Project description:Little is known about the extent of genetic variability among Entamoeba strains and potential genotypic associations with virulence. Variable phenotypes have been identified for Entamoeba strains. E. histolytica is invasive and causes colitis and liver abscesses, but only in 10% of infected individuals; 90% of subjects remain asymptomatically colonized. E. dispar, a closely related species, appears to be incapable of causing invasive disease. In order to determine the extent of genetic diversity among Entamoeba strains we have developed an E. histolytica genomic DNA microarray and used it to genotype strains of E. dispar and E. histolytica. Based on the identification of divergent genetic loci, all six strains (four EH and two ED) had unique genetic fingerprints. Genomic regions with unusually high levels of divergence were identified indicating that structural or evolutionary pressures are molding selective regions of the Entamoeba genome. Comparison of divergent genetic regions allowed us to readily distinguish between EH and ED, identify novel genetic regions that may be used for strain and species typing, and identity a number of novel potential virulence determinants. Among these are Androgen Inducible Gene1, a CXXC receptor kinase, a peroxiredoxin 1-related gene, a Ras family member gene, a Rab geranylgeranyltransferase, and a gene with a UPF0034 domain. Among the four EH strains, an avirulent strain EH (Rahman) was the most divergent and phylogenetically distinct raising the intriguing possibility that genetic subtypes of E. histolytica may be at least partially responsible for the observed variability in clinical outcomes. Our approach shows the utility of a microarray-based genotyping assay to identify genetic variability between Entamoeba isolates and can readily be applied to the study of clinical isolates. A genotyping experiment design type classifies an individual or group of individuals on the basis of alleles, haplotypes, SNP's. Keywords: genotyping_design
Project description:Helicobacter pylori colonizes the stomach of half of the world's population, causing a wide spectrum of disease ranging from asymptomatic gastritis to ulcers to gastric cancer. Although the basis for these diverse clinical outcomes is not understood, more severe disease is associated with strains harboring a pathogenicity island. To characterize the genetic diversity of more and less virulent strains, we examined the genomic content of 15 H. pylori clinical isolates by using a whole genome H. pylori DNA microarray. We found that a full 22% of H. pylori genes are dispensable in one or more strains, thus defining a minimal functional core of 1281 H. pylori genes. While the core genes encode most metabolic and cellular processes, the strain-specific genes include genes unique to H. pylori, restriction modification genes, transposases, and genes encoding cell surface proteins, which may aid the bacteria under specific circumstances during their long-term infection of genetically diverse hosts. We observed distinct patterns of the strain-specific gene distribution along the chromosome, which may result from different mechanisms of gene acquisition and loss. Among the strain-specific genes, we have found a class of candidate virulence genes identified by their coinheritance with the pathogenicity island. Keywords: other
Project description:The genetic diversity of JEV vaccine strains SA14-14-2, SA14-5-3 and SA14-2-8 and the WT parental WT strain they were derived from, SA14, were sequenced using Illumina technology. Passages of the strains were also sequenced to observe changes in genetic diversity.
Project description:Herpesviruses have a group of genes earmarked for expression late in the infection. Beta- and gammaherpesviruses utilize a six-member set of viral late transcription factors to selectively activate these genes by binding to a DNA sequence signature in gene promoters. We made an unexpected discovery that differences in sequence signature configures the late gene expression program for human cytomegalovirus, a beta-herpesvirus of global public health importance. Diversity in signature patterns expands promoter targets and pre-sets amount of individual promoter output. A unique palindromic sequence signature is linked to the activation of back-to-back promoters at multiple locations in the viral genome. We deduce that diversity in late transcription factor targets functionally orchestrates the productive rollout of the late-stage infection. This may be a generalizable feature adopted by beta- and gammaherpesvirus subfamilies.
Project description:Helicobacter pylori colonizes the stomach of half of the world's population, causing a wide spectrum of disease ranging from asymptomatic gastritis to ulcers to gastric cancer. Although the basis for these diverse clinical outcomes is not understood, more severe disease is associated with strains harboring a pathogenicity island. To characterize the genetic diversity of more and less virulent strains, we examined the genomic content of 15 H. pylori clinical isolates by using a whole genome H. pylori DNA microarray. We found that a full 22% of H. pylori genes are dispensable in one or more strains, thus defining a minimal functional core of 1281 H. pylori genes. While the core genes encode most metabolic and cellular processes, the strain-specific genes include genes unique to H. pylori, restriction modification genes, transposases, and genes encoding cell surface proteins, which may aid the bacteria under specific circumstances during their long-term infection of genetically diverse hosts. We observed distinct patterns of the strain-specific gene distribution along the chromosome, which may result from different mechanisms of gene acquisition and loss. Among the strain-specific genes, we have found a class of candidate virulence genes identified by their coinheritance with the pathogenicity island.
