Researchers from the Doherty Institute and Monash University have developed a promising preclinical vaccine that protects against Staphylococcus aureus (golden staph), a leading cause of bloodstream and surgical infections and Streptococcus pneumoniae, which can cause pneumococcal disease such as pneumonia, sepsis and meningitis.
The study, published in Nature Microbiology, raises the possibility of a single vaccine that could protect against multiple life-threatening bacterial infections.
Many golden staph strains, including Methicillin-resistant Staphylococcus aureus (MRSA), are resistant to antibiotics. Together with Streptococcus pneumoniae, they cause more than 1.5 million deaths each year. While vaccines exist for pneumococcal disease, there is no licensed vaccine for golden staph.
With antimicrobial resistance driving an estimated one million deaths annually, vaccines are a critical long-term strategy to reduce infections and antibiotic use.
The University of Melbourne’s Jessica Braverman, a PhD student in the Wakim Laboratory at the Doherty Institute and first author of the study, said the team used immunopeptidomics, an advanced laboratory technique that identifies the tiny fragments of proteins naturally displayed on infected cells to the immune system, to uncover a previously overlooked bacterial protein.
“When we incorporated this protein known as Hup into a vaccine, it protected mice from golden staph infection,” Ms Braverman said.
“Strikingly, Hup is also found in Streptococcus pneumoniae. So, in addition to protection against golden staph, the vaccine also reduced the severity of a pneumococcal infection, with the mechanism underlying this protection yet to be fully characterised.”
“The protein organises bacterial DNA like a spool winding thread. Because the protein is shared across many dangerous bacteria, targeting it in a vaccine activates protective CD4+ T cells that have the potential to protect against a range of bacterial infections. Hup is not found in humans, making it an attractive vaccine target,” she added.
The University of Melbourne’s Professor Linda Wakim, Laboratory Head at the Doherty Institute and senior author of the study, said this new strategy focuses on generating T-cell immunity, which emerging evidence suggests is essential for controlling invasive golden staph infections.
“Because Hup is highly conserved across both Staphylococcus and Streptococcus species, a vaccine targeting this protein could potentially protect against multiple dangerous bacteria at once,” said Professor Wakim.
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