Interaction between Staphylococcus aureus and Pseudomonas aeruginosa is beneficial for colonisation and pathogenicity in a mixed biofilm

Abstract Debate regarding the co-existence of Staphylococcus aureus and Pseudomonas aeruginosa in wounds remains contentious, with the dominant hypothesis describing a situation akin to niche partitioning, whereby both microorganisms are present but occupy distinct regions of the wound without interacting. In contrast, we hypothesised that these microorganisms do interact during early co-colonisation in a manner beneficial to both bacteria. We assessed competitive interaction between S. aureus and P. aeruginosa in biofilm cultured for 24–72 h and bacterial aggregates analogous to those observed in early (