Project description:Full title: Probing the pan genome of a foodborne bacterial pathogen Listeria monocytogenes: Implications for its niche adaptation, pathogenesis, and evolution Listeria monocytogenes is a foodborne bacterial pathogen well known for adaptability to diverse environmental and host niches, and a high fatality rate among infected, immuno-compromised individuals. Three genetic lineages have been identified within this species. Strains of genetic lineages I and II account for more than ninety percent of foodborne disease outbreaks worldwide, whereas strains from genetic lineage III are rarely implicated in human infectious for unknown, yet intriguing, reasons. Here we have probed the genomic diversity of 26 L. monocytogenes strains using both whole-genome sequences and a novel 385,000 probe pan-genome microarray, fully tiling the genomes of 20 representative strains. Using these methods to identify genes highly conserved in lineages I and II but rare in lineage III, we have identified 86 genes and 8 small RNAs that play roles in bacterial stress resistance, pathogenicity, and niche, potentially explaining the predominance of L. monocytogenes lineages I and II in foodborne disease outbreaks. Extending gene content analysis to all lineages revealed a L. monocytogenes core genome of approximately 2,350 genes (80% of each individual genome) and a pan-genomic reservoir of >4,000 unique genes. Combined gene content data from both sequences and arrays was used to reconstruct an informative phylogeny for the L. monocytogenes species that confirms three distinct lineages and describes the relationship of 9 new lineage III genomes. Comparative analysis of 18 fully sequenced L. monocytogenes lineage I and II genomes shows a high level of genomic conservation and synteny, indicative of a closed pan-genome, with moderate domain shuffling and sequence drift associated with bacteriophages is present in all lineages. In contrast with lineages I and II, notable genomic diversity and characteristics of an open pan-genome were observed in the lineage III genomes, including many strain-specific genes and a more complex conservation pattern. This indicates that the L. monocytogenes pan-genome has not yet been fully sampled by genome sequencing, and additional sequencing of lineage III genomes is necessary to survey the full diversity of this intriguing species and reveal its mechanisms for adaptability and virulence.
Project description:Full title: Probing the pan genome of a foodborne bacterial pathogen Listeria monocytogenes: Implications for its niche adaptation, pathogenesis, and evolution Listeria monocytogenes is a foodborne bacterial pathogen well known for adaptability to diverse environmental and host niches, and a high fatality rate among infected, immuno-compromised individuals. Three genetic lineages have been identified within this species. Strains of genetic lineages I and II account for more than ninety percent of foodborne disease outbreaks worldwide, whereas strains from genetic lineage III are rarely implicated in human infectious for unknown, yet intriguing, reasons. Here we have probed the genomic diversity of 26 L. monocytogenes strains using both whole-genome sequences and a novel 385,000 probe pan-genome microarray, fully tiling the genomes of 20 representative strains. Using these methods to identify genes highly conserved in lineages I and II but rare in lineage III, we have identified 86 genes and 8 small RNAs that play roles in bacterial stress resistance, pathogenicity, and niche, potentially explaining the predominance of L. monocytogenes lineages I and II in foodborne disease outbreaks. Extending gene content analysis to all lineages revealed a L. monocytogenes core genome of approximately 2,350 genes (80% of each individual genome) and a pan-genomic reservoir of >4,000 unique genes. Combined gene content data from both sequences and arrays was used to reconstruct an informative phylogeny for the L. monocytogenes species that confirms three distinct lineages and describes the relationship of 9 new lineage III genomes. Comparative analysis of 18 fully sequenced L. monocytogenes lineage I and II genomes shows a high level of genomic conservation and synteny, indicative of a closed pan-genome, with moderate domain shuffling and sequence drift associated with bacteriophages is present in all lineages. In contrast with lineages I and II, notable genomic diversity and characteristics of an open pan-genome were observed in the lineage III genomes, including many strain-specific genes and a more complex conservation pattern. This indicates that the L. monocytogenes pan-genome has not yet been fully sampled by genome sequencing, and additional sequencing of lineage III genomes is necessary to survey the full diversity of this intriguing species and reveal its mechanisms for adaptability and virulence. This is a Listeria monocytogenes pan-genome tilling array designed using PanArray algorithm. 9 experimental strains (F2-569, M1-002, F2-208, J2-071, J1-208, W1-111, W1-110, F2-524, F2-501) vs reference (EGD-e) strain.
Project description:Understanding the gene regulation of plant pathogens is crucial for pest control and thus global food security. An integrated understanding of bacterial gene regulation in the host is dependent on multi-omic datasets, but these are largely lacking. Here, we simultaneously characterized the transcriptome and proteome of a bacterial pathogen in plants. We found a number of bacterial processes affected by plant immunity at the transcriptome and proteome levels. For instance, the salicylic acid-mediated plant immunity suppressed the accumulation of proteins comprising the tip component of bacterial type III secretion system. Interestingly, there were instances of concordant and discordant regulation of bacterial mRNAs and proteins. Gene co-expression analysis uncovered previously unknown gene regulatory modules underlying virulence. This study provides molecular insights into the multiple layers of gene regulation that contribute to bacterial growth in planta and elucidate the role of plant immunity in affecting pathogen responses.
