'Bug' spray cuts risk of ear infection

Science News, Feb 3, 2001 by J. Raloff

Swedish researches are spearheading a truly counterintuitive approach to heading off recurrent ear infections in youngsters. They're spraying bacteria into children's noses.

Roughly 1 in every 20 kids is prone to ear infections, also known as otitis media. From infancy through their toddler years, these children can average six or more bouts annually.

Ironically, the antibiotics used to treat these bacterial infections often wipe out beneficial bacteria that would otherwise compete with, or even kill, the pathogens. By replacing some of the depleted germ-inhibiting bacteria, a researcher at Lundby Hospital in Gothenburg hoped to turn this situation around.

Kristian Roos and his coworkers started by formulating solutions charged with five species of beneficial alphastreptococcus bacteria that had been harvested from the eustachian tubes of healthy children at a day care center. These tubes, which connect the nasopharynx and middle ear, provide a conduit through which germs in the nose and throat can infect ears.

Next, the researchers recruited 130 children who had a history of frequent bouts of otitis media and were just about to start a course of antibiotics for their latest infection. Their parents were told to administer a nasal spray twice daily for 10 days, beginning as soon as the antibiotic treatment had ended. Half the youngsters received sprays with the bacteria-laced solution; the rest got a bacteria-free spray. The parents were asked to administer a second course of nasal sprays 1 month later.

At the end of 3 months, 42 percent of the children getting the bacterial spray remained free of ear infections, compared with just 22 percent of the children who received the microbefree spray. Moreover, any ear secretions from otitis media were more likely to vanish without further treatment in children getting the bacterial spray than in the other. The findings appear in the Jan. 27 BRITISH MEDICAL JOURNAL.

The trial follows a similar success by Roos' team in battling recurrent tonsilitis. They recolonized kids' pharnyx, the passage between the mouth and esophagus, with alpha-streptococci.

Although these are the first ear-nose-and-throat recolonization tests in people, a conceptually similar approach has been tried in animal, notes microbiologist Robin Anderson of the Agricultural Research Service Food and Feed Safety Research Unit in College Station, Texas. That group developed Preempt, which seeds the guts of young animals with beneficial bacteria to exclude later infection with food-poisoning germs (SN: 3/28/98, p. 196).

Though the Swedish work is in an early phase, it shows potential "to reduce our dependence on antibiotics," Anderson says.

The "exciting" human data indicate that people "can no longer ignore the beneficial role many bacteria are playing in secretory passages of the body," adds Trevor Tomkins of Milk Specialties Co. in Dundee, Ill., which markets Preempt.