Project description:Streptococcus suis serotype 2 (SS2), a major swine pathogen and an emerging zoonotic agent, has greatly challenged global public health. Systematical information about host immune response to the infection is important for understanding the molecular mechanism of diseases. Here, we investigated the global expression changes in spleen following SS2 infection using the Affymetrix Porcine Genechip. Our findings indicate previously unrecognized gene transcription changes in case of SS infection in vivo. Our data should provide new clues for immune response in mammals and identification of candidate genes related to SS resistance.
Project description:Background: Swine influenza is a highly contagious viral infection in pigs affecting the respiratory tract that can have significant economic impacts. Streptococcus suis serotype 2 is one of the most important post-weaning bacterial pathogens in swine causing different infections, including pneumonia. Both pathogens are important contributors to the porcine respiratory disease complex. Outbreaks of swine influenza virus with a significant level of co-infections due to S. suis have lately been reported. In order to analyze a global response to the dual infection, we carried out a comprehensive gene expression profiling using a microarray approach to study the swine tracheal epithelial (NPTr) cell response to a co-infection with H1N1 swine influenza virus (swH1N1) and S. suis serotype 2. Results: Gene clustering showed that the swH1N1 and swH1N1/S. suis infections modified the expression of genes in a similar manner. Additionally, infection of NPTr cells by S. suis alone did not result in many differentially expressed genes compared to mock-infected cells. However, some important genes coding for inflammatory mediators, such as chemokines, interleukins, cell adhesion molecules and eicosanoids, were significantly upregulated in the presence of both pathogens comparing to infection with each pathogen taken individually. This synergy may also be the consequence of an increased adhesion/invasion of epithelial cells previously infected by swH1N1, as recently reported. Conclusion: In a co-infection situation, influenza virus would replicate in the respiratory epithelium inducing an inflammatory infiltrate comprised of mononuclear cells and neutrophils. Despite that these cells are unable to phagocyte and kill S. suis, they are highly activated by this pathogen. S. suis is not considered a primary pulmonary pathogen, but an exacerbated production of pro-inflammatory mediators during a co-infection with influenza virus may be of critical importance in the pathogenesis and outcome of this respiratory disease complex.
Project description:Swine streptococcosis has caused great economic loss in the swine industry, and the major pathogen responsible for this disease is Streptococcus Suis serotype 2 (SS2). Disease resistance breeding is a fundamental way of resolving this problem. With the development of GWAS and transcriptomic microarray technology, we now have powerful research tools to identify SS2 resistance genes. In this research, we generated an F2 generation of SS2 resistant C57BL/6 and SS2 susceptive A/J mice. With the F2 generation of these two mice strains and GWAS analysis, we identified 286 significant mouse genome SNPs sites associated with the SS2 resistance trait. Gene expression profiles for C57BL/6 and A/J were analyzed under SS2 infection pressure by microarray. In total, 251 differentially expressed genes were identified between these two mouse strains during SS2 infection. After combining the GWAS and gene expression profile data, we located two genes that were significantly associated with SS2 resistance, which were the UBA domain containing 1 gene (Ubac1) and Epsin 1 gene (Epn 1). GO classification and over-representation analysis revealed nine up-regulated related to immune function, which could potentially be involved in the C57BL/6 SS2 resistance trait. This is the first study to use both SNP chip and gene express profile chip for SS2 resistance gene identification in mouse, and these results will contribute to Swine SS2 resistance breeding.
Project description:Erysipelothrix rhusiopathiae is generally regarded as an opportunistic pathogen that causes erysipelas in swine and other diseases in several mammalian and avian species.This study aimed to perform a whole-genomic analysis of the transcriptional responses of a pig heart to virulent and avirulent strains and PBS by using Affymetrix Porcine Gene 1.0 ST Microarray to elucidate the immune responses of hosts to E. rhusiopathiae.