Researchers supported by the National Institute of Allergy and Infectious Diseases (NIAID) have developed a vaccine that protects mice against multiple strains of Staphylococcus aureus (S. aureus), an increasingly stubborn microbe and the most common cause of hospital-acquired infections. The new vaccine is the first to be made from a bacterial molecule produced primarily during infection, rather than in laboratory culture. A report of the study by scientists at Brigham and Women's Hospital and Harvard Medical School in Boston appears in the May 28, 1999, issue of Science.
"This is an intriguing finding and a hopeful step against a very worrisome pathogen," says NIAID Director Anthony S. Fauci, M.D. "Within the last two years, S. aureus has become increasingly resistant to antibiotics. Most troubling is the emergence of strains that are partially resistant to vancomycin, our last line of defense against S. aureus. New treatments and, ideally, an effective vaccine, are urgently needed."
Each year an estimated 500,000 patients in American hospitals contract staph infections. S. aureus, the chief culprit, also is a common source of community acquired infections, and causes illnesses that range from minor skin infections and abscesses to life-threatening diseases such as severe pneumonia, meningitis, bone and joint infections, and infections of the heart and bloodstream.
Molecules isolated from bacteria grown in the laboratory have been one source of new vaccine candidates. However, since bacterial growth under laboratory conditions may not mimic an actual infection, scientists recently have begun searching for bacterial products that are activated specifically during infection.
"Presumably, these products are critical for infection and disease progression, and would therefore be logical targets for new therapeutics or vaccines," explains Gerald B. Pier, Ph.D., who led the research team that developed the new S. aureus vaccine.
Contact: John Bowersox
NIH/National Institute of Allergy and Infectious Diseases