Most cases of E. coli infections are mild, but some strains can cause severe symptoms and even life-threatening complications. More severe infections are usually treated with antibiotics but the rise in multidrug resistance strains of E.coli is concerning. Multidrug-resistant strains are resistant to many different types of antibiotics, making them very difficult to treat.
Previous work shows that multi-drug resistance alone is not sufficient to drive strains to complete dominance. This most recent study demonstrates that regardless of multi-drug resistant status, certain types of E.coli will outcompete others to live in the human gut.
The work was completed in parts. First, both multi-drug resistant and non-resistant gut-dwelling E.coli were found to easily colonise a mammalian gut. In a second part of the study, the multi-drug resistant strain was found to efficiently displace an already established gut-dwelling E.coli from the mouse intestinal tract. The study provided further details to demonstrate that multidrug resistant lineages of extraintestinal E.coli have particular genetic differences that appear to give them a competitive advantage.
Successful strains of E.coli need to be able to spread between individuals or from the environment into individual hosts. The new study demonstrates that a particular strain, known as MDR ST131, can readily colonise new hosts, even if those hosts are already have E.coli in their healthy gut.
E.coli are bacteria commonly found in the environment, foods and intestines of people and animals. There are many different types of E. coli. Although most strains of E. coli are harmless, others can cause illness, including diarrhoea, urinary tract infections, and often-fatal blood stream infections.
