RESEARCHERS in Southampton have discovered a “hidden reservoir of bacteria” in the nose which can prevent antibiotics being effective in the treatment of chronic sinus infections.

The condition, known as chronic rhinosinusitis, leads to inflammation of the upper airways and causes a raft of problems, including catarrh, facial pain and a reduction in sense of smell.

Many patients with the condition also develop nasal polyps in their lifetime and have an increased risk of developing asthma.

It affects around 15% of the population and has a significant impact on sufferers’ quality of life as well as costing the NHS more than £100m annually on medical and surgical treatments.

Historically treatment has focused on trying to eradicate surface bacteria lining the nose and nasal sinuses with antibiotics and nasal saline irrigation.

Now, a team led by Rami Salib, a consultant ear, nose and throat surgeon at University Hospital Southampton, has found bacteria –staphylococcus aureus – which “hijack” cells in the immune system. They then use these cells to shield them from the body’s immune system.

Mr Salib said: ““This may explain why removal or elimination of the surface bacteria using antibiotics does not succeed in eradicating the infection completely in many cases.

“Surface bacteria are merely the tip of the iceberg and are simply replenished through a hidden reservoir of bacteria lurking beneath.”

Mr Salib is founder and director of the Upper Airways Research Group.

“Better understanding of intracellular bacteria and how they get there is essential in the quest for the development of treatments that can target this hidden bacterial reservoir,” he said.

“We need to start shifting our attention from surface to internal bacteria in order to improve treatment outcomes for patients with chronic rhinosinusitis, as many patients require multiple lifetime operations because medical treatment alone often fails to control the disease.”

“Development of alternative treatment strategies will also reduce reliance on antibiotics, particularly relevant nowadays with the world facing a growing epidemic of antimicrobial resistance.”