NEW YORK, May 27 (Reuters Health) -- Boston researchers have found a molecule on the surface of Staphylococcus aureus that may serve as the basis of a vaccine against infections caused by the bacterium, according to a report in the May 28th issue of the journal Science.
Staph aureus is a common cause of infections, and some strains of the bacteria have developed resistance to common antibiotics -- which means that these antibiotics can no longer be used to treat such infections. A vaccine "could sidestep the resistance problem by preventing infections from the outset," according to a statement issued by Science.
"Essentially, we have come up with a possible vaccine for a broad range of Staph infections," lead researcher David McKenney, a research fellow at Brigham and Women's Hospital in Boston, Massachusetts, told Reuters Health.
In their study, the researchers identified a large polysaccharide, or sugar molecule, called PNSG on the surface of Staph aureus. The molecule is thought to play a role in the first steps of Staph infections, as the bacteria enter cells.
The investigators found that animals immunized against PNSG were protected against Staph aureus infections.
McKenney and colleagues report that in studies conducted in mice and rabbits, the vaccine was effective against eight strains of Staph infection, including the strain responsible for life-threatening toxic shock syndrome, certain hospital-acquired wound infections and strains resistant to the antibiotic vancomycin, currently the last resort for treating staph infections, he said.
"We have developed a vaccine that potentially will protect people against all stubborn staph infections, including strains of these bacteria that have recently been shown to be highly resistant to antibiotics," explained study co-author Dr. Gerald B. Pier, of Brigham and Women's Hospital, in a written statement.
"Our findings are very timely because the resilient 'superbug' staph infections threaten to return medicine to the pre-antibiotic era where little could be done for patients with serious bacterial infections," added Pier, also a professor of medicine at Harvard Medical School in Boston.
If further studies corroborate the findings, "the vaccine may help protect newborns with fragile immune systems in hospitals from staph infections, and there is a long-term possibility of using it as a general vaccine that can be given to kids when they receive other vaccines," McKenney told Reuters Health.
Staph infections, caused by both Staphylococcus aureus and Staphylococcus epidermis, are diagnosed in more than 500,000 people in the United States each year, added McKenney.
SOURCE: Science 1999;284:1523-1526.
