New discovery to prevent infections spreading on medical devices

Posted on: 20 March 2017

Microbiologists from Trinity College Dublin have discovered how to prevent bacteria from growing on medical devices such as hip replacements and heart valves that are implanted in the human body.

Their discovery is a step towards developing new preventative strategies that could have a direct impact on the recovery of patients in the immediate aftermath of a surgical operation.

Medical devices are routinely used in modern medicine to prevent and treat illness and disease but their use is compromised when an accumulation of bacteria called “biofilms” attach to the device surface after it is implanted in the human body.

Communities of these bacteria called 'staphylococci' grow on catheters, heart valves and artificial joints, and avoid being killed by antibiotics and the human immune system, which means healthcare professionals often have to remove and replace the medical devices. Each incident of biofilm infection costs the healthcare system €50,000 – €90,000.

The research team — led by Dr Joan Geoghegan, Assistant Professor of Microbiology in Trinity’s School of Genetics and Microbiology — is studying new ways to prevent medical device-related infection. 

Their recent breakthrough published in the prestigious journal Proceedings of the National Academy of Sciences of the USA shows that it is possible to prevent communities of staphylococci from forming by targeting the linkages that hold the bacteria together.

In collaboration with atomic force microscopy expert Professor Yves Dufrêne and his team at the Université Catholique de Louvain, Leanne Hays, PhD student in Trinity’s Department of Microbiology, has found that it is possible to stop bacteria from attaching to surfaces and to each other by using a small blocking molecule. 

The target of the blocking molecule was a protein attached to the surface of the bacteria called 'SdrC'. In laboratory experiments the blocking molecule prevented the SdrC protein from recognising other bacteria, which stopped the staphylococci from growing as biofilm communities.   

Dr Geoghegan said: “These new findings show that it is possible to stop bacteria from building communities using molecules that specifically target proteins attached to the surface of the bacteria. This exciting breakthrough will inform the design of new, targeted approaches to prevent biofilm formation by staphylococci and reduce the incidence of medical device-related infection.“

The research at Trinity College Dublin was supported by an Irish Research Council Government of Ireland Postgraduate Scholarship awarded to Leanne Hays.