Researchers in Southampton have discovered a “hidden reservoir of bacteria” in the nose that can prevent antibiotics being effective in the treatment of chronic sinus infections.
The condition, also known as chronic rhinosinusitis, leads to inflammation of the upper airways and causes nasal obstruction, facial pain, nasal discharge, catarrh and a reduction in sense of smell.
It affects around 15% of the population and has a significant impact on quality of life as well as healthcare costs, with more than £100m spent annually on medical and surgical treatments in the UK alone. Many patients with the condition also develop nasal polyps in their lifetime and have an increased risk of developing asthma.
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 (pictured), a consultant ear, nose and throat surgeon at University Hospital Southampton, has found bacteria – staphylococcus aureus – hidden beneath the lining of the nose and sinuses which “hijack” cells in the immune system.
They then use these cells, known as mast cells, to shield them from an immune response in the body, divide and spread and then replenish the population of surface bacteria.
“This may explain why removal or elimination of the surface bacteria using, for example, antibiotics does not succeed in eradicating the infection completely in many cases,” explained Mr Salib, an associate professor of rhinology at the University of Southampton.
“These surface bacteria are merely the tip of the iceberg and are simply replenished through a hidden reservoir of bacteria lurking beneath. Ultimately, this may explain why some infections are resistant to antibiotics and become difficult to treat.”
Mr Salib, who is founder and director of the Upper Airways Research Group at the University of Southampton, said the study, published by the Journal of Allergy and Clinical Immunology, highlighted the need to now “shift focus” onto these internal bacteria in the hope of developing novel treatments.
“Better understanding of intracellular bacteria and how they get there, which this study looked at, is essential in the quest for the development of novel treatments that can target this hidden bacterial reservoir,” he explained.
“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.”
He added: “Development of alternative treatment strategies will also reduce reliance on antibiotics, particularly relevant nowadays with the world facing a growing epidemic of antimicrobial resistance.”
Posted on Thursday 1 August 2019