MRSA prevention one step closer after discovery of bacterial mechanism

24 Jun 2021

Colony of Staphylococcus aureus bacteria causing skin infection. Image: © nobeastsofierce/Stock.adobe.com

In a bid to create a vaccine, scientists from GSK and Trinity have researched Staphylococcus aureus’s process of immune response disruption.

New research has revealed a trick used by the bacterium Staphylococcus aureus to thwart the immune response in the human body, and has raised hope that we are closer to a vaccine to prevent MRSA infections.

This work was carried out by immunologists from Trinity College Dublin and scientists at pharma company GSK.

In their research paper, the scientists cite Staphylococcus aureus as one of the largest healthcare threats, with a reported annual mortality rate in the US greater than that of AIDS, tuberculosis and viral hepatitis combined.

Additionally, as antibiotic resistance (AMR) in bacteria becomes more common, the efficacy of modern medicines will be reduced. The World Health Organization has declared AMR as one of the top 10 global public health threats and said the misuse and overuse of antimicrobials are the main drivers of drug-resistant pathogens.

Staphylococcus aureus is the causative agent of the MRSA ‘superbug’. Due to its antibiotic resistance, there are challenges and reduced options in the treatment of MRSA. This is why the development of a vaccine would be of particular value to healthcare practitioners.

The study from Trinity and GSK found that the bacterium interferes with the host immune response by causing toxic effects on white blood cells, preventing them from engaging in their infection-fighting jobs.

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It also showed in a pre-clinical model that the toxicity could be lessened following vaccination with a mutated version of a protein engineered to disrupt how MRSA works. If this can be replicated in vaccines for humans, researchers would be one step closer in their goal to fight MRSA.

“In this study we have identified a mechanism by which a protein made by the bacterium – known as Staphylococcal Protein A (SpA) – attacks and rapidly kills white blood cells,” Dr Rachel McLoughlin, professor in immunology at Trinity’s School of Biochemistry and Immunology and the Trinity Biomedical Sciences Institute, said.

“This protein has been widely studied for its immune evasion capacity and has a well-documented role in rendering antibodies raised against the bacterium non-functional.

“Here, we uncover a previously undocumented strategy by which SpA forms immune complexes through its interaction with host antibodies, that in turn exert toxic effects on multiple white blood cell types. This discovery highlights how important it will be for effective vaccines to be capable of disarming the effects of Protein A.”

The study is the latest advance made by the group at Trinity under an ongoing research agreement with GSK, in which PhD students from Trinity receive training in applied vaccine research in the goal of advancing both academic and industrial research.

Overall, this collaboration aims to increase understanding of the immunology of Staphylococcus aureus infection to advance the development of next-generation vaccines to prevent MRSA infections.

Sam Cox is a journalist at Silicon Republic covering sci-tech news

editorial@siliconrepublic.com