Parents might one day give their children a weekly treatment with a nasal spray of virus enzymes to prevent them from getting a severe middle ear infection, based on results of a study done in mice by investigators from St. Jude Children's Research Hospital and The Rockefeller University in New York. Such a treatment would kill the disease-causing bacteria without the use of antibiotics, thereby avoiding the problem of antibiotic resistance. A report on this study appears in the March issue of the online journal "PLoS Pathogens."
Middle ear infection, also called acute otitis media, is an inflammation of the middle ear space that can cause pain, fever, irritability, lack of appetite and vomiting. The middle ear is the space just before the eardrum. About half of all children carry the bacteria that cause acute otitis media, which migrate from the nose and throat to the middle ear after an initial influenza virus infection paves the way.
The investigators based their treatment on the ability of viruses called phages to break out of bacteria they infect by using a special enzyme to destroy the cell walls. Phages infect bacteria in a way that is similar to how viruses infect animal cells. Once inside, the virus hijacks the cells biochemical machinery and forces it to make many copies of the virus. After the new crop of viruses is made, a viral enzyme breaks apart the infected bacterial cell wall and allows the new viruses to escape and infect additional cells.
The success of the new treatment, which uses a phage enzyme to kill the bacteria that cause acute otitis media, suggests that the strategy could significantly reduce the incidence of the disease in the United States, where more than 24 million cases are diagnosed yearly. Even though the current pneumonia vaccine protects against Streptococcus pneumoniaethe bacteria that cause acute otitis mediathis ear infection remains the leading cause of doctor visits and antibiotic prescript
Contact: Summer Freeman
St. Jude Children's Research Hospital