Enzyme offers hope in MRSA bug battle

An alternative to antibiotics to combat superbugs, such as MRSA, looks promising, according to a leading Irish microbiologist.

A small test study suggests a new drug, an enzyme which solely targets the bacteria in MRSA, was effective against the infection.

Scientists who made the discovery claim the likelihood of the bug becoming resistant was “very limited”. Dutch biotech firm Micreos presented the findings at the EuroSciCon meeting, called Antibiotics Alternatives for the New Millennium, in London yesterday.

In one study, the drug — Staphefekt — killed off MRSA in five out of six people suffering skin conditions, such as dermatitis and eczema.

MRSA, or methicillin-resistant staphylococcus aureus, is a potentially deadly bacteria which causes serious infections of the skin, blood, lungs and bones. It poses a serious threat in hospitals and nursing homes.

Clinical biologist Dr Bjorn Herpers, who addressed the meeting, said the results were exciting. “As well as being less prone to resistance induction than antibiotics, endolysins (enzymes) destroy only their target bacterial species, leaving the beneficial bacteria alone,” he said.

The firm is to conduct clinical trials of Staphefekt and is looking to expand them internationally.

Prof Dave Coleman from Trinity College Dublin, said it was a new approach to killing staphylococcus aureus, a species of bacteria often responsible for infection in humans and animals.

He said MRSA represented a sub-group of straphylococcus aureus that are more frequently responsible for hospital acquired infection and more recently have become a problem in the community in many countries.

The drug, Staphefekt, is based on naturally occurring enzymes called endolysins, which are found in viruses and kill bacteria in a different way to antibiotics.

Prof Coleman said it was a novel approach to treating staphylococcus aureus infection with enzymes called endolysins used to break open and kill staphylococcus aureus cells.

“This new approach has shown good potential to treat staphylococcus aureus infections and provides a valuable additional approach to combat the problem of antibiotic resistance in Saureus and MRSA.”

He said long term studies would be needed before the potential benefits of Staphefekt therapy could be fully evaluated as staphylococcus aureus and MRSA were notoriously adept at evolving and adapting to overcome new treatment agents.

And while there had been a decrease in MRSA bloodstream infections in Ireland, infections due to methicillin-susceptible staphylococcus aureus (MSSA) had remained steady.

According to the Health Protection Surveillance Centre the number of reported MRSA bloodstream infection has decreased over the last seven years — from 592 in 2006 to 222 in 2013, a reduction of 62.5%.