Project description:Gene expression profiling of clostridium perfringens infection in broilers on medicated and non-medicated diets using chicken 44k agilent microarray. To elucidate molecular and ceelular mechanisms of bacitracin effect on CP infection in chickens by microarray technology.
Project description:Necrotic enteritis is a disease caused by Clostridium perfringens, which threatens poultry production in the absence of dietary antibiotics. A total number of 144 Ross broilers were reared in 12 pens with each hosting 12 birds. Each 6 pens of birds were fed medicated (bacitracin at 55 ppm) or non-medicated starter diets (Nutreco Canada Agresearch) immediately after the chicks were placed. At day 18, birds were challenged with C. perfringens (107 cfu per ml mixed with feed). Spleens were collected from 12 birds of each group at day 18 (before infection), 19, 20, and 22. A low-density chicken immune microarray was used to study gene expression profiling of host response to C. perfringens infection. Six biological replicates (2 birds per biological replicate) for each treatment group were labeled with either Cy5 or Cy3 with dye swap. A total of 24 arrays were used for this study. Gene signal intensity was globally normalized by LOWESS and expressed as log2 ratios. A mixed model including treatment, time, array, subgrid (random effect), dye, and all interactions among treatment and time was used to identify differentially expressed genes between post-infection vs. pre-infection, among post-infections, and between medication treatments, at the 5% significance level. The results indicated subtle medication effects on gene expression of these immune-related genes compared to bacterial infection effect. Our findings strongly suggest that both cell-mediated and antibody-mediated immune responses via MHC class I and II systems were actively involved in the host defense against C. perfringens infection in broilers. The unique cytokine signaling pathway and apoptosis cascade found in the study provide a new insight of molecular regulation of host immune response. Collectively, the findings of the present study will shed light on the molecular mechanisms underlying C. perfringens infection in broilers.
Project description:Necrotic enteritis is a disease caused by Clostridium perfringens, which threatens poultry production in the absence of dietary antibiotics. A total number of 144 Ross broilers were reared in 12 pens with each hosting 12 birds. Each 6 pens of birds were fed medicated (bacitracin at 55 ppm) or non-medicated starter diets (Nutreco Canada Agresearch) immediately after the chicks were placed. At day 18, birds were challenged with C. perfringens (107 cfu per ml mixed with feed). Spleens were collected from 12 birds of each group at day 18 (before infection), 19, 20, and 22. A low-density chicken immune microarray was used to study gene expression profiling of host response to C. perfringens infection. Six biological replicates (2 birds per biological replicate) for each treatment group were labeled with either Cy5 or Cy3 with dye swap. A total of 24 arrays were used for this study. Gene signal intensity was globally normalized by LOWESS and expressed as log2 ratios. A mixed model including treatment, time, array, subgrid (random effect), dye, and all interactions among treatment and time was used to identify differentially expressed genes between post-infection vs. pre-infection, among post-infections, and between medication treatments, at the 5% significance level. The results indicated subtle medication effects on gene expression of these immune-related genes compared to bacterial infection effect. Our findings strongly suggest that both cell-mediated and antibody-mediated immune responses via MHC class I and II systems were actively involved in the host defense against C. perfringens infection in broilers. The unique cytokine signaling pathway and apoptosis cascade found in the study provide a new insight of molecular regulation of host immune response. Collectively, the findings of the present study will shed light on the molecular mechanisms underlying C. perfringens infection in broilers. There were two groups: medicated and non-medicated. Spleen were collected to isolate total RNA for gene expression profiling.For the microarray study, two birds from each pen were pooled within each group. To account for any bias inherent to the fluorescent dyes, three of the six medicated replicates were labeled with Cy3 and the other three were labeled with Cy5 at each time point. The same design was applied for the non-medicated group. There were six hybridizations between medicated and non-medicated replicates at each time point. Twenty-three out of 24 arrays were used (data from one array were discarded due to poor quality).
Project description:Gene expression profiling of clostridium perfringens infection in broilers on medicated and non-medicated diets using chicken 44k agilent microarray. To elucidate molecular and ceelular mechanisms of bacitracin effect on CP infection in chickens by microarray technology. A total number of 600 Ross broilers were reared in 12 pens with each hosting 50 birds. Each 6 pens of birds were fed bacitracin-medicated (55 ppm) or non-medicated starter diets immediately after the chicks were placed. At day 18, birds were challenged with CP. Spleens were collected from 12 birds of each group at day 18 (before infection), 19, 20, and 22. Total RNA was labeled by Cy3 or Cy5 with dye swap. Gene signal intensity was globally normalized by LOWESS and expressed on natural log scale. A mixed model including treatment, time, array (random effect), dye, and all interactions among treatment, time was used to identify differentially expressed genes between treatments, at the 1% significance level.
