Doctors may soon have researchers Vincent Fischetti and Jonathan McCullers to thank for being able to offer parents an alternative treatment to traditional antibiotics for ear infections.
Every year, millions of children suffer painful earache caused by the bacterium Streptococcus pneumoniae. Tests on mice now suggest that a nasal spray containing viral enzymes called lysins might end this misery.
S. pneumoniae bacteria live harmlessly in our noses until respiratory viruses come along and disrupt the nasal membrane, allowing bacteria to migrate to the middle ear and start infections.
Bacteria-infecting viruses called phages use lysins to destroy bacterial cell walls so that they can escape and infect other cells. To show how they could destroy S. pneumoniae and prevent ear infections, Vincent Fischetti of Rockefeller University in New York and Jonathan McCullers of the St Jude Children’s Research Hospital in Memphis, Tennessee, infected mice with nasal S. pneumoniae and then treated them with a lysin spray or a mock spray containing no enzyme. When the mice were then infected with a flu virus, none of those treated with lysin developed an ear infection, while 8 out of 10 of those given the mock spray did (PLoS Pathogens, DOI: 10.1371/journal.ppat.0030028).
Importantly, the lysin that targets S. pneumoniae does not damage the harmless “commensal” bacteria that protect the ear from other infections.
New Scientist . . .