title: Transcriptomic Analysis of Yersinia enterocolitica Biovar 1B Infecting Murine Macrophages Reveals New Mechanisms of Extracellular and Intracellular Survival.
abstract: Yersinia enterocolitica is typically considered an extracellular pathogen; however, during the course of an infection, a significant number of bacteria are stably maintained within host cell vacuoles. Little is known about this population and the role it plays during an infection. To address this question and to elucidate the spatially and temporally dynamic gene expression patterns of Y. enterocolitica biovar 1B through the course of an in vitro infection, transcriptome sequencing and differential gene expression analysis of bacteria infecting murine macrophage cells were performed under four distinct conditions. Bacteria were first grown in a nutrient-rich medium at 26 °C to establish a baseline of gene expression that is unrelated to infection. The transcriptomes of these bacteria were then compared to bacteria grown in a conditioned cell culture medium at 37 °C to identify genes that were differentially expressed in response to the increased temperature and medium but not in response to host cells. Infections were then performed, and the transcriptomes of bacteria found on the extracellular surface and intracellular compartments were analyzed individually. The upregulated genes revealed potential roles for a variety of systems in promoting intracellular virulence, including the Ysa type III secretion system, the Yts2 type II secretion system, and the Tad pilus. It was further determined that mutants of each of these systems had decreased virulence while infecting macrophages. Overall, these results reveal the complete set of genes expressed by Y. enterocolitica in response to infection and provide the groundwork for future virulence studies.
authors.affiliation: Department of Systems Biology, Sandia National Laboratories, Livermore, California, USA zachwbent@gmail.com rmeaghe@sandia.gov.
authors.forename: Zachary W
authors.initials: ZW
authors.lastname: Bent
authors.affiliation: Department of Systems Biology, Sandia National Laboratories, Livermore, California, USA.
authors.forename: Kunal
authors.initials: K
authors.lastname: Poorey
authors.affiliation: Department of Systems Biology, Sandia National Laboratories, Livermore, California, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Brazel
authors.affiliation: Department of Biotechnology and Bioengineering, Sandia National Laboratories, Livermore, California, USA.
authors.forename: Annette E
authors.initials: AE
authors.lastname: LaBauve
authors.affiliation: Department of Systems Biology, Sandia National Laboratories, Livermore, California, USA.
authors.forename: Anupama
authors.initials: A
authors.lastname: Sinha
authors.affiliation: Department of Systems Biology, Sandia National Laboratories, Livermore, California, USA.
authors.forename: Deanna J
authors.initials: DJ
authors.lastname: Curtis
authors.affiliation: Department of Systems Biology, Sandia National Laboratories, Livermore, California, USA.
authors.forename: Samantha E
authors.initials: SE
authors.lastname: House
authors.affiliation: Department of Systems Biology, Sandia National Laboratories, Livermore, California, USA.
authors.forename: Karen E
authors.initials: KE
authors.lastname: Tew
authors.affiliation: Department of Systems Biology, Sandia National Laboratories, Livermore, California, USA.
authors.forename: Rachelle Y
authors.initials: RY
authors.lastname: Hamblin
authors.affiliation: Department of Systems Biology, Sandia National Laboratories, Livermore, California, USA.
authors.forename: Kelly P
authors.initials: KP
authors.lastname: Williams
authors.affiliation: Department of Biotechnology and Bioengineering, Sandia National Laboratories, Livermore, California, USA.
authors.forename: Steven S
authors.initials: SS
authors.lastname: Branda
authors.affiliation: Department of Food Science and Technology, University of California, Davis, California, USA.
authors.forename: Glenn M
authors.initials: GM
authors.lastname: Young
authors.affiliation: Department of Biotechnology and Bioengineering, Sandia National Laboratories, Livermore, California, USA zachwbent@gmail.com rmeaghe@sandia.gov.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Meagher
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D020869:Gene Expression Profiling; D055786:Gene Knockout Techniques; D008264:Macrophages / Q000382:microbiology*; D051379:Mice; D050296:Microbial Viability; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism; D015008:Yersinia enterocolitica / Q000235:genetics* / Q000254:growth & development*
chemical_list: D037521:Virulence Factors