The investigation, which appears in the July 15 issue of the Journal of Clinical Investigation, focused on the bacterium Staphylococcus aureus, and its role in infections in animal tissue. S. aureus is a leading cause of serious systemic (often referred to as staph) infections and abscesses.
"Our research shows that salicylic acid, a byproduct of aspirin, impacted the stress system of the bacteria and reduced its ability to cause infection," said lead author Dr. Ambrose Cheung, a professor of microbiology and immunology at Dartmouth Medical School.
By disrupting this stress system, aspirin reduced the bacteria's capacity to adhere to host tissue. In addition, the salicylic acid disrupted the ability of S. aureus to produce toxins, which the bacteria require to propagate and spread to other tissue. As a result, the animals treated with aspirin have smaller abscesses and they have fewer number of bacteria in the infection. Aspirin did not cure it, notes Cheung, but it reduced the ability of the bacteria to cause infection.
The S. aureus bacteria are also responsible for sepsis, a blood poisoning disease that strikes 750,000 people in the US annually and is the leading cause of death in America's non-coronary intensive care units. Cases of sepsis are growing in number each year and are becoming increasingly resistant to antibiotics, making aspirin a possibly invaluable option for treatment.
"The fact that aspirin has been used for pain treatment, to reduce mortality due to heart attacks, and can possibly reduce the risks of infection is incredible," said Cheung. "We look forward to conducting future tests with aspirin in conjunction with antibiotic therapy."