BLASTPLOT: a PERL module to plot next generation sequencing NCBI-BLAST results

BACKGROUND: The development of Next Generation Sequencing (NGS) during the last decade has created an unprecedented amount of sequencing data, as well as the ability to rapidly sequence specimens of interest. Read-based BLAST analysis of NGS data is a common procedure especially in the case of metagenomic samples. However, coverage is usually not enough to allow for de novo assembly. This type of read-based analysis often creates the question of how the reads that align to the same sequence are distributed. The same question applies to preparation of primers or probes for microarray experiments. Although there are several packages that allow the visualization of DNA segments in relation to a reference, in most cases they require the visualization of one reference at a time and the capture of screen shots for each segment. Such a procedure could be tedious and time consuming. The field is in need of a solution that automates the capture of coverage plots for all the segments of interest. RESULTS: We have created BLASTPLOT, a PERL module to quickly plot the BLAST results from short sequences (primers, probes, reads) against reference targets. CONCLUSIONS: BLASTPLOT is a simple to use PERL module that allows the generation of PNG graphs for all the reference sequences associated with a BLAST result set

Crystal Structure of the Hendra Virus Attachment G Glycoprotein Bound to a Potent Cross-Reactive Neutralizing Human Monoclonal Antibody

The henipaviruses, represented by Hendra (HeV) and Nipah (NiV) viruses are highly pathogenic zoonotic paramyxoviruses with uniquely broad host tropisms responsible for repeated outbreaks in Australia, Southeast Asia, India and Bangladesh. The high morbidity and mortality rates associated with infection and lack of licensed antiviral therapies make the henipaviruses a potential biological threat to humans and livestock. Henipavirus entry is initiated by the attachment of the G envelope glycoprotein to host cell membrane receptors. Previously, henipavirus-neutralizing human monoclonal antibodies (hmAb) have been isolated using the HeV-G glycoprotein and a human naïve antibody library. One cross-reactive and receptor-blocking hmAb (m102.4) was recently demonstrated to be an effective post-exposure therapy in two animal models of NiV and HeV infection, has been used in several people on a compassionate use basis, and is currently in development for use in humans. Here, we report the crystal structure of the complex of HeV-G with m102.3, an m102.4 derivative, and describe NiV and HeV escape mutants. This structure provides detailed insight into the mechanism of HeV and NiV neutralization by m102.4, and serves as a blueprint for further optimization of m102.4 as a therapeutic agent and for the development of entry inhibitors and vaccines

Bioinformatic Characterization of Mosquito Viromes within the Eastern United States and Puerto Rico: Discovery of Novel Viruses

Mosquitoes are efficient, militarily relevant vectors of infectious disease pathogens, including many RNA viruses. The vast majority of all viruses are thought to be undiscovered. Accordingly, recent studies have shown that viruses discovered in insects are very divergent from known pathogens and that many of them lack appropriate reference sequences in the public databases. Given that the majority of viruses are likely still undiscovered, environmental sampling stands to provide much needed reference samples as well as genetic sequences for comparison. In this study, we sought to determine whether samples of mosquitoes collected from different sites (the Caribbean and locations on the US East Coast) could be differentiated using metagenomic analysis of the RNA viral fraction. We report here distinct virome profiles, even from samples collected short distances apart. In addition to profiling the previously known viruses from these samples, we detected a number of viruses that have been previously undiscovered

Reclassification of Wolbachia persica as Francisella persica comb. nov and emended description of the family Francisellaceae

The taxonomic status of the bacterium Wolbachia persica is described, and based on the evidence presented, transfer of this species to the genus Francisella as Francisella persica comb. nov. is proposed. This reclassification is supported by data generated from genomic comparisons of W. persica ATCC VR-331(T) (=FSC845(T)=DSM 101678(T)) to other near neighbours, including Francisella tularensis subsp. novicida. The full-length 16S rRNA gene sequence of strain ATCC VR-331(T) had 98.5 % nucleotide identity to the cognate gene in F. tularensis, with the highest similarity to subspecies novicida. Phylogenetic trees of full-length 16S rRNA gene, gyrA and recA sequences from species of the genera Wolbachia (class Alphaproteobacteria) and Francisella (class Gammaproteobacteria) indicated that W. persica ATCC VR-331(T) was most closely related to members of the genus Francisella and not Wolbachia. Local collinear blocks within the chromosome of strain ATCC VR-331(T) had considerable similarity with F. tularensis subsp. novicida, but not with any Wolbachia strain. The genomes of strain ATCC VR-331(T) and F. tularensis subsp. novicida Utah 112(T) (=ATCC 15482(T)) contained an average nucleotide identity mean of 88.72 % and median of 89.18 %. Importantly, the genome of strain ATCC VR-331(T) contained one Francisella Pathogenicity Island, similar to F. tularensis subsp. novicida, as well as the Francisella-specific gene fopA1 and F. tularensis-specific genes fopA2 and lpnA (also referred to as tul4). In contrast to the obligate intracellular genus Wolbachia, strain ATCC VR-331(T) and facultative intracellular Francisella can replicate in specialized cell-free media. Collectively, these results demonstrate that Wolbachia persica should be reclassified in the genus Francisella as Francisella persica comb. nov. The type strain of Francisella persica comb. nov. is ATCC VR-331(T) (=FSC845(T)=DSM 101678(T)). An emended description of the family Francisellaceae is also provided

