In a groundbreaking revelation, researchers from the University of Pittsburgh School of Medicine have uncovered that a highly drug-resistant bacterium, particularly prevalent in healthcare settings, has developed a remarkable ability to produce antimicrobials, enabling it to eliminate competing strains.

This evolutionary leap positions this bacterium as the new dominant threat in hospitals, a discovery that could reshape our understanding of developing effective treatments for some of the most dangerous pathogens.

Published in *Nature Microbiology*, this study reveals a significant trend that researchers stumbled upon while sifting through hospital data. Not only is this phenomenon localized, but it also appears to resonate on a global scale, raising alarm bells among health professionals.

Senior author Daria Van Tyne, Ph.D., an associate professor in Pitt's Division of Infectious Diseases, stated, “As we examined the evolution of these pathogens, it became clear that significant changes were occurring. This particular bacterium has become notably challenging to combat.”

The Enhanced Detection System for Health Care-Associated Transmission (EDS-HAT) played a crucial role in this uncovering. EDS-HAT tracks genetic signatures of infections in hospital patients, providing vital data that enables clinicians to intervene promptly when outbreaks occur.

However, it became clear to lead author Emma Mills, a graduate student in microbiology and immunology, that EDS-HAT also holds a wealth of historical information elucidating bacterial evolution.

Focusing her research on vancomycin-resistant Enterococcus faecium (VREfm), which is notorious for evading treatment with the common antibiotic vancomycin, Mills found that the bacterium poses a significant risk, particularly to immunocompromised patients.

Alarmingly, VREfm has a mortality rate of approximately 40% in infected individuals. This is particularly concerning for patients undergoing antibiotic treatment, which can diminish bacterial diversity in their microbiomes and create an environment conducive to drug-resistant bacteria like VREfm.

In her analysis of over 700 VREfm samples collected from hospitalized patients over six years, Mills identified a troubling trend: the variety of strains diminished sharply, from around eight prevalent types in 2017 to just two dominant strains by 2022.

Astonishingly, these two strains were responsible for a staggering four out of five infections.

Diving deeper, Mills discovered these dominant strains had mastered the synthesis of a bacteriocin—an antimicrobial substance they now use to decimate competing VREfm strains.

This newfound offensive capability allows them to monopolize nutrients, facilitating rapid reproduction and further establishing their dominance.

Curiosity drove Mills to investigate whether this trend was mirrored globally.

By examining a public database of more than 15,000 VREfm genomes collected from 2002 to 2022, she confirmed that this alarming evolution of VREfm was not just a local issue; it was indeed a global phenomenon.

“This was a completely unexpected finding,” Mills remarked. “Once these lethal strains land in a hospital, they swiftly outmatch other VRE variants in patients, resulting in a brutal 'kill your buddies' scenario.”

While Van Tyne noted that this discovery may not yield immediate clinical implications, as the new strains do not appear to cause greater harm than their predecessors, it highlights a potential shift in therapeutic strategies.

As VREfm strains continue to narrow in diversity, there is hope that we may develop targeted therapies using either antibiotics or phage therapy, which could significantly alter the landscape of treatment.

Even more intriguing is the prospect of harnessing these bacteriocins for therapeutic use.

“If these mechanisms are so effective in combating their peers, imagine the possibilities if we weaponize them for our own purposes,” Van Tyne suggested.

Stay tuned as we unravel more on this evolving story and its potential to influence modern medicine! Will scientists soon hold the key to taming these insidious superbugs? The battle against superbugs just took a dramatic turn!