Imagine falling seriously ill with an infection. Normally, we visit the doctor, are prescribed antibiotics, and after 7-10 days, we're back on our feet. But today, it is no longer guaranteed that the treatment will work. Infections like pneumonia, tuberculosis, or blood poisoning are becoming increasingly difficult to treat, and according to the World Health Organization (WHO), millions of lives could be lost if we don’t find a solution to the so-called MRSA bacteria, that can’t be treated with antibiotics.
When bacteria manage to resist antibiotic treatment, it is often because the bacteria form a biofilm of proteins and sugars that acts as a shield against the antibiotic. And it is a part of the biofilm defence structure that researchers have now decoded in a new study, explains Maria Andreasen, Associate Professor at the Department of Biomedicine at Aarhus University, who is one of the researchers behind the study:
“We have decoded the molecular structure of an important part of a bacterium called S. aureus. This is the first detailed insight into how these specific molecules form their macrostructure. By understanding the structures and how the biofilm forms, we can develop new strategies and treatment methods and perhaps even prevent the bacteria from forming the biofilm altogether.”
Although the focus is on molecular cell structures, the researchers are addressing a much larger and far-reaching problem. According to a 2022 study, 1.27 million people globally died in 2019 directly due to infections from antibiotic-resistant bacteria.
This is why the findings from the Aarhus University and University of Pittsburgh study are significant, says Maria Andreasen.
“For the first time, we have identified the structure of the entire protein from the MRSA biofilm. Now, we can focus our research on how we might use this knowledge to find or develop molecules that prevent the biofilm from forming. If we succeed, it will be easier to treat infections and combat the growing antibiotic resistance,” she says.
If the research team, which also includes researchers from the University of Pittsburgh in the USA, can break down or prevent the formation of the protective biofilm, it will be a crucial step towards treating resistant MRSA infections.
MRSA stands for Methicillin-resistant Staphylococcus aureus. It is a type of bacteria that has developed resistance to many common antibiotics, including methicillin, penicillin, and similar drugs. Here are some key points about MRSA:
Researchers from the Department of Biomedicine at Aarhus University, together with researchers at the University of Pittsburgh, have decoded the molecular composition of an important part of the S. aureus biofilm, specifically the aggregated form of PSMα1, which is a functional amyloid. This contributes to forming a protective biofilm that makes the bacterium resistant to antibiotic treatment.
A lot more research is needed. However, understanding the precise structure of the molecular composition means that researchers are one step closer to either preventing the biofilm from forming or developing treatments that can penetrate it.
Study type: The project is fundamental research conducted mainly using cryo-electron microscopy, supplemented with fluorescence spectroscopy and NMR (nuclear magnetic resonance).
Collaborating partners: University of Pittsburgh (Umit Akbey, James F. Conway) and from iNano at Aarhus University (Thomas Boesen and Taner Drace).
External funding: The project received external funding from the University of Pittsburgh School of Medicine, Aarhus University Research Foundation, and the Danish National Cryo-EM Facility.
Disclosure of potential conflicts of interest: None.
Read more in the scientific article: https://www.pnas.org/doi/abs/10.1073/pnas.2406775121 <
Associate Professor Maria Andreasen
Aarhus University, Faculty of Health, Department of Biomedicine
Email: mariaj@biomed.au.dk
Phone: +45 24 21 14 21
Proceedings of the National Academy of Sciences
Experimental study
Cells
Structure of biofilm-forming functional amyloid PSMα1 from Staphylococcus aureus
8-Aug-2024
Disclosure of potential conflicts of interest: None.