Psl-Dependent Cooperation Contributes to Drug Resistance of in Dual-Species Biofilms with .

Co-infection of () and () is frequently observed in intensive care unit (ICU) patients but difficult to eliminate. Current clinical practice based on microbial population characterization and single-species-based antibiotic resistance profiling has ignored the potential interspecies interactions, which might lead to novel drug-resistance phenotypes. Here, we investigated the impacts of interspecies interactions on antibiotic therapies by establishing a and dual-species biofilm model. Our data showed that antibiotic exposure would reshape the community compositions of dual-species biofilms, and those of the extracellular polymeric substance (EPS) matrix of , Psl exopolysaccharide in particular, promoted its interactions with against imipenem stress. We further found other EPS structural fiber-eDNA contributed to the Psl-dependent dual-species biofilm stability under antibiotic treatment. Thus, targeting the EPS structural fibers such as Psl and extracellular DNA (eDNA) is a potent strategy for controlling polymicrobial biofilm related infections.