Genome Analysis of the Enterococcus faecium Entfac.YE Prophage

Author(s):  
Yara Elahi ◽  
Ramin Mazaheri Nezhad Fard ◽  
Arash Seifi ◽  
Saeideh Mahfouzi ◽  
Ali Akbar Saboor Yaraghi

Background: Bacteriophages are viruses that infect bacteria. Bacteriophages are widely distributed in various environments. The prevalence of bacteriophages in water sources, especially wastewaters, is naturally high. These viruses affect evolution of most bacterial species. Bacteriophages are able to integrate their genomes into the chromosomes of their hosts as prophages and hence transfer resistance genes to the bacterial genomes. Enterococci are commensal bacteria that show high resistance to common antibiotics. For example, prevalence of vancomycin-resistant enterococci has increased within the last decades. Methods: Enterococcal isolates were isolated from clinical samples and morphological, phenotypical, biochemical, and molecular methods were used to identify and confirm their identity. Bacteriophages extracted from water sources were then applied to isolated Enterococcus faecium (E. faecium). In the next step, the bacterial genome was completely sequenced and the existing prophage genome in the bacterial genome was analyzed. Results: In this study, E. faecium EntfacYE was isolated from a clinical sample. The EntfacYE genome was analyzed and 88 prophage genes were identified. The prophage content included four housekeeping genes, 29 genes in the group of genes related to replication and regulation, 25 genes in the group of genes related to structure and packaging, and four genes belonging to the group of genes associated with lysis. Moreover, 26 genes were identified with unknown functions. Conclusion: In conclusion, genome analysis of prophages can lead to a better understanding of their roles in the rapid evolution of bacteria.

mSystems ◽  
2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Robert A. Petit ◽  
Timothy D. Read

ABSTRACT Sequencing of bacterial genomes using Illumina technology has become such a standard procedure that often data are generated faster than can be conveniently analyzed. We created a new series of pipelines called Bactopia, built using Nextflow workflow software, to provide efficient comparative genomic analyses for bacterial species or genera. Bactopia consists of a data set setup step (Bactopia Data Sets [BaDs]), which creates a series of customizable data sets for the species of interest, the Bactopia Analysis Pipeline (BaAP), which performs quality control, genome assembly, and several other functions based on the available data sets and outputs the processed data to a structured directory format, and a series of Bactopia Tools (BaTs) that perform specific postprocessing on some or all of the processed data. BaTs include pan-genome analysis, computing average nucleotide identity between samples, extracting and profiling the 16S genes, and taxonomic classification using highly conserved genes. It is expected that the number of BaTs will increase to fill specific applications in the future. As a demonstration, we performed an analysis of 1,664 public Lactobacillus genomes, focusing on Lactobacillus crispatus, a species that is a common part of the human vaginal microbiome. Bactopia is an open source system that can scale from projects as small as one bacterial genome to ones including thousands of genomes and that allows for great flexibility in choosing comparison data sets and options for downstream analysis. Bactopia code can be accessed at https://www.github.com/bactopia/bactopia. IMPORTANCE It is now relatively easy to obtain a high-quality draft genome sequence of a bacterium, but bioinformatic analysis requires organization and optimization of multiple open source software tools. We present Bactopia, a pipeline for bacterial genome analysis, as an option for processing bacterial genome data. Bactopia also automates downloading of data from multiple public sources and species-specific customization. Because the pipeline is written in the Nextflow language, analyses can be scaled from individual genomes on a local computer to thousands of genomes using cloud resources. As a usage example, we processed 1,664 Lactobacillus genomes from public sources and used comparative analysis workflows (Bactopia Tools) to identify and analyze members of the L. crispatus species.


mBio ◽  
2014 ◽  
Vol 5 (6) ◽  
Author(s):  
Sophie M. Colston ◽  
Matthew S. Fullmer ◽  
Lidia Beka ◽  
Brigitte Lamy ◽  
J. Peter Gogarten ◽  
...  

