
Full title
A staged dose-finding and challenge/rechallenge study of Staphylococcus aureus nasal colonisation in healthy adults
IRAS ID
366748
Contact name
Andrew Pollard
Contact email
Sponsor organisation
Research Governance, Ethics and Assurance (RGEA), University of Oxford
Duration of Study in the UK
3 years, 8 months, 31 days
Research summary
All people naturally carry many different types of bacteria on and inside their bodies. Most of these bacteria are harmless and simply live alongside us as part of our “normal flora” – this is called colonisation. One such bacterium is Staphylococcus aureus, which commonly lives on the skin and, in particular, inside the nose. About three in ten people carry it all the time, whilst others seem to carry it only occasionally or not at all.
Although Staphyloccocus aureus usually causes no problems, it is medically important because it can sometimes lead to infection. These range from minor skin infections to serious, life-threatening illnesses such as bloodstream infections (sepsis). People who already carry the bacterium in their nose are more likely to develop an infection, especially if they have higher amounts of the bacterium. In most cases, colonisation happens before infection develops.
By learning more about colonisation – how it begins, how long it lasts, and how the number of bacteria changes over time – we can understand how infections start and how to prevent them.
In our study, we aim to discover why Staphylococcus aureus can live in some people’s noses but not in others’. To do this, we will use an approach called a Controlled Human Infection Model (or “challenge”), where a small amount of the bacterium is placed into volunteers’ noses. The volunteers are then monitored closely to make sure they stay safe.
We will test different types of Staphylococcus aureus, called strains, and measure how much bacteria is needed for colonisation to occur and collect samples to understand why some people become colonised whilst others do not.
When we know which strain of the bacteria to use and how much we need, we will ‘challenge’ volunteers again to see whether being colonised once offers any protection against becoming colonised again.
Developing this safe and informative model will help researchers test new ways – including possible vaccines – to prevent Staphylococcus aureus infections in the future.REC name
South Central - Berkshire Research Ethics Committee
REC reference
26/SC/0123
Date of REC Opinion
24 Apr 2026
REC opinion
Favourable Opinion