Catch me if you conjugate. Plasmid recovery from complex ecosystems using secreted pilus machinery as a hook.

Microbes engage in promiscuous but very permissive sex allowing them to acquire new competences from their neighbors such as antibiotic resistance via by many pathogens from environmental microbes. Plasmid conjugation, notably, involves the secretion of a filamentlike appendage – the conjugative pilus – that brings bacterial cells into contact and funnels plasmid DNA transfer. Yet, we do not know much about the true diversity of conjugative plasmids in Nature and very little on their transfer dynamics, despite their proven involvement in bacterial adaptation. Current assays of plasmid transfer are limited by our inability to grow most environmental microbes and the relatively low abundance of plasmids relative to total environmental DNA. Here I propose a method to directly target the protein transfer mechanisms and recover cells hosting a conjugative plasmid. This holistic approach will be applied on complex hot-spots of plasmid transfers environmental samples, such as wastewaters. I expect here not only to uncover novel plasmids but also their dynamic in-situ. The expected results project are of the utmost importance since the dissemination of antibiotic resistance in many critical pathogens is mainly driven by plasmids but hosts responsible for their dissemination in the environment are unknown.