Monitoring genes for antimicrobial resistance

Australian researchers are offering a new perspective on antimicrobial resistance (AMR) that they hope will lead to the phenomenon being characterised as an ecological disease — one which can be defined, tested and monitored in a different way.

AMR occurs when microorganisms such as bacteria, viruses, parasites and fungi develop resistance against medicines that were previously able to cure them. According to Dr Carolyn Michael, Dr Maurizio Labbate and Dr Ashley Franks, not enough focus has been given to the problem of rapidly and accurately monitoring the root cause of the AMR crisis. Their theory has been published in the journal Open Biology.

“Monitoring the crisis is largely limited to counting increasing numbers of resistant pathogens,” said Dr Michael, from the University of Technology Sydney (UTS). “Rather than monitoring pathogens, we are proposing monitoring resistance genes that exist throughout the microbial world and not just in pathogens. Doing this will let us see rising numbers of resistance genes before they get to a pathogen and also keep an eye on the different types of resistance genes already in pathogens.”

The research team proposes tracking resistance gene frequency across the environment so that the early phases of the rise of resistance genes are detected and managed. This would involve not only monitoring microbial DNA in hospital settings, but also sampling in surrounding environments, such as shopping precincts, transport hubs and even sewage treatment facilities.

Together with rigorous stewardship of existing antimicrobials, this protocol would mean that the effectiveness of current and future antimicrobials would be preserved. Measuring increases in resistance gene numbers would give clinicians and health authorities the information they need to recommend which antimicrobials should be used and which must be ‘rested’.

The researchers also address the critical issue of limiting resistance gene and antimicrobial stressor flow to the environment by advocating high-level precautions typical of quarantine wards, sterilisation of effluent and, when necessary, the complete withdrawal of certain antibiotics with high levels of resistance genes. As explained by Dr Labbate, also from UTS, “This approach can be used to monitor AMR across all environments and, if applied, will also help us understand the links between these environments that are contributing to AMR.”

“I’ve spent a lot of time in clinical settings and I know doctors are frustrated that they have no way of knowing how long the antimicrobials that they rely on to cure their patients will continue to work,” Dr Michael noted. “Global health authorities also need a way to see if their attempts to reduce AMR are working before a newly untreatable disease strikes. What we are proposing is a global protocol that both defines and measures the size of the problem and so offers solutions to handle this critical issue.”