Living the fly life: Adaptation and diversification of mosquito-derived Serratia strains

Whether characterized as innocuous isolates from soil and water, causative agents of nosocomial infections, or pathogens in various insect species, strains of the Gram-negative bacterium Serratia marcescens possess a diverse genomic repertoire that contributes to their ubiquity in both natural and built environments. Recently, a novel prodigiosin-producing strain of S. marcescens with a reduced genome was isolated from a locally maintained colony of Culex quinquefasciatus mosquitoes. To elucidate the genetic features that enable Serratia to colonize and/or survive within mosquitoes relative to other common niches this bacterium occupies, a complete genome was generated and analyzed to identify notable genes or gene products unique to (or uniquely missing from) it. These results will inform future efforts that utilize this and similar microorganisms for insect biocontrol and paratransgenic research in important vectors of human disease, and the methodology is currently being used by our lab to analyze other mosquito-derived bacteria.