Novel treatments to fight yeast infections just round the corner
Researchers led by Imperial College London in the United Kingdom have uncovered the mystery of how yeast cells identify and attach to human tissue, which eventually leads to infection. The findings of the study, published in the journal Proceedings of the National Academy of Sciences (PNAS), could lead to the development of a new class of medicines and vaccines to fight drug-resistant and deadly strains of fungal infections.
Yeast infections rank fourth on the list of common cause of infection acquired by hospital patients. When healthy people are affected, it is usually associated with vaginal or oral yeast infections, commonly known as thrush. But extreme cases in vulnerable patients usually are the result of yeasts that circulate in the bloodstream and find their way throughout the body, leading to systemic candidiasis. The spread of this infection significantly jeopardises the life of patients.
In their study, the researchers discovered how yeast cells identify and attach to human tissue so that they can colonise it and trigger an infection. They also determined how this process works. This latest information could lead to the creation and testing of new prototype drug-like molecules that obstruct the yeast and ensure that infection does not emerge.
While existing medications can suppress yeast infections and eliminate them from medical equipment, the microorganisms have the ability to get the better of current treatments. A number of strains of yeast have already become fully resistant to antifungal treatments. Researchers are working at finding new ways to prevent infection.
'Most healthy women will have thrush or other mild yeast infection at some point in their lives, but what is less well known is that yeasts can be lethal, and a major health concern for vulnerable hospital patients,' explains Dr Paula Salgado, one of the main investigators who carried out the research, from the Department of Life Sciences at Imperial College London. 'What I find most concerning is the fact that we don't seem to have an effective way to control the most severe cases of these infections. Our work allows us to understand the details involved and provide vital clues to develop new drugs and clinical applications.'
Dr Ernesto Cota and colleagues used data generated by high field magnets in the Nuclear Magnetic Resonance (NMR) Centre at Imperial College London in addition to large X-ray research facilities across Europe to investigate the Als adhesion protein on the surface of the yeast Candida albicans so as to determine how it influences the yeast's capacity to recognise human tissues.
They examined the structure of this fungal protein, pinpointing the part of Als adhesion that attaches the yeast cell to human tissues and determining that interaction's components.
'We have shown the unique way that Candida albicans has evolved to recognise and latch on to a wide variety of human cells,' Dr Cota says. 'Als adhesion proteins give the yeast an ability to thrive throughout the human body, which is what makes it such a dangerous infection. We hope this new knowledge will allow us to create drug-like molecules that prevent the yeast cells from taking hold, by blocking this specific molecular mechanism.'
Researchers from the University of Illinois at Urbana-Champaign in the United States contributed to this study.