Interspecies interactions induce exploratory motility in <i>Pseudomonas aeruginosa</i>.

Abstract

Microbes often live in multispecies communities where interactions among community members impact both the individual constituents and the surrounding environment. Here, we developed a system to visualize interspecies behaviors at initial encounters. By imaging two prevalent pathogens known to be coisolated from chronic illnesses, <i>Pseudomonas aeruginosa</i> and <i>Staphylococcus aureus</i>, we observed <i>P. aeruginosa</i> can modify surface motility in response to secreted factors from <i>S. aureus</i>. Upon sensing <i>S. aureus, P. aeruginosa</i> transitioned from collective to single-cell motility with an associated increase in speed and directedness - a behavior we refer to as 'exploratory motility'. Explorer cells moved preferentially towards <i>S. aureus</i> and invaded <i>S. aureus</i> colonies through the action of the type IV pili. These studies reveal previously undescribed motility behaviors and lend insight into how <i>P. aeruginosa</i> senses and responds to other species. Identifying strategies to harness these interactions may open avenues for new antimicrobial strategies.