A groundbreaking new study has led to the creation of the most detailed bacterial evolutionary map to date, offering hope for the future of treating antibiotic-resistant infections especially those caused by Escherichia coli (E. coli), such as urinary tract infections. This innovative resource could pave the way for highly targeted precision medicine approaches, allowing scientists to move away from broad-spectrum antibiotics and toward more refined, individualized therapies.

Conducted by researchers at the Wellcome Sanger Institute, the University of Oslo, UiT The Arctic University of Norway, and other collaborators, the study utilizes large-scale, long-read DNA sequencing to explore plasmids circular pieces of genetic material capable of transferring traits like antibiotic resistance between bacteria. Focusing on E. coli, one of the most commonly studied microbes, the research team was able to construct 4,485 complete plasmid genomes from more than 2,000 bloodstream infection samples collected over a 16-year period in Norway.

What sets this study apart is its ability to trace the horizontal gene transfer and evolutionary history of these plasmids across 216 different E. coli strains, including the four most dominant strains circulating in the UK today. By using a two-dimensional mapping approach, the researchers revealed how plasmids have co-evolved with E. coli over the past 300 years, giving insight into the mechanisms that drive bacterial adaptation and spread especially the traits that make certain strains more infectious or drug-resistant.

One of the most exciting findings is the discovery of a plasmid that allows certain E. coli strains to produce bacteriocins substances that kill closely related bacterial strains. Notably, strains carrying these bacteriocins were found to effectively eliminate even the most drug-resistant strains, offering a promising alternative to traditional antibiotics. Intriguingly, the research also found that the ability to produce bacteriocins and multidrug resistance rarely coexist in the same strain, suggesting a potential strategy for managing harmful bacterial populations by encouraging competition.

This research underscores how bacteria don’t just evolve in opposition to human interventions like antibiotics; they’re also constantly adapting to outcompete each other within environments like the human gut. While most E. coli strains are harmless, others can become dangerous if they enter the bloodstream, especially in individuals with weakened immune systems. Understanding how these strains evolve and what genetic tools they use can help scientists predict outbreaks, understand resistance patterns, and ultimately develop targeted treatments.

The implications of this study are vast. By identifying and tracking specific plasmids and the genetic traits they confer, researchers now have a roadmap for developing precision treatments that target bacterial infections at their root cause. Rather than using one-size-fits-all antibiotics, future treatments could zero in on the exact genetic makeup of an infection, preserving the body’s beneficial microbes while neutralizing harmful ones.

Moreover, this high-resolution plasmid map serves as a crucial resource for the global scientific community. It not only aids in understanding the biology and evolution of E. coli but also sets the stage for novel approaches to combating antibiotic resistance. With further research, this tool could be used to foresee and prevent bacterial outbreaks or even introduce less harmful strains to outcompete more dangerous ones in the human microbiome.

In short, this evolutionary map doesn’t just illuminate the past it’s a guiding light for the future of precision medicine in infectious disease.

Source: https://www.sanger.ac.uk/news_item/precision-medicine-could-be-possible-in-the-fight-against-antibiotic-resistance/