The implementation of routine whole-genome sequencing (WGS) promises to transform our ability to monitor the emergence and spread of bacterial pathogens. Here we combined WGS data from 308 invasive Staphylococcus aureus isolates corresponding to a pan-European population snapshot, with epidemiological and resistance data. Geospatial visualization of the data is made possible by a generic software tool designed for public health purposes that is available at the project URL (http://www.microreact ...[more]
Project description:Abstract Staphylococcus aureus of sequence type 398 has emerged in Europe, North America and Asia and has typically been associated with livestock and their human contacts. We analysed two PVL-negative t034-ST398 isolates from humans in contact with pigs, and two t034-ST398 PVL-positive isolates from two unrelated adopted Chinese children using multi-strain microarrays to determine the genomic variability. The ST398 isolates clearly belong to the same lineage when compared to other clonal lineages. However, the four isolates cluster into two distinct groups corresponding to differences in epidemiology based on mobile genetic elements and resistance patterns, suggesting the two groups are epidemiologically distinct. Data is also available from http://bugs.sgul.ac.uk/E-BUGS-84
Project description:ZIKV strains belong to three phylogenetic lineages: East African, West African, and Asian/American. RNA virus genomes exist as populations of genetically-related sequences whose heterogeneity may impact viral fitness, evolution, and virulence. The genetic diversity of representative ZIKVs (N=7) from each lineage was examined using next generation sequencing (NGS) paired with downstream Shannon entropy calculation and single nucleotide variant (SNV) analysis. This comprehensive analysis of ZIKV genetic diversity provides insight into the genetic diversity of ZKIV and repository of SNV positions across lineages.
Project description:With the advent of advanced sequencing technology, studies of RNA viruses have shown that genetic diversity contribute to both attenuation and virulence. The differences in genetic diversity of wild-type Asibi virus and 17D-204 vaccine provides an unique opportunity to investigate RNA population theory in the context of a well described live attenuated vaccine. Utilizing infectious clone-derived viruses containing some of the amino acid substitutions that differentiate yellow fever wild-type Asibi strain from 17D vaccine and recovered in a controlled experiment, establishes that the genetic diversity differences that exist between wild-type Asibi and 17D-204 vaccine viruses are not influenced by either different passage history or source of samples, but rather resulted from the attenuation of wild-type Asibi virus to yield the 17D vaccine sub-strains.
Project description:Understanding how DNA sequence variation is translated into variation for complex phenotypes has remained elusive, but is essential for predicting adaptive evolution, selecting agriculturally important animals and crops, and personalized medicine. Here, we quantified genome-wide genetic variation in gene expression in the sequenced inbred lines of the Drosophila melanogaster Genetic Reference Panel. We found that a substantial fraction of the Drosophila transcriptome is genetically variable and organized into modules of genetically correlated transcripts, which provide functional context for newly identified novel transcribed regions. We identified regulatory variants for the mean and variance of gene expression, both of which showed oligogenic genetic architecture. Expression quantitative trait loci the mean, but not the variance, of gene expression were concentrated near genes. This comprehensive characterization of transcriptomic diversity and its genetic basis in the DGRP is critically important for a systems understanding of quantitative trait variation.
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