E. coli strain close to complete resistance

An international study, led by The University of Queensland (UQ), has been tracking a multidrug-resistant E. coli strain that is only one gene away from being resistant to almost all antibiotics. The research has been published in the Proceedings of the National Academy of Sciences USA.

E. coli sequence type 131 (ST131) is a globally disseminated multidrug-resistant clone associated with human urinary tract and bloodstream infections. According to Dr Nouri Ben Zakour of the Australian Infectious Diseases Research Centre, the emergence and spread of the strain could mean that such infections will become more common and difficult to treat.

“More than 150 million cases of urinary tract infection are reported globally every year, so an E. coli resistant to all currently effective antibiotic treatments could be devastating to the community,” she said.

The E. coli ST131 superbug.

Funded by a grant from the National Health and Medical Research Council (NHMRC), the researchers said they used “genome sequencing to examine the molecular epidemiology of a collection of E. coli ST131 strains isolated from six distinct geographical locations across the world spanning 2000-2011”.

“We show that E. coli ST131 strains are distinct from other extraintestinal pathogenic E. coli and arose from a single progenitor strain prior to the year 2000,” they said.

According to Dr Ben Zakour, the pathogen has evolved over this time “from obscurity to notoriety”. Senior researcher Dr Scott Beatson said E. coli ST131 is now “only one gene away from being resistant to all antibiotics that can be used to effectively treat urinary tract infections”, and there are few new antimicrobial drugs in the developmental pipeline.

The study will thus help the researchers to better understand E. coli ST131, with co-first author Dr Nicola Petty, who now leads a research group in the ithree institute at the University of Technology, Sydney, saying it will enable the development of tests to rapidly detect and help combat the spread of the superbug.

Research group leaders Dr Beatson and Professor Mark Schembri were awarded an additional four-year $793,000 grant in the latest NHMRC funding round to continue work in the area