Project description:Using integrated genomics we identify a role for CLEC12A in antibacterial autophagy. Clec12a-/- mice are more susceptible to bacterial infection and CLEC12A deficient cells exhibit impaired antibacterial autophagy. We used transcriptional profilinf to understand the role of CLEC12A in the response to Salmonella and Listeria. Bone marrow-derived macrophages from WT or Clec12a-/- mice were infected with Salmonella enterica serovar Typhimurium or Listeria monocytogenes. Cells were harvested at 0,3,6, and 24hours post-infection for RNA analysis. Please note that single-end sequencing was performed but two files: R1 files that contained the sample barcodes (19 or 17bp reads) and R2 files that contained the single-end-sequenced 46bp cDNA reads were generated. Since the barcode info is mostly redundant, only R2 reads were submitted (described in 'raw_file_readme.txt').
Project description:Species from Escherichia, Campylobacter, Salmonella, Vibrio, Listeria and from other related genera. Genome sequencing and assembly
Project description:Obacunone is a limonoids present in Citrus species. We previously reported that obacunone was inhibitory to the cell-cell signaling in Vibrio harveyi and Escherichia coli O157:H7. In the present work we evaluated the effect of obacunone on the food borne pathogen Salmonella Typhimurium LT2 using cDNA microarray. The results demonstrate that obacunone exerts an antivirulence effect on S. Typhimurium LT2 by repressing SPI1 and SPI2. Furthermore, the effect of obacunone seems to be dependent upon EnvZ.
Project description:Calves are highly susceptible to gastrointestinal infection with Cryptosporidium parvum (C. parvum), which can result in watery diarrhea and eventually death or impaired development. With little to no effective therapeutics, understanding the host’s microbiota and pathogen interaction at the mucosal immune system has been critical to identify and test novel control strategies. We used an experimental model of C. parvum challenge in neonatal calves to describe the clinical signs and mucosal innate immune and microbiota hallmarks in the ileum and colon during cryptosporidiosis and investigated the impact of supplemental colostrum feeding on C. parvum infection. The C. parvum challenged calves experienced clinical signs including pyrexia and diarrhea 5 days post challenge. These calves showed ulcerative neutrophil ileitis with a proteomic signature driven by inflammatory effectors, including reactive oxygen species and myeloperoxidases. Colitis was also noticed with an aggravated mucin barrier depletion and lack of full filled mucin granule in goblet cells. The C. parvum challenged calves also displayed a pronounced dysbiosis with a high prevalence of Clostridium species (spp.) and number of exotoxins, adherence factors, and secretion systems related to Clostridium spp. and other enteropathogens, including Campylobacter spp., Escherichia sp., Shigella spp., and Listeria spp. Daily supplementation with a high-quality bovine colostrum product mitigated some of the clinical signs and modulated the gut immune response and concomitant microbiota to a pattern more similar to that of healthy unchallenged calves.
Project description:Background Compelling evidence indicates that Shigella species, the etiologic agents of bacillary dysentery, as well as enteroinvasive Escherichia coli, are derived from multiple origins of Escherichia coli and form a single pathovar. To further understand the genome diversity and virulence evolution of Shigella, comparative genomic hybridization microarray analysis was employed to compare the gene content of E. coli K-12 with those of 43 Shigella strains from all serotypes. Results For the 43 strains subjected to CGH microarray analyses, the common backbone of the Shigella genome was estimated to contain more than 1,900 open reading frames, with a mean number of 729 undetectable ORFs. The mosaic distribution of absent regions indicated that insertions and/or deletions have led to the highly diversified genomes of pathogenic strains. Conclusion These results support the hypothesis that by gain and loss of functions, Shigella species became successful human pathogens through convergent evolution from diverse genomic backgrounds. Moreover, we also found many specific differences between different lineages, providing a window into understanding bacterial speciation and taxonomic relationships. Keywords: comparative genomic hybridization