New way for humans to fight hospital superbugs

28 Jul 2011

Researchers at DCU and Trinity College Dublin have identified a novel mechanism in the immune system that will enable humans to defend themselves against hospital superbug Clostridium difficile, which has three times higher mortality rates than MRSA.

A new study jointly led by senior lecturer in Immunology, Dr Christine Loscher of Dublin City University and professor of medicine Dermot Kelleher of Trinity College Dublin, has identified a novel mechanism by which humans can defend themselves against Clostridium difficile.

The study provides critical information for the development of therapies for the treatment of the infection caused by this bacterium. Furthermore, it has unveiled one of the reasons why some patients are highly susceptible to this bacterium and go on to develop severe infections.

In the past two decades, the incidence of Clostridium difficile infection (CDI) has increased dramatically and the impact of CDI in healthcare settings is considerable in terms of mortality, morbidity and disease management. The increase in mortality rates, which in some countries are now three times that of MRSA, has been largely attributed to the emergence of strains of C difficile with increasing virulence and antibiotic resistance and enormous resources are now occupied in the prevention and treatment of this condition.

The new research, which has just been published in the prestigious journal PLOS Pathogens, has shown that the immune system is able to recognise proteins which are found on the outside of the bacterium. The recognition of these surface layer proteins trigger an important receptor of the immune system, known as TLR4, which then instructs the immune system to destroy the bacterium and therefore provides protection for the human host.

A major step forward

“This is a major step forward in the battle against this superbug, which provides us with a new understanding of how the immune system responds to Clostridium difficile in humans,” said Loscher. “This is the vital information we need in order to design ways to help patients fight this infection.”

Kelleher added: “Clostridium difficile is an increasingly important health problem and this new finding will help us to understand why certain patients get infected and also what novel therapeutic strategies might be important in boosting host immunity in susceptible individuals.”

The work was supported by grants from Science Foundation Ireland and Enterprise Ireland. Other researchers involved in this work include Prof Padraic Fallon at TCD, Prof Luke O’Neill at TCD, Dr Mary O’Connell at DCU and Dr Thomas Rogers at St James’s Hospital, Dublin.

John Kennedy is a journalist who served as editor of Silicon Republic for 17 years