Project description:We report the application of Solexa/Illumina's digital gene expression (DGE) sequencing approaches to investigate inactivated Vibrio harveyi--induced transcriptome changes in Lateolabrax japonicas, a non model vertebrate species. Totally 3.44 and 3.22 million raw tags were measured. Then, gene annotation was performed by tags mapping analysis and the 169,950 non-redundant consensus sequences from RNA-seq based transcriptome analysis were used as reference transcript database. Tag mapping indicated that Vibrio harveyi--challenged adult Lateolabrax japonicas express over 70% of all genes represented in transcript databases. Meanwhile, totally 1224 consensus sequences exhibited significant difference after the bacterial challenge, in which 1183 transcripts can be well annotated, while approximately 41 transcripts have low sequence homology to the existing known sequences in public databases, suggesting that they might be putative novel immune-relevant genes in Lateolabrax japonicus closely related to the immunity for bacterial challenge. Our present study would greatly benefit to give deep insight into the immunogenetics in fish species, and clinical application in fish diseases. Examination of differentially expressed transcripts in baterial- and mock challenged fish.
Project description:We report the application of Solexa/Illumina's digital gene expression (DGE) sequencing approaches to investigate inactivated Vibrio harveyi--induced transcriptome changes in Lateolabrax japonicas, a non model vertebrate species. Totally 3.44 and 3.22 million raw tags were measured. Then, gene annotation was performed by tags mapping analysis and the 169,950 non-redundant consensus sequences from RNA-seq based transcriptome analysis were used as reference transcript database. Tag mapping indicated that Vibrio harveyi--challenged adult Lateolabrax japonicas express over 70% of all genes represented in transcript databases. Meanwhile, totally 1224 consensus sequences exhibited significant difference after the bacterial challenge, in which 1183 transcripts can be well annotated, while approximately 41 transcripts have low sequence homology to the existing known sequences in public databases, suggesting that they might be putative novel immune-relevant genes in Lateolabrax japonicus closely related to the immunity for bacterial challenge. Our present study would greatly benefit to give deep insight into the immunogenetics in fish species, and clinical application in fish diseases.
Project description:Vibrio vulnificus is a marine zoonotic pathogen associated with fish farms that is considered a biomarker of climate change. Zoonotic strains trigger a rapid death of their susceptible hosts (fish or humans) by septicemia that has been linked to a cytokine storm in mice. A toxin called RtxA1 produced by the bacteria might play an important role in bacterial invasion and subsequent death by septic shock since animals infected with a mutant deficient in rtxA1 suffer from septicemia but do not die. The aim of this study was to globally analyze the early eel immune response in blood against V. vulnificus, as well as the role of the RtxA1 toxin on this interaction.
Project description:We report the application of Solexa/IlluminaM-bM-^@M-^Ys RNA-seq sequencing approaches for transcriptome in a marine fish under different conditions (bacterial- and mock-challenged conditions). By obtaining over four billion bases of sequence from the cDNA, we generated 169,950 none-redundant consensus sequences, from which 44842 functional transcripts with complete or various length of encoding regions were identified. More than 52% of these transcripts could be enriched in approximately 219 known metabolic or signaling pathways, among of which 2673 transcripts were found to be associated with immune-relevant genes. Besides, about 8% of the transcripts seemed fish-specific genes that have never been described before. This study provides a framework for the application of comprehensive chromatin profiling towards characterization of diverse mammalian cell populations. Our study provided a global survey of the gene activities in host defense against bacterial infection in a non-model marine fish. Examination of different transcriptome in baterial- and mock challenged fish.
Project description:We report the application of Solexa/Illumina’s RNA-seq sequencing approaches for transcriptome in a marine fish under different conditions (bacterial- and mock-challenged conditions). By obtaining over four billion bases of sequence from the cDNA, we generated 169,950 none-redundant consensus sequences, from which 44842 functional transcripts with complete or various length of encoding regions were identified. More than 52% of these transcripts could be enriched in approximately 219 known metabolic or signaling pathways, among of which 2673 transcripts were found to be associated with immune-relevant genes. Besides, about 8% of the transcripts seemed fish-specific genes that have never been described before. This study provides a framework for the application of comprehensive chromatin profiling towards characterization of diverse mammalian cell populations. Our study provided a global survey of the gene activities in host defense against bacterial infection in a non-model marine fish.
Project description:This study established immunological and particularly antibacterial proteins in the skin mucus of Obscure puffer against A. hydrophila infection. These proteins could be potential biomarkers to be studied for prevention of bacterial disease in fish. Overall, the study provides primary insights into the mucosal immune factors in the skin mucus of fish and recommends each protein for functional-based molecular studies.
Project description:Gene regulation of bacterial pathogens in the host is not comprehensively understood due to the difficulty in analyzing genome-wide mRNA and protein expression of bacteria during infection. Here, we jointly analyzed transcriptome and proteome of a foliar bacterial pathogen in plants. Bacterial transcriptome changes can explain to a large extent their proteome changes in resistant and susceptible plants. However, a part of bacterial type III secretion system was suppressed by plant immunity preferentially at the protein level. Also, gene co-expression analysis uncovered previously unknown gene regulatory modules underlying bacterial virulence. Collectively, integrated in planta bacterial omics provides molecular insights into multiple layers of bacterial gene regulation that contributes to virulence and roles of plant immunity in controlling it.