scholarly journals hafeZ: Active prophage identification through read mapping

2021 ◽  
Author(s):  
Christopher J. R. Turkington ◽  
Neda Nezam Abadi ◽  
Robert A. Edwards ◽  
Juris A. Grasis

Bacteriophages that have integrated their genomes into bacterial chromosomes, termed prophages, are widespread across bacteria. Prophages are key components of bacterial genomes, with their integration often contributing novel, beneficial, characteristics to the infected host. Likewise, their induction—through the production and release of progeny virions into the surrounding environment—can have considerable ramifications on bacterial communities. Yet, not all prophages can excise following integration, due to genetic degradation by their host bacterium. Here, we present hafeZ, a tool able to identify 'active' prophages (i.e. those undergoing induction) within bacterial genomes through genomic read mapping. We demonstrate its use by applying hafeZ to publicly available sequencing data from bacterial genomes known to contain active prophages and show that hafeZ can accurately identify their presence and location in the host chromosomes. Availability and Implementation: hafeZ is implemented in Python 3.7 and freely available under an open-source GPL-3.0 license from https://github.com/Chrisjrt/hafeZ. Bugs and issues may be reported by submitting them via the hafeZ github issues page.

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Momchilo Vuyisich ◽  
Ayesha Arefin ◽  
Karen Davenport ◽  
Shihai Feng ◽  
Cheryl Gleasner ◽  
...  

Sequencing bacterial genomes has traditionally required large amounts of genomic DNA (~1 μg). There have been few studies to determine the effects of the input DNA amount or library preparation method on the quality of sequencing data. Several new commercially available library preparation methods enable shotgun sequencing from as little as 1 ng of input DNA. In this study, we evaluated the NEBNext Ultra library preparation reagents for sequencing bacterial genomes. We have evaluated the utility of NEBNext Ultra for resequencing andde novoassembly of four bacterial genomes and compared its performance with the TruSeq library preparation kit. The NEBNext Ultra reagents enable high quality resequencing andde novoassembly of a variety of bacterial genomes when using 100 ng of input genomic DNA. For the two most challenging genomes (Burkholderiaspp.), which have the highest GC content and are the longest, we also show that the quality of both resequencing andde novoassembly is not decreased when only 10 ng of input genomic DNA is used.


2021 ◽  
Author(s):  
Antonino Malacrino'

Microorganisms have an enormous impact on most of the life that inhabits our planet. Insects are an excellent example, as research showed that several microbial species are essential for insect nutrition, reproduction, fitness, defence and many other functions. More recently, we assisted to an exponential growth of studies describing the taxonomical composition of bacterial communities across insects' phylogeny. However, there is still an outstanding question that needs to be answered: which factors contribute most in shaping insects' microbiomes? This study tries to find an answer to this question by taking advantage of publicly available sequencing data and reanalysing over 4,000 samples of insect-associated bacterial communities under a common framework. Results suggest that insect taxonomy has a wider impact on the structure and diversity of their associated microbial communities than the other factors considered (diet, sex, life stage, sample origin and treatment). Also, a survey of the literature highlights several methodological limitations that needs to be considered in future research endeavours. This study proofs the amount of collective effort that lead to the current understanding of insect-microbiota interactions and their influence on insect biology, ecology and evolution with potential impact on insect conservation and management practices.


2018 ◽  
Author(s):  
Tommi Mäklin ◽  
Teemu Kallonen ◽  
Sophia David ◽  
Christine J. Boinett ◽  
Ben Pascoe ◽  
...  

AbstractDetermining the composition of bacterial communities beyond the level of a genus or species is challenging because of the considerable overlap between genomes representing close relatives. Here, we present the mSWEEP method for identifying and estimating the relative abundances of bacterial lineages from plate sweeps of enrichment cultures. mSWEEP leverages biologically grouped sequence assembly databases, applying probabilistic modelling, and provides controls for false positive results. Using sequencing data from major pathogens, we demonstrate significant improvements in lineage quantification and detection accuracy. Our method facilitates investigating cultures comprising mixtures of bacteria, and opens up a new field of plate sweep metagenomics.


