Last updated August 21, 2018 at 5:03 pm
Australian study has implications for hospitals worldwide.
A dangerous bacterial species is becoming increasingly tolerant to the disinfectants hospitals use to resist it, an Australian study has found.
Hospitals around the world have stringent hygienic procedures that often include the use of hand rubs and washes containing disinfectants based on isopropyl or ethyl alcohol.
However, analysis of bacterial samples taken from two Melbourne hospitals over 19 years suggests the drug-resistant species Enterococcus faecium is adapting to this approach.
Infections linked to E. faecium are actually increasing in hospitals, which prompted the team led by Dr Sacha Pidot from the Doherty Institute to try to find out if resistance was increasing.
They screened 139 E. faecium isolates – or isolated bacterial samples – collected between 1997 and 2015 and studied how well each survived when exposed to diluted isopropyl alcohol.
Mutations in genes
They found that the isolates gathered after 2009 were on average more tolerant to the alcohol compared to bacteria taken from before 2004.
The authors then seeded different isolates onto the floors of mouse cages and found that the alcohol-tolerant isolates better colonised the guts of mice housed in the cages after the cages were cleaned with isopropyl alcohol wipes.
Analysis of the bacterial genome revealed that the tolerant isolates harboured several mutations in genes involved in metabolism that conferred increased alcohol resistance. The authors say that analysis of isolates from hospitals in other geographical regions is necessary before any major conclusions can be drawn.
However, the results indicate that global efforts to mitigate bacterial resistance should consider how microbes can adapt not only to drugs but also to alcohols and other ingredients used in disinfectants.
The paper is published in Science Translational Medicine.