Drug-resistant bacteria are growing tolerant to strong alcohol-based hand rubs

Over the past couple of decades the increased use of alcohol-based hand sanitizers and disinfectants in hospitals has been incredibly successful in reducing cases of deadly golden staph infections. However, a new study has found that some bacteria are now becoming resistant to these alcohol-based sanitizers. 

The research began when Professor Paul Johnson started to wonder why, when golden staph infections were decreasing, infections in another bacterial pathogen, Enterococcus faecium, were rising. Despite the rapid evolution of antibiotic-resistant superbugs, modern regimented infection controls at many hospitals have helped reduce infections over time. Johnson approached colleague Tim Stinear with the compelling hypothesis that maybe some bacteria was becoming resistant to strong alcohol-based sanitizers.

"Paul said maybe they're becoming tolerant to all the alcohols we use in our hand hygiene products," says Stinear, co-author on the recent study, "and we said, that's ridiculous. What are the chances that something could become tolerant to alcohol? It's a broad-spectrum disinfectant – it gets into the bacterial membranes and blows them apart. It's a general annihilator of cells."

The new research tested 139 different strains of Enterococcus faecium, found in Australian hospitals over a twenty year period. The bacteria was treated with an isopropanol solution, similar to the alcohol used to kill bacteria in common hand sanitizers. Strikingly the researchers found that bacterial strains collected after 2010 were 10 times more tolerant to alcohol solutions than older strains.