title: Role for the Burkholderia pseudomallei type three secretion system cluster 1 bpscN gene in virulence.
abstract: Burkholderia pseudomallei, the causal agent of melioidosis, employs a number of virulence factors during its infection of mammalian cells. One such factor is the type three secretion system (TTSS), which is proposed to mediate the transport and secretion of bacterial effector molecules directly into host cells. The B. pseudomallei genome contains three TTSS gene clusters (designated TTSS1, TTSS2, and TTSS3). Previous research has indicated that neither TTSS1 nor TTSS2 is involved in B. pseudomallei virulence in a hamster infection model. We have characterized a B. pseudomallei mutant lacking expression of the predicted TTSS1 ATPase encoded by bpscN. This mutant was significantly attenuated for virulence in a respiratory melioidosis mouse model of infection. In addition, analyses in vitro showed diminished survival and replication in RAW264.7 cells and an increased level of colocalization with the autophagy marker protein LC3 but an unhindered ability to escape from phagosomes. Taken together, these data provide evidence that the TTSS1 bpscN gene product plays an important role in the intracellular survival of B. pseudomallei and the pathogenesis of murine infection.
authors.affiliation: Department of Biochemistry and Molecular Biology, Monash University, Clayton Campus, VIC 3800, Australia.
authors.forename: Tanya
authors.initials: T
authors.lastname: D'Cruze
authors.forename: Lan
authors.initials: L
authors.lastname: Gong
authors.forename: Puthayalai
authors.initials: P
authors.lastname: Treerat
authors.forename: Georg
authors.initials: G
authors.lastname: Ramm
authors.forename: John D
authors.initials: JD
authors.lastname: Boyce
authors.forename: Mark
authors.initials: M
authors.lastname: Prescott
authors.forename: Ben
authors.initials: B
authors.lastname: Adler
authors.forename: Rodney J
authors.initials: RJ
authors.lastname: Devenish
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D058947:Bacterial Secretion Systems / Q000235:genetics*; D016957:Burkholderia pseudomallei / Q000235:genetics* / Q000472:pathogenicity*; D008554:Melioidosis / Q000382:microbiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D046529:Microscopy, Electron, Transmission; D005810:Multigene Family; D010588:Phagosomes; D017384:Sequence Deletion; D037521:Virulence Factors / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D058947:Bacterial Secretion Systems; D037521:Virulence Factors