Evolving superbug can thrive in hospitals and on sugary Western diet

A diarrhoea-causing superbug has evolved to spread in hospitals and evade measures to stop it, scientists say.

Genetic changes in the newly emerging species of Clostridium difficile (C diff) mean it has a sweet tooth that allows it to thrive in the sugar-rich Western diet.

It is also able to sidestep common hospital disinfectants.

Scientists say the bacteria was primed to take advantage of modern healthcare practices and human diets, before hospitals existed.

The gut-infecting bacterium C difficile is evolving into two separate species, with one group highly adapted to spread in hospitals, according to a new study.

Researchers at the Wellcome Sanger Institute, London School of Hygiene and Tropical Medicine and collaborators estimate this emerging species started to appear thousands of years ago.

Causing debilitating diarrhoea, it is thought the superbug accounts for more than two- thirds of healthcare C diff infections.

C diff bacteria can infect the gut and are the leading cause of antibiotic-associated diarrhoea worldwide.

Published in Nature Genetics, the largest ever genomic study of C diff shows how bacteria can evolve.

The research indicates C diff is continuing to evolve in response to human behaviour.

It could help inform patient diet and infection control in hospitals.

Dr Nitin Kumar, joint first author from the Wellcome Sanger Institute, said: “Our large-scale genetic analysis allowed us to discover that C diff is forming a new species.

“This emerging species has existed for thousands of years, but this is the first time anyone has studied C diff genomes in this way to identify it.”

Dating analysis revealed that C diff Clade A first appeared about 76,000 years ago.

But the number of different strains started to increase at the end of the 16th Century, before the founding of modern hospitals.

This group has since thrived and evolved in hospital settings.