2020 ◽  
Vol 36 (20) ◽  
pp. 5115-5116 ◽  
Author(s):  
August E Woerner ◽  
Jennifer Churchill Cihlar ◽  
Utpal Smart ◽  
Bruce Budowle

Abstract Motivation Assays in mitochondrial genomics rely on accurate read mapping and variant calling. However, there are known and unknown nuclear paralogs that have fundamentally different genetic properties than that of the mitochondrial genome. Such paralogs complicate the interpretation of mitochondrial genome data and confound variant calling. Results Remove the Numts! (RtN!) was developed to categorize reads from massively parallel sequencing data not based on the expected properties and sequence identities of paralogous nuclear encoded mitochondrial sequences, but instead using sequence similarity to a large database of publicly available mitochondrial genomes. RtN! removes low-level sequencing noise and mitochondrial paralogs while not impacting variant calling, while competing methods were shown to remove true variants from mitochondrial mixtures. Availability and implementation https://github.com/Ahhgust/RtN Supplementary information Supplementary data are available at Bioinformatics online.


2020 ◽  
Vol 10 ◽  
Author(s):  
Sateesh Peri ◽  
Sarah Roberts ◽  
Isabella R. Kreko ◽  
Lauren B. McHan ◽  
Alexandra Naron ◽  
...  

2012 ◽  
Vol 279 (1743) ◽  
pp. 3706-3715 ◽  
Author(s):  
Daniel J. Rankin ◽  
Leighton A. Turner ◽  
Jack A. Heinemann ◽  
Sam P. Brown

Bacterial genomes commonly contain ‘addiction’ gene complexes that code for both a toxin and a corresponding antitoxin. As long as both genes are expressed, cells carrying the complex can remain healthy. However, loss of the complex (including segregational loss in daughter cells) can entail death of the cell. We develop a theoretical model to explore a number of evolutionary puzzles posed by toxin–antitoxin (TA) population biology. We first extend earlier results demonstrating that TA complexes can spread on plasmids, as an adaptation to plasmid competition in spatially structured environments, and highlight the role of kin selection. We then considered the emergence of TA complexes on plasmids from previously unlinked toxin and antitoxin genes. We find that one of these traits must offer at least initially a direct advantage in some but not all environments encountered by the evolving plasmid population. Finally, our study predicts non-transitive ‘rock-paper-scissors’ dynamics to be a feature of intragenomic conflict mediated by TA complexes. Intragenomic conflict could be sufficient to select deleterious genes on chromosomes and helps to explain the previously perplexing observation that many TA genes are found on bacterial chromosomes.


2020 ◽  
Vol 96 (10) ◽  
Author(s):  
Josep Ramoneda ◽  
Johannes J Le Roux ◽  
Emmanuel Frossard ◽  
Beat Frey ◽  
Hannes Andres Gamper

ABSTRACT There is interest in understanding how cultivation, plant genotype, climate and soil conditions influence the biogeography of root nodule bacterial communities of legumes. For crops from regions with relict wild populations, this is of even greater interest because the effects of cultivation on symbiont communities can be revealed, which is of particular interest for bacteria such as rhizobia. Here, we determined the structure of root nodule bacterial communities of rooibos (Aspalathus linearis), a leguminous shrub endemic to South Africa. We related the community dissimilarities of the root nodule bacteria of 18 paired cultivated and wild rooibos populations to pairwise geographical distances, plant ecophysiological characteristics and soil physicochemical parameters. Using next-generation sequencing data, we identified region-, cultivation- and farm-specific operational taxonomic units for four distinct classes of root nodule bacterial communities, dominated by members of the genus Mesorhizobium. We found that while bacterial richness was locally increased by organic cultivation, strong biogeographical differentiation in the bacterial communities of wild rooibos disappeared with cultivation of one single cultivar across its entire cultivation range. This implies that expanding rooibos farming has the potential to endanger wild rooibos populations through the homogenisation of root nodule bacterial diversity.


mSystems ◽  
2016 ◽  
Vol 1 (6) ◽  
Author(s):  
Aaron Weimann ◽  
Kyra Mooren ◽  
Jeremy Frank ◽  
Phillip B. Pope ◽  
Andreas Bremges ◽  
...  