Scanning the Landscape of Genome Architecture of Non-O1 and Non-O139 <i>Vibrio cholerae</i> by Whole Genome Mapping Reveals Extensive Population Genetic Diversity

<div><p>Historically, cholera outbreaks have been linked to <i>V</i>. <i>cholerae</i> O1 serogroup strains or its derivatives of the O37 and O139 serogroups. A genomic study on the 2010 Haiti cholera outbreak strains highlighted the putative role of non O1/non-O139 <i>V</i>. <i>cholerae</i> in causing cholera and the lack of genomic sequences of such strains from around the world. Here we address these gaps by scanning a global collection of <i>V</i>. <i>cholerae</i> strains as a first step towards understanding the population genetic diversity and epidemic potential of non O1/non-O139 strains. Whole Genome Mapping (Optical Mapping) based bar coding produces a high resolution, ordered restriction map, depicting a complete view of the unique chromosomal architecture of an organism. To assess the genomic diversity of non-O1/non-O139 <i>V</i>. <i>cholerae</i>, we applied a Whole Genome Mapping strategy on a well-defined and geographically and temporally diverse strain collection, the Sakazaki serogroup type strains. Whole Genome Map data on 91 of the 206 serogroup type strains support the hypothesis that <i>V</i>. <i>cholerae</i> has an unprecedented genetic and genomic structural diversity. Interestingly, we discovered chromosomal fusions in two unusual strains that possess a single chromosome instead of the two chromosomes usually found in <i>V</i>. <i>cholerae</i>. We also found pervasive chromosomal rearrangements such as duplications and indels in many strains. The majority of <i>Vibrio</i> genome sequences currently in public databases are unfinished draft sequences. The Whole Genome Mapping approach presented here enables rapid screening of large strain collections to capture genomic complexities that would not have been otherwise revealed by unfinished draft genome sequencing and thus aids in assembling and finishing draft sequences of complex genomes. Furthermore, Whole Genome Mapping allows for prediction of novel <i>V</i>. <i>cholerae</i> non-O1/non-O139 strains that may have the potential to cause future cholera outbreaks.</p></div

UPGMA method based dendrograms of Sakazaki serogroup strains.

<p>Whole Genome Mapping data based distance matrix with default parameters was used to generate the dendrograms. The three clusters (epidemic <i>V</i>. <i>cholerae</i> Classical and El Tor, one group of environmental isolates from rat, and <i>V</i>. <i>mimicus</i>) are indicated on the branches. The distribution of VPI and CTX on chromosome I in non-O1/non-O139 strains are indicated as well. The different colors of the highlighted strains indicate the following characteristics: No highlight- Clinical; Gray-environmental; Light green (serogroups O2-O4) source unknown; Yellow: epidemic O1 Classical and El Tor; Green: non-O1 epidemic strains; Pink: <i>V</i>. <i>mimicus</i>; Blue: One <i>V</i>. <i>mimicus</i> isolate (serogroup O115) that has the VPI cluster; Orange: Clinical and carry both VPI and CTX clusters; Light red (O77, O49, O80, O53): Clinical and carry VPI only. Scale: 0.2 = 20% dissimilarity.</p

Pulse field gel electrophoresis of chromosomal DNAs of <i>V</i>. <i>cholerae</i> 1154–74 (O49) and 10432–62 (O27) strains.

<p>PFGE of intact <i>V</i>. <i>cholerae</i> DNA isolated from different <i>V</i>. <i>cholerae</i> strains. Lanes from left to right: 1) Molecular weight marker (Mbases) <i>H</i>. <i>wingeii</i> chromosomes, 2) <i>V</i>. <i>cholerae</i> O1 N16961 (the bands corresponding to Chr I and Chr II are marked by an asterisk), 3) <i>V</i>. <i>cholerae</i> 10432–62 (O27) and 4) <i>V</i>. <i>cholerae</i> 1154–74 (O49). In lanes 3 and 4, the band corresponding to the single chromosome is marked by a triangle.</p

Strain collection features of the Sakazaki serogroup set.

<p>A) Breakdown of strains based on geographical location (country where the strains were isolated). B) Breakdown of strains based on isolation source. The number of strains for which Whole Genome Maps were generated in this study is indicated in parentheses.</p