Because MRSA infections are difficult or impossible to eradicate once a biofilm is fully formed, Shirtliff is searching for a way prevent the films from growing.
The trick, he believes, is to hone in on the odd behavior of the biofilm bacteria. He has identified proteins the bacteria produce in abundance as they form a film and hopes to develop antibodies that will target those proteins.
Like an army attacking a half-built fortress, the antibodies would attack the immature biofilm and destroy it before its defenses are fully formed.
"The antibodies come in and deactivate the proteins and can destroy the biofilm," he said. "The immune cells could also come in safely then and attack as well."
To test his theories, Shirtliff grows MRSA biofilms in silicon tubing in his lab at the dental school and looks for protein targets.
Anti-biofilm vaccines he has developed have proven effective for treating rabbits with MRSA bone infections. He hopes to move on to clinical trials in humans within four years, he said.
He said a vaccine might be the best way to combat MRSA because the bacteria are so widespread. "Here in the United States," he said, "it's hard to cork that bottle."