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
 Virus and Prion Research: Ames, IA
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    CareersSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Midwest Area Ames, Iowa National Animal Disease Center Virus and Prion 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
                                            Brockmeier, Susanitem
                                            Loving, Crystalitem
                                            Mullins, Michaelitem
                                            Register, Karenitem
                                            Nicholson, Tracyitem
                                            WISEMAN, BARRY - Fios Therapeutics, Incitem
                                            BAKER, RODNEY - Iowa State Universityitem
                                            Kehrli Jr, Marcus
  Submitted to: Clinical and Vaccine Immunology
                                    Publication Type: Peer Reviewed Journal
                                    Publication Acceptance Date: 7/18/2013
                                    Publication  Date: 9/1/2013
                                    Publication URL: https://handle.nal.usda.gov/10113/61365Citation: Brockmeier, S.L., Loving, C.L., Mullins, M., Register, K.B., Nicholson, T.L., Wiseman, B.S., Baker, R.B., Kehrli, Jr., M.E. 2013. Virulence, transmission, and heterologous protection of four isolates of Haemophilus parasuis. Clinical and Vaccine Immunology. 20(9):1466-1472.Interpretive Summary: Haemophilus parasuis is a bacterium that causes Glässer's disease in swine, a disease characterized by chronic debilitation and often death that costs the swine industry millions in losses annually. However, not all strains of the bacterium cause disease. To date, little is known about genetic differences among H. parasuis strains and genetic factors that contribute to its ability to cause disease. Also, current vaccines made against one strain often don't protect against other strains. The goal of this study was to directly compare four isolates of the bacterium for their ability to cause disease in pigs. Three of the isolates caused disease in the pigs, while pigs given the fourth isolate remained healthy. Pigs that were vaccinated with the isolate that did not cause disease were subsequently protected from disease when exposed to one of the disease causing isolates. Thus, strains of H. parasuis that don't cause disease can be used as a vaccine to protect pigs against disease causing strains, and DNA sequencing can now be used to compare the genomes of the different isolates for identification of genes contributing to the ability of H. parasuis to cause disease. These results can be used by swine producers to control losses from this disease and identify whether strains of H. parasuis circulating on the farm are capable of causing disease.
                                Technical Abstract: Haemophilus parasuis causes Glässer's disease, a syndrome of polyserositis, meningitis, and arthritis in swine. Previous studies with H. parasuis have revealed virulence disparity among isolates and inconsistent heterologous protection. In this study, virulence, direct transmission, and heterologous protection of 4 isolates of H. parasuis (SW114, 12939, MN-H, or 29755) were evaluated using a highly susceptible pig model. In an initial experiment, isolates 12939, MN-H, and 29755 caused Glässer's disease, while strain SW114 failed to cause any clinical signs of disease. One pig from each group challenged with MN-H or 29755 failed to develop clinical disease but were able to transmit the H. parasuis to naïve pigs that subsequently developed Glässer's disease. Pigs colonized with SW114, 29755, or MN-H that were free of clinical disease were protected from rechallenge with isolate 12939. In a following experiment, pigs vaccinated with strain SW114 given as either a bacterin intramuscularly or a live intranasal vaccine were protected from subsequent challenge with isolate 12939; however, some pigs given live SW114 developed arthritis. Overall these studies demonstrate that pigs infected with virulent isolates of H. parasuis can remain healthy and serve as reservoirs for transmission to naïve pigs, and heterologous protection among H. parasuis isolates is possible. In addition, further attenuation of strain SW114 is necessary if it is to be used as a live vaccine.


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