Staphylococcus aureus (S. aureus) is a very common skin bacteria and seems to particularly like living just inside the nose. About 20% of people carry S. aureus in their nose all the time, another 30% carry it from time to time and another 50% of people never carry it.
Currently we can’t explain why, but variation in human genes, lifestyle, and the presence of other bacteria in the nose may all have a role to play.
For most people, carriage of S. aureus is harmless. However, a small number of people are susceptible to S. aureus infections due to a weakened immune system and, in some cases, these infections may be serious and resistant to antibiotic treatment. Understanding why only some people are carriers while others aren’t will help design new ways to prevent and treat such infections.
We propose to conduct a very large study to understand what determines the carriage of S. aureus in humans. One way to see if a person carries S. aureus is to analyse swabs taken from the nose. We are uncertain of the acceptability of collecting nasal swabs in large groups of volunteers. Therefore before we conduct a study in large numbers of people, we are doing a small preliminary study in about 2,250 blood donors to see if nasal self-swabbing is acceptable.