A new instrument that has the potential to help minimize the spread of antimicrobial resistance is revealing early potential by using a bacterial immune system as a gene-editing tool.
As per the World Health Organization, antimicrobial resistance is a main global risk, as it has around five million deaths every year caused due to antibiotics failing to cure infections.
Often, bacteria build resistance when resistant genes are transported among hosts. One method that this happens is through plasmids—DNA circular strands—which can spread seamlessly among bacteria and quickly replicate. This can happen in human bodies and environmental conditions, like waterways.
The CRISPR-Cas gene editing system was harnessed by the Exeter team, which can target particular DNA sequences and cuts through them when they are witnessed. The scientists engineered a plasmid that can particularly target the resistance gene for Gentamicin—which is a commonly used antibiotic.
The new study was published in Microbiology. It discovered that, in lab experiments, the plasmid safeguarded its host cell from building resistance. In addition, scientists discovered that the plasmid efficiently targeted antimicrobial-resistant genes in hosts to which it transported, drawing back their resistance.
Antimicrobial resistance threatens to outstrip covid in terms of the number of global deaths. We urgently need new ways to stop resistance spreading between hosts. Our technology is showing early promise to eliminate resistance in a wide range of different bacteria. Our next step is to conduct experiments in more complex microbial communities. We hope one day it could be a way to reduce the spread of antimicrobial resistance in environments such as sewage treatment plants, which we know are breeding grounds for resistance.”
David Walker-Sünderhauf, Study Lead Author, University of Exeter
Sünderhauf, D. W., et al. (2023). Removal of AMR plasmids using a mobile, broad host-range CRISPR-Cas9 delivery tool. Microbiology. doi.org/10.1099/mic.0.001334