ABSTRACT Bacteria are ubiquitous in our ecosystem and have a major impact on human health, e.g., by supporting digestion in the human gut. Bacterial communities can also aid in biotechnological processes such as wastewater treatment or decontamination of polluted soils. Diverse bacteria contribute with their unique capabilities to the functioning of such ecosystems, but lab experiments to investigate those capabilities are labor-intensive. Major advances in sequencing techniques open up the opportunity to study bacteria by their genome sequences. For this purpose, we have developed Traitar, software that predicts traits of bacteria on the basis of their genomes. It is applicable to studies with tens or hundreds of bacterial genomes. Traitar may help researchers in microbiology to pinpoint the traits of interest, reducing the amount of wet lab work required. The number of sequenced genomes is growing exponentially, profoundly shifting the bottleneck from data generation to genome interpretation. Traits are often used to characterize and distinguish bacteria and are likely a driving factor in microbial community composition, yet little is known about the traits of most microbes. We describe Traitar, the microbial trait analyzer, which is a fully automated software package for deriving phenotypes from a genome sequence. Traitar provides phenotype classifiers to predict 67 traits related to the use of various substrates as carbon and energy sources, oxygen requirement, morphology, antibiotic susceptibility, proteolysis, and enzymatic activities. Furthermore, it suggests protein families associated with the presence of particular phenotypes. Our method uses L1-regularized L2-loss support vector machines for phenotype assignments based on phyletic patterns of protein families and their evolutionary histories across a diverse set of microbial species. We demonstrate reliable phenotype assignment for Traitar to bacterial genomes from 572 species of eight phyla, also based on incomplete single-cell genomes and simulated draft genomes. We also showcase its application in metagenomics by verifying and complementing a manual metabolic reconstruction of two novel Clostridiales species based on draft genomes recovered from commercial biogas reactors. Traitar is available at https://github.com/hzi-bifo/traitar . IMPORTANCE Bacteria are ubiquitous in our ecosystem and have a major impact on human health, e.g., by supporting digestion in the human gut. Bacterial communities can also aid in biotechnological processes such as wastewater treatment or decontamination of polluted soils. Diverse bacteria contribute with their unique capabilities to the functioning of such ecosystems, but lab experiments to investigate those capabilities are labor-intensive. Major advances in sequencing techniques open up the opportunity to study bacteria by their genome sequences. For this purpose, we have developed Traitar, software that predicts traits of bacteria on the basis of their genomes. It is applicable to studies with tens or hundreds of bacterial genomes. Traitar may help researchers in microbiology to pinpoint the traits of interest, reducing the amount of wet lab work required.


Genes ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1739
Author(s):  
Tunde I. Huszar ◽  
Katherine B. Gettings ◽  
Peter M. Vallone

The top challenges of adopting new methods to forensic DNA analysis in routine laboratories are often the capital investment and the expertise required to implement and validate such methods locally. In the case of next-generation sequencing, in the last decade, several specifically forensic commercial options became available, offering reliable and validated solutions. Despite this, the readily available expertise to analyze, interpret and understand such data is still perceived to be lagging behind. This review gives an introductory overview for the forensic scientists who are at the beginning of their journey with implementing next-generation sequencing locally and because most in the field do not have a bioinformatics background may find it difficult to navigate the new terms and analysis options available. The currently available open-source and commercial software for forensic sequencing data analysis are summarized here to provide an accessible starting point for those fairly new to the forensic application of massively parallel sequencing.


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