Anemones of the genus Actinia are ecologically important and familiar organisms on many rocky shores. However, this genus is taxonomically problematical and prior evidence suggests that the North Atlantic beadlet anemone, Actinia equina, may actually consist of a number of cryptic species. Previous genetic work has been largely limited to allozyme electrophoresis and there remains a dearth of genetic resources with which to study this genus. Mitochondrial DNA sequencing may help to clarify the taxonomy of Actinia. Here, the complete mitochondrial genome of the beadlet anemone Actinia equina (Cnidaria: Anthozoa: Actinaria: Actiniidae) is shown to be 20,690?bp in length and…
Salmonella Typhimurium sequence type (ST) 313 causes invasive nontyphoidal Salmonella (iNTS) disease in sub-Saharan Africa, targeting susceptible HIV+, malarial, or malnourished individuals. An in-depth genomic comparison between the ST313 isolate D23580 and the well-characterized ST19 isolate 4/74 that causes gastroenteritis across the globe revealed extensive synteny. To understand how the 856 nucleotide variations generated phenotypic differences, we devised a large-scale experimental approach that involved the global gene expression analysis of strains D23580 and 4/74 grown in 16 infection-relevant growth conditions. Comparison of transcriptional patterns identified virulence and metabolic genes that were differentially expressed between D23580 versus 4/74, many of which…
The bacterial genus Staphylococcus comprises diverse species with most being described as colonizers of human and animal skin. A relational analysis of features that discriminate its species and contribute to niche adaptation and survival remains to be fully described. In this study, an interspecies, whole-genome comparative analysis of 21 Staphylococcus species was performed based on their orthologues. Three well-defined multi-species groups were identified: group A (including aureus/epidermidis); group B (including saprophyticus/xylosus) and group C (including pseudintermedius/delphini). The machine learning algorithm Random Forest was applied to prioritize orthologs that drive formation of the Staphylococcus species groups A-C. Orthologues driving staphylococcal intrageneric…
Aedes aegypti is the principal vector of several important arboviruses. Among the methods of vector control to limit transmission of disease are genetic strategies that involve the release of sterile or genetically modified non-biting males, which has generated interest in manipulating mosquito sex ratios. Sex determination in Ae. aegypti is controlled by a non-recombining Y chromosome-like region called the M locus, yet characterisation of this locus has been thwarted by the repetitive nature of the genome. In 2015, an M locus gene named Nix was identified that displays the qualities of a sex determination switch.With the use of a whole-genome…
African trypanosomiasis is a vector-borne disease of humans and livestock caused by African trypanosomes (Trypanosoma spp.). Survival in the vertebrate bloodstream depends on antigenic variation of Variant Surface Glycoproteins (VSGs) coating the parasite surface. In T. brucei, a model for antigenic variation, monoallelic VSG expression originates from dedicated VSG expression sites (VES). Trypanosoma brucei VES have a conserved structure consisting of a telomeric VSG locus downstream of unique, repeat sequences, and an independent promoter. Additional protein-coding sequences, known as "Expression Site Associated Genes (ESAGs)", are also often present and are implicated in diverse, bloodstream-stage functions. Trypanosoma congolense is a related…
Pseudomonas aeruginosa colonises the upper airway of cystic fibrosis (CF) patients, providing a reservoir of host-adapted genotypes that subsequently establish chronic lung infection. We previously experimentally-evolved P. aeruginosa in a murine model of respiratory tract infection and observed early-acquired mutations in pmrB, encoding the sensor kinase of a two-component system that promoted establishment and persistence of infection. Here, using proteomics, we show downregulation of proteins involved in LPS biosynthesis, antimicrobial resistance and phenazine production in pmrB mutants, and upregulation of proteins involved in adherence, lysozyme resistance and inhibition of the chloride ion channel CFTR, relative to wild-type strain LESB65. Accordingly,…
As species diverge, so does their transposable element (TE) content. Within a genome, TE families may eventually become dormant due to host-silencing mechanisms, natural selection and the accumulation of inactive copies. The transmission of active copies from a TE families, both vertically and horizontally between species, can allow TEs to escape inactivation if it occurs often enough, as it may allow TEs to temporarily escape silencing in a new host. Thus, the contribution of horizontal exchange to TE persistence has been of increasing interest.Here, we annotated TEs in five species with sequenced genomes from the D. pseudoobscura species group, and…
In recent years, an increasing number of Campylobacter species have been associated with human gastrointestinal (GI) diseases including gastroenteritis, inflammatory bowel disease, and colorectal cancer. Campylobacter concisus, an oral commensal historically linked to gingivitis and periodontitis, has been increasingly detected in the lower GI tract. In the present study, we generated robust genome sequence data from C. concisus strains and undertook a comprehensive pangenome assessment to identify C. concisus virulence properties and to explain potential adaptations acquired while residing in specific ecological niche(s) of the GI tract. Genomes of 53 new C. concisus strains were sequenced, assembled, and annotated including…
Ochrobactrum haematophilum FI11154 was isolated from kunu-zaki, a Nigerian traditional fermented millet-based food. Here, we present the first complete genome sequence of this species. The genome consists of five replicons and contains genes related to iron uptake and phosphatase activities. Copyright © 2018 Diaz et al.
Decline-diseases are complex and becoming increasingly problematic to tree health globally. Acute Oak Decline (AOD) is characterized by necrotic stem lesions and galleries of the bark-boring beetle, Agrilus biguttatus, and represents a serious threat to oak. Although multiple novel bacterial species and Agrilus galleries are associated with AOD lesions, the causative agent(s) are unknown. The AOD pathosystem therefore provides an ideal model for a systems-based research approach to address our hypothesis that AOD lesions are caused by a polymicrobial complex. Here we show that three bacterial species, Brenneria goodwinii, Gibbsiella quercinecans and Rahnella victoriana, are consistently abundant in the lesion…
The ST313 sequence type of Salmonella Typhimurium causes invasive non-typhoidal salmonellosis and was thought to be confined to sub-Saharan Africa. Two distinct phylogenetic lineages of African ST313 have been identified.We analysed the whole genome sequences of S. Typhimurium isolates from UK patients that were generated following the introduction of routine whole-genome sequencing (WGS) of Salmonella enterica by Public Health England in 2014.We found that 2.7% (84/3147) of S. Typhimurium from patients in England and Wales were ST313 and were associated with gastrointestinal infection. Phylogenetic analysis revealed novel diversity of ST313 that distinguished UK-linked gastrointestinal isolates from African-associated extra-intestinal isolates. The…
The majority of bacterial genomes have high coding efficiencies, but there are some genomes of intracellular bacteria that have low gene density. The genome of the endosymbiont Sodalis glossinidius contains almost 50% pseudogenes containing mutations that putatively silence them at the genomic level. We have applied multiple omic strategies, combining: Illumina and Pacific Biosciences Single-Molecule Real Time DNA-sequencing and annotation; stranded RNA-sequencing; and proteome analysis to better understand the transcriptional and translational landscape of Sodalis pseudogenes, and potential mechanisms for their control. Between 53% and 74% of the Sodalis transcriptome remains active in cell-free culture. Mean sense transcription from Coding…
Current DNA assembly methods are prone to sequence errors, requiring rigorous quality control (QC) to identify incorrect assemblies or synthesized constructs. Such errors can lead to misinterpretation of phenotypes. Because of this intrinsic problem, routine QC analysis is generally performed on three or more clones using a combination of restriction endonuclease assays, colony PCR, and Sanger sequencing. However, as new automation methods emerge that enable high-throughput assembly, QC using these techniques has become a major bottleneck. Here, we describe a quick and affordable methodology for the QC of synthetic constructs. Our method involves a one-pot digestion-ligation DNA assembly reaction, based…
We report here the first whole-genome sequence of a skin-associated strain of Staphylococcus hominis determined using the PacBio long-read sequencing platform. S. hominis is a major commensal of the skin microflora. This genome sequence adds to our understanding of this species and will aid studies of gene traffic between staphylococci. Copyright © 2017 Coates-Brown and Horsburgh.
How the pathogen Clostridium difficile might survive, evolve and be transferred between reservoirs within the natural environment is poorly understood. Some ribotypes are found both in clinical and environmental settings. Whether these strains are distinct from each another and evolve in the specific environments is not established. The possession of a highly mobile genome has contributed to the genetic diversity and ongoing evolution of C. difficile. Interpretations of genetic diversity have been limited by fragmented assemblies resulting from short-read length sequencing approaches and by a limited understanding of epigenetic regulation of diversity. To address this, single molecule real time (SMRT) sequencing…