New class of chemically produced antimicrobial agents could become future infection treatment alternative

Jul 20 2012

The World Health Organization (WHO) has named antimicrobial resistance one of the most important threats to human health. We therefore need to find new compounds that can be used as future alternatives to conventional antibiotics.

With her PhD project, Line Hein-Kristensen from the National Food Institute, Technical University of Denmark has, in collaboration with the Faculty of Health and Medical Sciences, University of Copenhagen, and DTU Systems Biology, demonstrated that a new class of chemically produced antimicrobial agents could become a future infection treatment alternative. These findings are another advance for researchers in the fight against antibiotic-resistant bacteria.

Antimicrobial peptides providing the platform
Line Hein-Kristensen worked with a new class of antimicrobial agents, the so-called antimicrobial peptides. Antimicrobial peptides are part of the immune system in all life forms, including humans, and constitute the first line of defence against pathogenic organisms entering the body, e.g. via the food that we eat.

Antimicrobial peptides are special in that they act differently to conventional antibiotics and may thus be active against the very bacteria that are resistant to conventional antibiotics. These also include multiresistant bacteria - for example MRSA and ESBL against which we now have only a limited arsenal of treatment options.

Synthetic compound emulating nature
Novel chemical methods have now made it possible to emulate the structure of natural antimicrobial peptides and thus also to develop many novel synthetic variants. Line Hein-Kristensen's PhD project focuses specifically on a series of synthetic compounds that have been designed, synthetised and characterised the Faculty of Health and Medical Sciences, University of Copenhagen.

The findings of her research show that the degree of antimicrobial activity against a range of food-borne and nosocomial (hospital-acquired) pathogenic bacteria depends on the chemical structure of custom-designed compounds. The research also shows that the synthetic antimicrobial peptides kill the bacteria by disrupting the bacterial cell membrane

With long-term exposure, resistance to the synthetic antimicrobial peptides may develop, but there are no current signs of cross-resistance, i.e. resistance to several different compounds with different chemical structures. This means that if bacteria become resistant to some of these compounds, other antimicrobial peptides could potentially be used for treating bacterial infections.

"If we are able to optimise the chemical structure of the synthetic compounds, we can limit the development of resistant bacteria", says Line Hein-Kristensen from the National Food Institute about the findings presented in her PhD thesis.

"We hope that one day antimicrobial peptides can become a viable alternative to conventional antibiotics", Line Hein-Kristensen adds.

Source Technical University of Denmark