New and highly infectious E. coli strain resistant to powerful antibiotics

A new type of E. coli that is both highly infectious and resistant to some antibiotics has been discovered.

The newly identified mutation of antibiotic-resistant E. coli is described in a new paper published in Nature Communications. The team, including Professor Alan McNally from the University of Birmingham suggests that some existing antibiotics called carbapenems will be ineffective against the bacteria.

While scientists have already identified strains of carbapenem-resistant Escherichia coli (CREC) and note that is one of the most problematic AMR bacteria in circulation, with the ST410 version becoming the most common resistant E. coli in Chinese hospitals between 2017 and 2021. Now, the discovery of a stronger and more infectious version of ST410 CREC, called B5/H24RxC, has been implicated in two outbreaks in a children's hospital in China.

Analysis of the B5/H24RxC strain in a lab showed the bacteria was able to grow faster and was more harmful to living organisms than previous versions.

Professor Alan McNally, Director of Institute of Microbiology and Infection at the University of Birmingham and an author of the study said, "It has often been thought that the E. coli that evolve to be most resistant to antibiotics do so at the cost of being able to cause infections in humans. Our incredibly important collaboration with our partners in China ... has allowed us to discover and characterize this new clone of E. coli which is becoming both more antimicrobial resistant and more pathogenic.

"This is a worrying new trend and we would now urge surveillance labs across the world to be on the look out for this new clone which we know has spread beyond China."

Urgent need for collaborative effort

Samples from hospitals across 26 Chinese provinces between 2017 and 2021 were used to examine how widespread antibiotic-resistant E. coli was.

Using a total of 388 CREC isolates from various clinical samples including urine, sputum and blood, the team were able to identify that ST410 was the most common CREC, and given that the highest proportion of samples (111) were taken from urine, that there may be a connection to urinary tract infections.

Dr. Ibrahim Xiaoling Ba, Senior Research Associate in the Department of Veterinary Medicine at the University of Cambridge, and first author of the paper said, "Our study highlights the evolving landscape of antimicrobial resistance within clinically significant pathogens, such as E. coli, emphasizing the urgent need for collaborative efforts to address and mitigate this escalating challenge in global public health."