A new nose drop containing "friendly" bacteria which could help prevent meningitis is being tested by UK doctors in a world-first trial.
The treatment, developed at the NIHR Southampton Biomedical Research Centre, involves a gene being inserted into a harmless form of bacteria to help it remain in the nose and prompt an immune response.
It is hoped the enhanced friendly bacteria, known as Neisseria lactamica (Nlac), will protect against its close cousin, Neisseria meningitidis (N.meningitidis), the strain responsible for causing a severe type of meningitis.
About 10% of adults carry N.meningitidis in the back of their nose and throat with no signs or symptoms.
However, in some people, it can invade the bloodstream and cause life-threatening bacterial infections, including meningitis and blood poisoning, known as septicaemia.
Meningitis occurs in people of all age groups but affects mainly infants, young children and the elderly.
Meningococcal meningitis, which is a bacterial form of the disease and is responsible for 1,500 cases a year in the UK, can cause death in as little as four hours from the onset of symptoms.
Professor Robert Read, director of the NIHR Southampton Biomedical Research Centre, said if the new research is successful it could also result in making strides to combat "other diseases caused by bacteria that breed in the nasal pathway, such as pneumonia and ear disease".