Understanding zoonotic antibiotic resistance in E. coli – a collaborative project

OUCRU researchers are proud to be involved in HECTOR – an interdisciplinary, multi-national research consortium which is investigating the genetic factors that contribute to antibiotic resistance.

Dr Ngo Thi Hoa, the leader of this collaboration in Vietnam and Oxford says: “The use of antibiotics in agriculture contributes substantially to the development of antibiotic resistant bacteria; particularly in E. coli ­- a type of bacteria that exists normally in humans and animals, but can sometimes cause opportunistic infections. However, we don’t fully understand how frequently bacteria and/or antibiotic resistance genes are transmitted between animals and humans. Results of this collaborative project will shed light on whether genetic factors of E. coli could be associated with their colonisation and spread between animals and humans. It will also tell us about how commonly the bacteria we study are carrying antibiotic resistance genes.”

Antibiotics have revolutionized medicine and saved countless lives. Their discovery represented a quantum leap in the treatment of infectious diseases. Sadly, many bacteria are now resistant to multiple antibiotics, to the extent that resistant strains have become a major public health threat. There is a rising fear that bacterial infections might even become untreatable in the future. Many different factors have contributed to this situation including horizontal resistance gene transfer within and between bacteria species.

An example of how antibiotic resistant bacteria can spread between animals and humans can be found in the case of the antibiotic drug colisitin. Discovered roughly 70 years ago, doctors stopped using colistin in human medicine because it can be highly toxic, but it is still used in veterinary medicine, mostly for treating intestinal infections. Nowadays, in the wake of increasing numbers of severe human infections caused by multidrug-resistant Gram-negative bacteria, colistin has become a key last resort drug. Recently, a plasmid-encoded colistin resistance gene was isolated from an animal-associated E. coli strain, and subsequently found worldwide on multi-resistance plasmids from bacteria isolated from humans, animals, retail meat and environmental samples. This indicated that even colistin, a last-resort antibiotic, is now under threat.

The HECTOR consortium will be looking specifically at many E. coli isolates from human, animal and environmental sources in Europe and Vietnam. They will look at genetic factors in the isolates that might contribute to the ability of the E. coli to live in a specific host or environment. The consortium will also look at how antibiotic resistant genes are spread in E. coli. Then, they will use that data to set up a mathematical model that can predict the preferred host for the bacteria (e.g., pigs, chickens, humans etc.) and predict how these antibiotic resistance genes might be transmitted. This model will enable scientists to develop risk assessments on transmission of bacteria between animals and humans and to design and set up targeted interventions to prevent and reduce such transmission in the future.

The HECTOR consortium brings together seven academic and public health research groups from Germany, The Netherlands, Spain, the United Kingdom and Vietnam from the fields of human and veterinary medicine, basic science and bioinformatics. HECTOR stands for Host restriction of Escherichia Coli on Transmission dynamics and spread Of antimicrobial Resistance. The HECTOR consortium has received funding for three years from the Joint Programming Initiative on Antimicrobial Resistance (JPIAMR)  to undertake this work.