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:To reveal the transcriptional profiles of Actinobacillus pleuropneumoniae under biofilm and planktonic growth, we established a biofilm-forming culture method and constructed a mutant strain Δpga with defect in biofilm formation. Wild-type and Δpga mutant strains of Actinobacillus pleuropneumoniae strain 4074 were cultured in bottles with shaking for planktonic (WT_PK) and in microplates in static status for biofilm (WT_BF, Δpga), respectively. The bacteria in logarithmic growth period of different culture groups were collected for RNA seq.
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:To determine the role of Actinobacillus pleuropneumoniae two-component system QseBQseC, we constructed a qseBqseC gene-deleted mutant ΔqseBΔqseC based on the wild type A. pleuropneumoniae 4074. The transcriptional profiles were compared between the A. pleuropneumoniae ΔqseBΔqseC and its parental strain under the normal growth condition using microarray. A total of 44 genes were found differentially expressed (DE) compared to the wild type strain. These functional genes are primarily related to metabolism, cell wall biogenesis, energy, replication and recombination. Further investigations indicated that the type IV pili (Tfp) assembly protein PilM is regulated directly by QseB, and PilM is essential for adherence and virulence. Characterization of the QseBQseC regulon genes will provides new insight into understanding of the relevant signal transduction pathways and prevention of the infection.
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. Comparative Genomic Hybridizations between Actinobacillus pleuropneumoniae serotype 5b strain L20 (ref) and serotype 5b fresh field isolate 896-07, recovered from infected pig lung tissues following natural acute infection. Two condition transcript profiling experiments : infectious 5b field strain isolated directly from lungs of naturally deceased pigs after acute infection vs infectious 5b field strain grown in BHI broth to an OD600 of 0.300.
Project description:To determine the role of Actinobacillus pleuropneumoniae two-component system QseBQseC, we constructed a qseBqseC gene-deleted mutant ΔqseBΔqseC based on the wild type A. pleuropneumoniae 4074. The transcriptional profiles were compared between the A. pleuropneumoniae ΔqseBΔqseC and its parental strain under the normal growth condition using microarray. A total of 44 genes were found differentially expressed (DE) compared to the wild type strain. These functional genes are primarily related to metabolism, cell wall biogenesis, energy, replication and recombination. Further investigations indicated that the type IV pili (Tfp) assembly protein PilM is regulated directly by QseB, and PilM is essential for adherence and virulence. Characterization of the QseBQseC regulon genes will provides new insight into understanding of the relevant signal transduction pathways and prevention of the infection. A. pleuropneumoniae strains were cultured in TSB medium supplemented with 10 μg/ml of nicotinamide adenine dinucleotide (NAD) and 10% (v/v)filtered cattle serum at 37℃. The samples were collected at the mid-exponential phase and the total RNA were extracted using RNA-Solv Reagent (Omega) according to the manufacturer’s instructions. Expression profiles of two different Actinobacillus pleuropneumoniae (4074 and ΔqseBΔqseC) were determined. The fold changes >=1.5 or <=-1.5 were selected as differentially expressed genes.
Project description:Understanding constraints which shape antibiotic resistance is key for predicting and controlling drug resistance. Here, we performed high-throughput laboratory evolution of Actinobacillus pleuropneumoniae and its ciprofloxacin resistance-inducing derivatives.This study aims to explore the mechanism of acquired ciprofloxacin resistance in Actinobacillus pleuropneumoniae.