Project description:Little is known about the extent of genetic variability among Entamoeba strains and potential genotypic associations with virulence. Variable phenotypes have been identified for Entamoeba strains. E. histolytica is invasive and causes colitis and liver abscesses, but only in 10% of infected individuals; 90% of subjects remain asymptomatically colonized. E. dispar, a closely related species, appears to be incapable of causing invasive disease. In order to determine the extent of genetic diversity among Entamoeba strains we have developed an E. histolytica genomic DNA microarray and used it to genotype strains of E. dispar and E. histolytica. Based on the identification of divergent genetic loci, all six strains (four EH and two ED) had unique genetic fingerprints. Genomic regions with unusually high levels of divergence were identified indicating that structural or evolutionary pressures are molding selective regions of the Entamoeba genome. Comparison of divergent genetic regions allowed us to readily distinguish between EH and ED, identify novel genetic regions that may be used for strain and species typing, and identity a number of novel potential virulence determinants. Among these are Androgen Inducible Gene1, a CXXC receptor kinase, a peroxiredoxin 1-related gene, a Ras family member gene, a Rab geranylgeranyltransferase, and a gene with a UPF0034 domain. Among the four EH strains, an avirulent strain EH (Rahman) was the most divergent and phylogenetically distinct raising the intriguing possibility that genetic subtypes of E. histolytica may be at least partially responsible for the observed variability in clinical outcomes. Our approach shows the utility of a microarray-based genotyping assay to identify genetic variability between Entamoeba isolates and can readily be applied to the study of clinical isolates. A genotyping experiment design type classifies an individual or group of individuals on the basis of alleles, haplotypes, SNP's. User Defined
Project description:Staphylococcus saprophyticus is a gram-positive microorganism responsible for urinary tract infections (UTIs). Although some virulence factors have been characterized, such as urease, autolysins, adhesins, hemagglutinins and cell wall proteins, large-scale proteomic studies have not been performed within this species. In our research, we performed the characterization of the exoproteome from three clinical S. saprophyticus strains (ATCC 15305-capsular strain, 7108 non-capsular strain and 9325, a strain containing a thick capsule) which were cultured until the stationary phase of bacterial growth by using mass spectrometry approach. In these strains we observed a core of 72 secreted proteins. In addition, we identified proteins that were not secreted by all the strains. It was possible to detect diversity in the protein profiles of the exoproteomes, and consequently proteins that were differentially expressed were identified. Interestingly, strain 7108 presented no secretion of three antigenic proteins, including the classical SsaA antigen. In addition, the level of antigenic proteins secreted by strain 9325 was higher than in ATCC 15305. This result was confirmed by Western blot analysis using anti-SsaA polyclonal antibodies, and no production or secretion of SsaA was detected in strain 7108. Moreover, when compared with the other strains that were analyzed, it was possible to detect higher levels of proteases secreted by strain 7108. The results reveal diversity in protein secretion among strains. This research is an important first step towards understanding the variability in S. saprophyticus and could be significant in explaining differences in virulence.
Project description:Characterization of a metagenomic regulatory sequence library derived from M. xanthus, E. coli, and O. urethralis genomes in strains expressing different RpoD ortholog variants. Targeted DNA and RNA seq used to profile relative DNA and RNA abundances, respectively of each regulatory sequence construct in the library.
Project description:Swine coronavirus-porcine epidemic diarrhea virus (PEDV) with specific susceptibility to pigs has existed for decades, and recurrent epidemics caused by mutant strains have swept the world again since 2010. Here, single-cell RNA-sequencing was used to perform a systematic analysis of pig small intestines infected with PEDV for the first time. Multiple cell types were identified by representative markers, including the unique marker DNAH11 of tuft cells. Meanwhile, the goblet and tuft cells were also susceptible to PEDV except enterocytes. PEDV infection obviously upregulated REG3G, which significantly inhibited virus replication. Notably, IFN-DELTAs in goblet and enterocyte progenitor cells were increased in virus infected piglet, and IFN-DELTA5 could induce GBP1, ISG15, OAS2 and IFITM1 dramatically raised in IPEC-J2 cells and restricted PEDV replication. Complement molecules were mainly expressed in intestinal cells excepting tuft cells, but PEDV decreased C3, C4A, and C5 in enterocytes, thus escaping the antiviral effect of C3. Finally, enterocytes expressed almost all coronavirus entry factors, and PEDV infection caused significant upregulation of the coronavirus receptor ACE2 in porcine enterocyte cells. In summary, this study systematically studied the response of different cell types in small intestine of pigs after PEDV infection, which deepened the understanding of viral pathogenesis.