MRSA vaccine breakthrough for Trinity team

Trinity College scientists believe they have identified specific cells in the immune system that may help in the development of a viable vaccine for MRSA.

The immunologists are hopeful their discovery will pave the way for a groundbreaking vaccine that will see doctors prevent blood stream infections caused by bacterium Staphylococcus aureus, rather than depend on curing the illness with medicines that are becoming less effective as infections become more resistant to antibiotics.

Staphylococcus aureus resistance to the main antibiotic used for treatment, methicillin, was first reported in the 1960s and antibiotic resistant Staphylococcus aureus — or MRSA — increased steadily in hospitals in the decades that followed.

While rates have declined slightly in recent years, Irish hospitals compare unfavourably with their European counterparts in terms of MRSA rates.

Assistant professor in immunology at Trinity, Dr Rachel McLoughlin and her colleagues found ‘T-helper type 1 cells’ were elevated in patients following Staphylococcus aureus infection.

Dr McLaughlin said their model vaccine sparks these cells into action, and improved infection outcomes.

“To design an effective vaccine it is imperative you know how a bacterium interacts with its host,” she said.

“By screening patients with Staphylococcus aureus blood stream infections we were able to isolate key players in the immune system that dealt with these infections and then designed a model vaccine that effectively sparked them into action,” Dr McLoughlin added.

She said the team’s findings will directly inform the design of anti-Staphylococcus aureus vaccines and “could significantly increase our chances of realising an effective vaccine to protect patients from MRSA”.

“This study demonstrates the importance of truly translational research,” she said.

Last year the HSE said MRSA infection levels have dropped by 62% since the executive started monitoring the number of incidences of the infection since 2006.

It said the number of MRSA bloodstream infections across the public and private hospital sector dropped from 592 in 2006 to 222 cases in 2014.

However, Health Minister Leo Varadkar admitted rates in Ireland “remain high compared to many countries”.