It may be possible to prevent middle ear infections using a viral protein, US scientists believe.
Most middle ear infections are not serious
In mice, the lysin treatment killed off bacteria known to cause otitis media or infections of the middle ear - the part that lies behind the eardrum.
Although most middle ear infections are not serious, most young children experience them and they can cause considerable pain and discomfort.
Lysins could be a good alternative to antibiotics, PLoS Pathogens reports.
Antibiotics are effective, but there is the issue of resistance - bacteria can learn how to evade attack, say the study authors.
The bacteria that cause middle ear infections - Streptococcus pneumoniae - reside in the nose and cause a problem really only when a child catches another infection like the flu.
When this happens, the bacteria seize the opportunity and migrate to the middle ear and take hold.
Lysin kills the bacteria before they can cause a secondary ear infection.
The tests in mice showed lysin treatment was 100% effective at preventing otitis media and eliminated the Strep infection 90% of the time.
Lead researcher Dr Vincent Fischetti, from Rockefeller University, said: "It is really a no-brainer.
"If the bacteria aren't there, they cannot cause the secondary infection."
He teamed up with experts from St Jude Children's Hospital.
David Bowdler, consultant ENT surgeon and otologist at University Hospital Lewisham, said: "It holds potential promise. But it's far too early to predict whether there will be any significant benefit from it."
Michael Wareing, an ENT expert at Barts and the London NHS Trust, pointed out that most cases of acute otitis media settle down on their own and are viral, so do not require antibiotics.
The mainstay of treatment is pain relief with analgesia like paracetamol.
A collection of sticky fluid, called glue ear, can also develop and affect hearing. The blockage may need draining with the use of grommets.