Experimental vaccine may help combat Staphylococcus aureus infection
BALTIMORE, U.S.: Researchers have recently developed an experimental vaccine that protects up to 80% of mice against Staphylococcus aureus, a Gram-positive bacterium often found in the upper respiratory tract and on the skin. S. aureus has been proved to account for a third of the deadly hospital-acquired infections in patients who have just undergone a surgical procedure, including dental surgery.
According to the researchers, the vaccine has also proved to be effective in 66% of rabbits infected with S. aureus, the deadliest Staphylococcus bacterium. They believe that, although the vaccine has only been tested in animals, it has the potential to drastically reduce the number of patients who succumb to S. aureus infection post-surgery, a time when the immune system is suppressed.
“This vaccine could prove hugely beneficial, especially for orthopedic and cardiovascular patients, for example, where medical structures or devices are implanted,” said Dr. Janette Harro, a research associate in the Department of Microbial Pathogenesis at the University of Maryland School of Dentistry. “S. aureus is difficult to eradicate because it so readily forms biofilms at the surgical site,” she continued.
“Preliminary results are very promising, and we are hopeful that this vaccine will prove protective in humans as well. Dr. Harro and colleagues’ innovative research offers the potential of significantly reducing the risk of life-threatening S. aureus infections following surgery,” said Prof. Mark A. Reynolds, dean of the dental school at the university.
According to Harro, immunizing patients with a vaccine that protects against S. aureus infection before they undergo elective surgeries could significantly reduce both fatalities and health care costs.
“Biofilms, unfortunately, are very hard to treat,” Harro noted. “Antibiotics don’t work well, and the immune system can’t clear it effectively on its own.”
The Centers for Disease Control and Prevention reports that hospital-acquired infections account for about 1.7 million infections and 99,000 associated deaths each year, mostly because of their virulence and resistance to conventional antibiotics. Additionally, S. aureus costs the U.S. health care system an estimated $10 billion each year.
Young children, the elderly and patients with compromised immune systems are more susceptible to infection with S. aureus. Long-stay patients and patients who require catheters, have poor hygiene or are resistant to antibiotics are also at greater risk.
The study, titled “Clearance of Staphylococcus aureus from in vivo models of chronic infection by immunization requires both planktonic and biofilm antigens,” was published online on Dec. 17, 2019, in Infection and Immunity.