Project description:Necrotic enteritis (NE) in broiler chickens, caused by the overgrowth of toxin-producing strains of Clostridium (C.) perfringens, results in the development of necrotic lesions, compromised intestinal health, and significant economic losses in poultry production. This study aims to analyze the blood proteome of broiler chickens affected by NE, providing insights into the host's response to the infection. Using MS/MS-based proteomics, blood plasma samples from broilers with necrotic lesions of different severity were analyzed and compared to healthy controls. A total of 412 proteins were identified, with 63 showing significant differences and (for some of those) correlating with disease severity. Gene Set Enrichment Analysis (GSEA) revealed that proteins affected by NE were predominantly associated with the immune and signaling processes and extracellular matrix (ECM) structures. Notably, regulated proteins were significantly involved in bioprocesses related to complement activation, acute phase reaction, proteolysis and humoral immune response. The findings suggest that the changes in plasma proteins in response to NE are driven by the host's intensified efforts to counteract the infection, demonstrating a.o. a notable reduction in peptides from ECM-related proteins in the blood of NE-affected birds. Overall, proteomics results underscored the attempts of the host to manage tissue damage and inflammation, indicating a coordinated effort to mitigate the pathogenic impact of C. perfringens. This study provides a deeper understanding of the host-pathogen interactions and potential targets for therapeutic intervention.
Project description:Purpose: The purpose of this study is to clarify the response of Clostridium perfringens ATCC 13124 to host polysaccharide. Methods: Clostridium perfringens ATCC 13124 cells were cultured anaerobically in a medium containing Minimal medium-like condition Poor + medium, medium in which hyaluronic acid or mucin was added to Poor + medium. Total RNA was extracted from bacterial cells by the Hot-Phenol method. Samples for RNA-seq were prepared according to the Illmina protocol available from the manufacturer. Array leads passed through quality filters were analyzed at the transcript isoform level using bowtie v 1.1.2. Results: Using the optimized data analysis workflow, we mapped about 50 million sequence leads per sample to the whole genome of Clostridium perfringens ATCC 13124. In addition, 2735 transcripts in C. perfringens ATCC 13124 were identified using a Bowtie aligner. Lead counts per genome were extracted from known gene annotations using the HTSeq program.
Project description:RNA-seq was employed for comparative analysis of the transcriptomes of both the pathogen and the host in C. perfringens-infected murine muscle lesions. The aim was to identify C. perfringens genes that were induced in the host environment and host signaling cascades that were activated in response to a C. perfringens infection.
Project description:Upon infection, pathogens reprogram host gene expression. In eukaryotic cells, genetic reprogramming is induced by the concerted activation/repression of transcription factors and various histone modifications that control DNA accessibility in chromatin. We report here that the bacterial pathogen, Listeria monocytogenes, induces a dramatic dephosphorylation of histone H3 as well as a deacetylation of histone H4 during early phases of infection. This effect is mediated by the major listerial toxin listeriolysin (LLO), in a pore forming independent manner. Strikingly, a similar effect is also observed with other toxins of the same family, such as Clostridium perfringens perfringolysin (PFO) and Streptococcus pneumoniae pneumolysin (PLY). The decreased levels of histone modifications correlate with a reduced transcriptional activity of a subset of host genes, including key immunity genes. Thus, manipulation of the epigenetic information emerges here as an unsuspected function shared by several bacterial toxins, highlighting a common strategy used by intracellular and extracellular pathogens to modulate the host response early during infection.
Project description:With the development of the poultry industry, ammonia, as a main contaminant in the air, is causing increasing problems with broiler health. To date, most studies of ammonia toxicity have focused on the nervous system and the gastrointestinal tract in mammals. However, few detailed studies have been conducted on the hepatic response to ammonia toxicity in poultry. The molecular mechanisms that underlie these effects remain unclear. In the present study, our group applied isobaric tags for relative and absolute quantitation (iTRAQ) - based quantitative proteomic analysis to investigate changes in the protein profile change in hepatic tissue of broilers exposed to high concentrations of atmospheric ammonia, with the goal of characterizing the molecular mechanisms of chronic liver injury from exposure to high ambient levels of ammonia. Overall, 30 differentially expressed proteins that are involved in nutrient metabolism (energy, lipid and amino acid), immune response, transcriptional and translational regulation, stress response and detoxification were identified. In particular, two of these proteins, beta-1 galactosidase (GLB1), and a kinase (PRKA) anchor protein 8-like (AKAP8 L), were previously suggested to be potential biomarkers of chronic liver injury. In addition to the changes in the protein profile, serum parameters and histochemical analyses of hepatic tissue also showed extensive hepatic damage in ammonia-exposed broilers. Altogether, these findings suggest that longtime exposure to high concentrations of atmospheric ammonia can trigger chronic hepatic injury in broilers via different mechanisms, providing new information that can be used for intervention using nutritional strategies in the future.