A revolutionary way to combat deadly antibiotic-resistant "superbugs" has been developed by researchers at UC Davis, perhaps paving the way for a new class of drugs to supplement antibiotics.
Rather than killing the bacteria, the researchers have made an end-run around the ability of bacteria to resist antibiotics--by attacking the mechanism through which they release toxins. It is these toxins, rather than the bacterial infection itself, that destroy tissues and impair vital organs, leading to serious illness and even death.
Working with the bacterium Staphylococcus aureus, which infects as many as 500,000 hospitalized Americans a year, the researchers have identified a key protein that enables the microorganism to release its toxins. Immunizing mice with this protein protects them from the lethal effects of a staph infection, the team reports today in the journal Science.
And because the treatment does not kill the bacterium, as antibiotics do, it is unlikely that the bacterium will be able to develop resistance to it.
"This opens a whole new strategy for treating or preventing one of the most serious hospital infections we contend with," said infectious disease specialist Julie Gerberding of UC San Francisco.
Other bacteria, furthermore, almost certainly use an identical or similar mechanism for releasing their toxins, said Dr. Naomi Balaban of UC Davis, so this approach might work across a broad spectrum of infections.
"The implications are pretty enormous," said Dr. Scott Harkonen of InterMune Pharmaceuticals Inc. in Palo Alto. "We need some breakthrough approaches to controlling these infections."
Physicians have been in a life-and-death race with bacteria since penicillin was first used during World War II. As soon as researchers introduce a new antibiotic, bacteria begin developing resistance to it. Often, the useful life of an antibiotic may be as little as 10 years.
S. aureus is a particular problem, both because it can be so deadly and because it is common in hospitals. In recent years, physicians have found several strains of S. aureus that are resistant to all drugs except a powerful antibiotic called vancomycin.
Last year, they began to see infections that were resistant even to vancomycin, leaving them virtually helpless in treating patients. Even though more powerful drugs than vancomycin are in development, it appears that the mutational ability of the bacterium may be outrunning the innovations of chemists.
