U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Food Safety and Enteric Pathogens Research: Ames, IA
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    Careers


        


                    Additional ResourcesSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Midwest Area Ames, Iowa National Animal Disease Center Food Safety and Enteric Pathogens Research Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications

Title:   Author  item
                                            Bearson, Shawnitem
                                            Bearson, Bradley

                                                         - *Brad*item
                                            LEE, INSOO - HANNAM UNIV, KOREA
  Submitted to: Meeting Abstract
                                    Publication Type: Abstract Only
                                    Publication Acceptance Date: 2/20/2009
                                    Publication  Date: 5/20/2009
                                    Citation: Bearson, S.M., Bearson, B.L., Lee, I. 2009. The Poxr Gene of Salmonella Enterica Serovar Typhimurium is Involved in Stress Survival and Swine Colonization [abstract].  American Society for Microbiology Meeting. p. 619.Interpretive Summary:
                                Technical Abstract: Mutations in the poxR gene (STM4344; yjeA; poxA) of Salmonella enterica serovar Typhimurium  (S. Typhimurium) have previously been shown to cause several phenotypic alterations including reduced pyruvate oxidase activity, virulence attenuation in the mouse model, and enhanced sensitivity to various bacterial growth inhibitors such as antibiotics, dyes and the antimicrobial peptide protamine.  Our research group identified a mutation in the poxR gene during a S. Typhimurium signature-tagged mutagenesis screen to identify genes important for survival in the harsh environment of the swine stomach, a first line of defense against foodborne pathogens.  Not only was the poxR mutant ~20-fold more sensitive in the ex vivo swine stomach content assay than the parental strain, but the poxR mutant was also more sensitive to pH 3.0 acidic challenge.  To determine if the mutation in poxR affects colonization of the swine gastrointestinal tract, eight week old pigs were intranasally inoculated with either the chi4232 S. Typhimurium parent strain or the poxR mutant (n = 5 for each group).  Fecal shedding of the poxR mutant was significantly reduced during the 7-day study compared to the wild-type strain at 1, 2, 3, 5 and 7 days post-inoculation (dpi), as was the presence of the mutant in the cecal contents of the pigs and colonization of the cecal tissue at 7 dpi (p < 0.05).  Colonization of the Peyer’s Patch region of the ileum trended towards significance with a p-value = 0.075, but colonization of the ileocecal lymph nodes was identical for swine inoculated with the mutant versus the wild-type strain.  As a predicted lysyl-tRNA synthetase, reduction in PoxR levels could alter which mRNA transcripts are translated, thereby changing the protein profile of the pathogen and affecting a variety of bacterial processes including stress survival and host colonization.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov