Project description:Escherichia coli strain C is the last of five E. coli strains (C, K12, B, W, Crooks) designated as safe for laboratory purposes whose genome has not been sequenced. We found that E. coli C forms more robust biofilms than the other four laboratory strains. Here we present the complete genomic sequence of this strain in which we utilized high resolution optical mapping to confirm a large inversion in comparison to other strains. DNA sequence comparison revealed the absence of several genes involved in biofilm formation, such as antigen 43, waaSBOJYZUL for LPS synthesis, and cpsB for curli synthesis. The main difference affecting biofilm formation is the presence of an IS3-like insertion sequence in front of the carbon storage regulator csrA gene. This insertion is located 86 bp upstream of the csrA start codon inside the -35 region of P4 promoter and blocks the transcription from the sigma32 and sigma70 promoters P1-P3 located further upstream. Analysis of gene expression profiles in planktonic and biofilm attached cells by the RNAseq method allows better understanding of this regulatory pathway in E. coli.
Project description:Background: The human pathogen Arcobacter butzleri is a member of the epsilon subdivision of the Proteobacteria and a close taxonomic relative of other established pathogens, such as Campylobacter jejuni and Helicobacter pylori. Here we present the complete genome sequence of the human clinical isolate, A. butzleri strain RM4018. Results: Arcobacter butzleri is a member of the Campylobacteraceae, but the majority of its proteome is most similar to those of Thiomicrospira denitrificans and Wolinella succinogenes, both members of the Helicobacteraceae. In addition, many of the genes and pathways described here, e.g. those involved in signal transduction and sulfur metabolism, have been identified previously within the epsilon subdivision only in T. denitrificans and/or W. succinogenes, or are unique to the subdivision. The analyses indicated also that a large proportion of the A. butzleri genome is devoted to growth and survival under diverse environmental conditions, with a large number of respiration-associated proteins, signal transduction and chemotaxis proteins and proteins involved in DNA repair and adaptation. To investigate the genomic diversity of A. butzleri strains, we constructed an A. butzleri DNA microarray comprising 2238 genes from strain RM4018. Comparative genomic indexing analysis of 12 additional A. butzleri strains identified both the core genes of A. butzleri and intraspecies hypervariable regions, where < 70% of the genes were present in at least two strains. Conclusion: The presence of environmentally-associated pathways and loci, as well as genes associated with virulence indicates that this free-living, water-borne organism A. butzleri can be classified rightfully as an emerging pathogen. Keywords: comparative genomic hybridization
Project description:The skin commensal yeast Malassezia is associated with several skin disorders. To establish a reference resource, we sought to determine the complete genome sequence of Malassezia sympodialis and identify its protein-coding genes. A novel genome annotation workflow combining RNA sequencing, proteomics, and manual curation was developed to determine gene structures with high accuracy.
Project description:The Periconia genus belongs to the phylum Ascomycota, order Pleosporales, family Periconiaceae. Periconia is widespread in many habitats but little is known about its ecology. Several species produce bioactive molecules, among them, Periconia digitata extracts were shown to be deadly active against the pine wilt nematode. The strain CNCM I-4278, here identified as P. digitata was able to inhibit the plant pathogen Phytophthora parasitica. Since P. digitata has great potential as biocontrol agent and the only other genome available in the Periconiaceae family is that of Periconia macrospinosa, which is quite fragmentary, we generated long-read genomic data for P. digitata. Thanks to the PacBio Hifi sequencing technology, we obtained a high-quality genome with a total length of 38,967,494 bp, represented by 13 haploid chromosomes. The transcriptomic and proteomic data strengthen and support the genome annotation. Besides representing a new reference genome within the Periconiaceae, this work will also contribute in our understanding of the Eukaryotic tree of life. Not least, opens new possibilities to the biotechnological use of the species.
