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, IN SOO - Hannam University
  Submitted to: Meeting Abstract
                                    Publication Type: Abstract Only
                                    Publication Acceptance Date: 4/13/2011
                                    Publication  Date: 4/13/2011
                                    Citation: Bearson, S.M., Bearson, B.L., Lee, I. 2011. A mutation in the pnp gene encoding polynucleotide phosphorylase attenuates virulence of Salmonella enterica serovar typhimurium in swine [abstract]. 111th General Meeting American Society for Microbiology. p.1487.Interpretive Summary:
                                Technical Abstract: Background: The pnp gene encodes polynucleotide phosphorylase, an exoribonuclease involved in RNA degradation. A mutation in the pnp gene was previously identified by our group in a signature-tagged mutagenesis screen designed to search for Salmonella enterica serovar Typhimurium genes required for survival in an ex vivo swine stomach content assay. The current study evaluated the attenuation and colonization potential of the S. Typhimurium pnp mutant in the porcine host. Methods: Eight-week old pigs were intranasally inoculated with 109 cfu of either the 4232 S. Typhimurium parent strain or the pnp mutant (n=5/group). Over a 7-day study, rectal temperatures (fever) evaluated clinical signs of infection, while quantitative and qualitative bacteriological evaluation of fecal and tissue samples measured the level of Salmonella shedding and tissue colonization in the inoculated pigs. Results: An increase in the average rectal temperature (fever) was observed for the pigs inoculated with wild-type S. Typhimurium, whereas inoculation with the pnp mutant did not result in a significant increase in the average body temperature. Fecal shedding of the pnp mutant was significantly reduced during the 7-day study compared to the wild-type strain. Tissue colonization was also dramatically reduced in the pigs inoculated with the pnp mutant compared to the parental strain, including the tonsils, ileocecal lymph nodes, Peyer’s Patch region of the ileum, cecum and contents of the cecum. Conclusions: The pnp gene encoding polynucleotide phosphorylase is required for S. Typhimurium virulence and gastrointestinal colonization of the natural swine host.


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