Psl-Dependent Cooperation Contributes to Drug Resistance of Pseudomonas aeruginosa in Dual-Species Biofilms with Acinetobacter baumannii

Co-infection of Pscudomonas acruginosa (Pa) and Acinetobacter baumannii (Ab) 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 Pa and Ab dual-species biolilm 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 Pa, Psl exopolysaccharide in particular, promoted its interactions with Ab against imipenem stress. We further found other EPS structural liber-eDNA contributed to the Psl-dependent dual-species biofilm stability under antibiotic treatment. Thus, targeting the EPS structural fibers such as Psi and extracellular DNA (eDNA) is a potent strategy for controlling polymicrobial biofilm related infections.

Automated summary

The co-infection of Pseudomonas aeruginosa (Pa) and Acinetobacter baumannii (Ab) in ICU patients is common but challenging to eliminate. Research suggests that antibiotic exposure reshapes the community compositions of dual-species biofilms, with different EPS structures playing roles in maintaining stability, highlighting the potential of targeting EPS structural fibers like Psi and extracellular DNA (eDNA) as a strategy for controlling polymicrobial biofilm-related infections.