Project description:Actinobacillus pleuropneumoniae is the etiologic agent of contagious pleuropneumonia, an economically important disease of commercially reared swine throughout the world. To cause this disease, A. pleuropneumoniae must rapidly overcome porcine pulmonary innate immune defenses. Effects of koromycin, an antimicrobial agent that acts as an noncompetitive inhibitor of the interaction of NQR with its quinone substrate, on the transcriptome of A. pleuropneumoniae was investigated.
Project description:Actinobacillus pleuropneumoniae is the etiologic agent of contagious pleuropneumonia, an economically important disease of commercially reared swine throughout the world. To cause this disease, A. pleuropneumoniae must rapidly overcome porcine pulmonary innate immune defenses. Since bronchoalveolar fluid (BALF) contains many of the innate immune components found in the lung, we examined the gene expression of a virulent serovar 1 strain of A. pleuropneumoniae after exposure to concentrated BALF. This experiment was also carried out with a malT mutant of the same strain.
Project description:Porcine pleuropneumonia caused by Actinobacillus pleuropneumoniae affects pig health status and the swine industry worldwide. Despite of the extensive number of studies focused on A. pleuropneumoniae infection and vaccine development, its exoproteome is still rather unexplored. By combining high-throughput mass spectrometry and immunoproteomic approaches, with our current work we provide an in-depth characterisation of A. pleuropneumoniae serotype 2 exoproteome. Label-free liquid chromatography - tandem mass spectrometry (LC-MS/MS) combined with a comprehensive bioinformatics analysis revealed 484 secreted proteins, of which 84 were predicted to be virulence factors and 142 to be exported via different export mechanisms. The RTX toxins ApxIIA, ApxIIIA and ApxIVA were found to be the most abundant proteins in the A. pleuropneumoniae serotype 2 exoproteome, although ApxIVA is commonly assumed to be expressed exclusively in vivo. Immunoproteomic approaches coupled to LC-MS/MS analysis allowed to portray the immunogenic proteins within the bacterial exoproteome to identify potential vaccine candidates. Using serum pools from uninfected, acutely infected and chronically infected animals, we were able to monitor the seroconversion during disease progression. Overall, our work is expected to contribute to the understanding of the complex pathogenic mechanisms and to facilitate the discovery of potential antimicrobial agents for controlling porcine pleuropneumonia.
Project description:Actinobacillus pleuropneumoniae is the etiological agent of porcine pleuropneumonia, a respiratory disease which causes great economic losses worldwide. Many virulence factors are involved in the pathogenesis, namely capsular polysaccharides, RTX toxins, LPS and many iron acquisition systems. In order to identify genes that are expressed in vivo during a natural infection, we undertook transcript profiling experiments with an A. pleuropneumoniae DNA microarray, after recovery of bacterial mRNAs from serotype 5b-infected porcine lungs.
Project description:Actinobacillus pleuropneumoniae is a gram-negative bacterium that causes porcine pleuropneumonia, which is a widespread, highly contagious, and often fatal respiratory disease in swine. In this experiment pigs were inoculated with A. pleuropneumoniae serotype 5b. Liver samples from three non-inoculated pigs and three experimental inoculated pigs were used to characterize the expression profiles of mRNA and microRNA genes using DNA microarrays and Illumina GA deep sequencing, respectively. The microarray analysis identified a large number of genes, which significantly differed in expression in infected versus non-infected animals. MicroRNAs are short single stranded RNA molecules that regulate gene expression by sequence specific binding to the 3´ untranslated region (3´UTR) of target mRNAs. The deep sequencing analysis determined the identity and abundance of nearly 400 microRNAs, of which a portion was found to significantly differ in expression between the infected and non-infected animals. Target genes for differentially expressed microRNAs were predicted using microCosm Targets, which is based on the miRanda algorithm. Comparison on the two gene lists showed many common genes, which may suggest a causative relationship between changes in microRNA expression and target gene expression.
Project description:Actinobacillus pleuropneumoniae is a gram-negative bacterium that causes porcine pleuropneumonia, which is a widespread, highly contagious, and often fatal respiratory disease in swine. In this experiment pigs were inoculated with A. pleuropneumoniae serotype 5b. Liver samples from three non-inoculated pigs and three experimental inoculated pigs were used to characterize the expression profiles of mRNA and microRNA genes using DNA microarrays and Illumina GA deep sequencing, respectively. The microarray analysis identified a large number of genes, which significantly differed in expression in infected versus non-infected animals. MicroRNAs are short single stranded RNA molecules that regulate gene expression by sequence specific binding to the 3M-BM-4 untranslated region (3M-BM-4UTR) of target mRNAs. The deep sequencing analysis determined the identity and abundance of nearly 400 microRNAs, of which a portion was found to significantly differ in expression between the infected and non-infected animals. Target genes for differentially expressed microRNAs were predicted using microCosm Targets, which is based on the miRanda algorithm. Comparison on the two gene lists showed many common genes, which may suggest a causative relationship between changes in microRNA expression and target gene expression. The expression profiles of mRNA and smallRNA in liver from three experimentally infected pigs were compared with the profiles three non-infected contol pigs.