title: Phenotypic variation and host interactions of Xenorhabdus bovienii SS-2004, the entomopathogenic symbiont of Steinernema jollieti nematodes.
abstract: Xenorhabdus bovienii (SS-2004) bacteria reside in the intestine of the infective-juvenile (IJ) stage of the entomopathogenic nematode, Steinernema jollieti. The recent sequencing of the X. bovienii genome facilitates its use as a model to understand host - symbiont interactions. To provide a biological foundation for such studies, we characterized X. bovienii in vitro and host interaction phenotypes. Within the nematode host X. bovienii was contained within a membrane bound envelope that also enclosed the nematode-derived intravesicular structure. Steinernema jollieti nematodes cultivated on mixed lawns of X. bovienii expressing green or DsRed fluorescent proteins were predominantly colonized by one or the other strain, suggesting the colonizing population is founded by a few cells. Xenorhabdus bovienii exhibits phenotypic variation between orange-pigmented primary form and cream-pigmented secondary form. Each form can colonize IJ nematodes when cultured in vitro on agar. However, IJs did not develop or emerge from Galleria mellonella insects infected with secondary form. Unlike primary-form infected insects that were soft and flexible, secondary-form infected insects retained a rigid exoskeleton structure. Xenorhabdus bovienii primary and secondary form isolates are virulent towards Manduca sexta and several other insects. However, primary form stocks present attenuated virulence, suggesting that X. bovienii, like Xenorhabdus nematophila may undergo virulence modulation.
authors.affiliation: Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA.
authors.forename: Darby R
authors.initials: DR
authors.lastname: Sugar
authors.forename: Kristen E
authors.initials: KE
authors.lastname: Murfin
authors.forename: John M
authors.initials: JM
authors.lastname: Chaston
authors.forename: Aaron W
authors.initials: AW
authors.lastname: Andersen
authors.forename: Gregory R
authors.initials: GR
authors.lastname: Richards
authors.forename: Limaris
authors.initials: L
authors.lastname: deLéon
authors.forename: James A
authors.initials: JA
authors.lastname: Baum
authors.forename: William P
authors.initials: WP
authors.lastname: Clinton
authors.forename: Steven
authors.initials: S
authors.lastname: Forst
authors.forename: Barry S
authors.initials: BS
authors.lastname: Goldman
authors.forename: Karina C
authors.initials: KC
authors.lastname: Krasomil-Osterfeld
authors.forename: Steven
authors.initials: S
authors.lastname: Slater
authors.forename: S Patricia
authors.initials: SP
authors.lastname: Stock
authors.forename: Heidi
authors.initials: H
authors.lastname: Goodrich-Blair
mesh_terms: D000293:Adolescent; D000818:Animals; D054884:Host-Pathogen Interactions; D006801:Humans; D007422:Intestines / Q000382:microbiology; D010641:Phenotype; D017168:Rhabditida / Q000382:microbiology* / Q000502:physiology; D013559:Symbiosis; D014774:Virulence / Q000502:physiology; D020593:Xenorhabdus / Q000145:classification* / Q000502:physiology