In situ monitoring of IncF plasmid transfer on semi-solid agar surfaces reveals a limited invasion of plasmids in recipient colonies

摘要: Most natural conjugative IncF plasmids encode a fertility inhibition system that represses transfer gene expression in the majority of plasmid-carrying cells. The successful spread these clinically relevant bacteria has been suggested to be supported by transitory derepression newly formed transconjugants. In this study, we aimed monitor extent during agar surface matings situ comparing plasmid R1 and its derepressed mutant R1drd19 at low initial cell densities. A zygotic induction strategy was used visualize spatial distribution fluorescent transconjugants within heterogeneous environment. Epifluorescence confocal microscopy revealed different patterns for both plasmids, however, beyond first five recipient layers adjacent donor cells not observed. Similar results were observed other prototypical plasmids. These cannot rule out contributes limited invasion, but factors like nutrient availability or structure seem limit spread.