Hospital Superbug Becoming Harder to Fight With Common Disinfectants

A species of hospital superbug could be becoming better at surviving a key ingredient in disinfecting hand rubs, scientists have warned in a study.

Researchers analyzed bacteria samples collected from two Australian hospitals over a 19-year period, and found Enterococcus faecium —a leading cause of hospital infections—could be adapting to alcohol used in handwash disinfectants. These bugs are dubbed vancomycin-resistant enterococci (VRE).

Professor Timothy Stinear, co-author of the research from the University of Melbourne, told The Guardian VRE can colonize the gut and enter a patient's bloodstream. This, in turn, can trigger the deadly condition sepsis.

"It is very difficult to get rid of because it is resistant to almost all antibiotics," he said.

Following fears of the spread of the potentially deadly superbug bugs such as methicillin-resistant Staphylococcus aureus, commonly known as MRSA, healthcare facilities have adopted strict hygiene rules in a bid to protect vulnerable patients from avoidable, but deadly, infections.

Hand rubs and washes containing isopropyl alcohol are a vital tool in this fight. But rates of VRE have crept up despite these precautions, the authors noted.

The study, published by Science Translational Medicine, saw researchers test 139 samples collected between 1997 and 2015 from two hospitals in Melbourne, Australia. They then treated the bacteria with diluted isopropyl to see if they would die.

The team found the bacteria collected in 2004 suffered worse than that collected in 2009, which was more tolerant of the alcohol.

In a separate test, researchers swiped different types of E. faecium on the floors of mouse cages. After testing the animals' digestive systems, they found mice in cages cleaned with isopropyl alcohol wipes had more of the bacteria in their guts.

And an analysis of the bacteria's genetic makeup suggested the samples had gene mutations that could help protect them from alcohol.

However, the researchers caution more research is now needed to understand whether these findings relate to E. faecium in other parts of the world.

Still, Stinear told The Guardian the results should be a "wake-up call" to those on the frontline of tackling bacterial resistance to consider how microbes can adapt not just to drugs, but to ingredients in disinfectants like alcohol.

Screening patients for infections more often and using chlorine-based products rather than alcohol could be options.