Clostridioides difficile is a virulent pathogen known to be susceptible to vancomycin, although less is known about how microbial interactions might influence the effectiveness of antibiotics. Here we test how the susceptibility of C. difficile to vancomycin is affected when in co-culture with Vancomycin-resistant Enterococcus faecium (VRE). We show that the in vitro co-culture of C. difficile with VRE reduces C. difficile’s susceptibility to vancomycin. In Brain Heart Infusion (BHI) media, susceptibility is reduced compared to Sporulation Media (SM), suggesting different environments affect antibiotic effectiveness. These findings contribute to our understanding of how microbial interactions and the environment affects antibiotic effectiveness.
