Hospital superbugs increasingly resistant to disinfectants

Alcohol-based hand sanitizers and disinfectants are becoming ineffective against bacterial strains, new research revealed

The study included bacteria samples from the floors of laboratory mouse cages and found that alcohol-tolerant microbes were better able to colonise the guts of mice after the cages were cleaned with disinfectant wipes

A “new wave of superbugs” is becoming increasingly resistant to alcohol-based hand sanitizers and disinfectants, scientists in Australia have revealed.

The team studied 139 samples of multidrug-resistant Enterococcus faecium, or VRE, collected from two hospitals in Melbourne between 1997 and 2015 to see how well the bugs survived when exposed to diluted isopropyl alcohol.

They found that samples collected after 2009 were on average more resistant to the alcohol compared with bacteria taken from before 2004.

VRE bugs can cause urinary tract, wound and bloodstream infections that are difficult to treat, mainly because they are resistant to several classes of antibiotics.

Organisations worldwide have adopted stringent hygiene steps, many of them involving hand rubs and washes that contain alcohol to tackle the rise of hospital superbugs, such as VRE.

Tim Stinear, a microbiologist at Australia’s Doherty Institute who co-led the study, commented that in Australia alone, use of the alcohol-based hand hygiene has increased tenfold over the past 20 years. “So we are using a lot and the environment is changing,” he said.

The study included bacteria samples from the floors of laboratory mouse cages and found that alcohol-tolerant microbes were better able to colonise the guts of mice after the cages were cleaned with disinfectant wipes.

Paul Johnson, co-leader in the study and a professor of infectious diseases at Austin Health in Australia, warned the findings should not prompt any dramatic change in the use of alcohol-based disinfectants.

“Alcohol-based hand rubs are international pillars of hospital infection control and remain highly effective in reducing transmission of other hospital superbugs, particularly MRSA,” he said.

Stinear said health authorities should try higher-alcohol concentrate products and renew efforts to ensure hospitals are deep cleaned and patients found to be carrying VRE infections are isolated.

Their findings were published in the journal Science Translational Medicine.