Rifaximin prophylaxis causes resistance to the last-resort antibiotic daptomycin

The study reveals that rifaximin, an antibiotic used to prevent liver disease, causes cross-resistance to daptomycin in vancomycin-resistant Enterococcus faecium (VREfm). This resistance is caused by amino acid changes in the bacterial RNA polymerase, leading to cell membrane remodeling and reduced antibiotic binding. This resistance is widespread globally, compromising the clinical use of daptomycin, a crucial last-resort intervention for multidrug-resistant pathogens.