Drug-resistant bacteria evolve to dominate healthcare settings

Scientists have discovered that a type of drug-resistant bacteria has evolved to dominate healthcare environments by using an antimicrobial tool against its rivals. These findings were made by researchers at the University of Pittsburgh School of Medicine. They examined data from local hospitals and confirmed that this evolution is also happening globally. The study was published in Nature Microbiology and may influence how new treatments are developed for dangerous bacteria. The researchers used a system called Enhanced Detection System for Healthcare-Associated Transmission (EDS-HAT). This system analyzes genetic information from infections and helps doctors stop potential outbreaks quickly. Lead researcher Emma Mills focused on vancomycin-resistant Enterococcus faecium (VREfm), a bacteria that is deadly for about 40% of those it infects. It particularly affects hospitalized and immunocompromised patients. By analyzing infection samples collected over six years, Mills found that the number of VREfm strains decreased dramatically, leaving only two dominant strains by the end of 2022. These dominant strains gained the ability to produce bacteriocins, which are substances that can kill other bacteria. This allowed them to outcompete other strains and thrive. Mills later checked a global database and confirmed that this pattern was occurring worldwide. While these findings do not immediately change clinical practice, they hint at new ways to create treatments. The narrowing diversity of VREfm suggests that therapies could be developed to target fewer types of the bacteria. There is also potential to use bacteriocins as a treatment method.