ABSTRACTProkaryotic taxonomy is the underpinning of microbiology, as it provides a framework for the proper identification and naming of organisms. The “gold standard” of bacterial species delineation is the overall genome similarity determined by DNA-DNA hybridization (DDH), a technically rigorous yet sometimes variable method that may produce inconsistent results. Improvements in next-generation sequencing have resulted in an upsurge of bacterial genome sequences and bioinformatic tools that compare genomic data, such as average nucleotide identity (ANI), correlation of tetranucleotide frequencies, and the genome-to-genome distance calculator, orin silicoDDH (isDDH). Here, we evaluate ANI andisDDH in combination with phylogenetic studies usingAeromonas, a taxonomically challenging genus with many described species and several strains that were reassigned to different species as a test case. We generated improved, high-quality draft genome sequences for 33Aeromonasstrains and combined them with 23 publicly available genomes. ANI andisDDH distances were determined and compared to phylogenies from multilocus sequence analysis of housekeeping genes, ribosomal proteins, and expanded core genes. The expanded core phylogenetic analysis suggested relationships between distantAeromonasclades that were inconsistent with studies using fewer genes. ANI values of ≥96% andisDDH values of ≥70% consistently grouped genomes originating from strains of the same species together. Our study confirmed known misidentifications, validated the recent revisions in the nomenclature, and revealed that a number of genomes deposited in GenBank are misnamed. In addition, two strains were identified that may represent novelAeromonasspecies.IMPORTANCEImprovements in DNA sequencing technologies have resulted in the ability to generate large numbers of high-quality draft genomes and led to a dramatic increase in the number of publically available genomes. This has allowed researchers to characterize microorganisms using genome data. Advantages of genome sequence-based classification include data and computing programs that can be readily shared, facilitating the standardization of taxonomic methodology and resolving conflicting identifications by providing greater uniformity in an overall analysis. UsingAeromonasas a test case, we compared and validated different approaches. Based on our analyses, we recommend cutoff values for distance measures for identifying species. Accurate species classification is critical not only to obviate the perpetuation of errors in public databases but also to ensure the validity of inferences made on the relationships among species within a genus and proper identification in clinical and veterinary diagnostic laboratories.


2018 ◽  
Vol 34 (4) ◽  
pp. 229-237 ◽  
Author(s):  
Francesca Chiesi ◽  
Andrea Bonacchi ◽  
Caterina Primi ◽  
Alessandro Toccafondi ◽  
Guido Miccinesi

Abstract. The present study aimed at evaluating if the three-item sense of coherence (SOC) scale developed by Lundberg and Nystrom Peck (1995) can be effectively used for research purpose in both nonclinical and clinical samples. To provide evidence that it represents adequately the measured construct we tested its validity in a nonclinical (N = 658) and clinical sample (N = 764 patients with cancer). Results obtained in the nonclinical sample attested a positive relation of SOC – as measured by the three-item SOC scale – with Antonovsky’s 13-item and 29-item SOC scales (convergent validity), and with dispositional optimism, sense of mastery, anxiety, and depression symptoms (concurrent validity). Results obtained in the clinical sample confirmed the criterion validity of the scale attesting the positive role of SOC – as measured by the three-item SOC scale – on the person’s capacity to respond to illness and treatment. The current study provides evidence that the three-item SOC scale is a valid, low-loading, and time-saving instrument for research purposes on large sample.


2020 ◽  
Vol 26 (1-2) ◽  
pp. 73-78
Author(s):  
A Hossen ◽  
MH Rahman ◽  
MZ Ali ◽  
MA Yousuf ◽  
MZ Hassan ◽  
...  

Duck plague (DP) is the most important infectious disease of geese, ducks and free-ranging water birds. The present study was conducted to determine the prevalence of duck plague virus followed by isolation and identification. For these purposes, a total of 155 cloacal swabs samples were collected randomly from duck of different haor areas of Bangladesh including 45 (41 surveillance and 4 clinical) samples from Netrokona; 42 (40 surveillance and 2 clinical) samples from Kishoregonj; 30 samples from Brahmanbaria and 38 samples from Sunamganj. The samples were processed and pooled (1:5 ratio) for initial screening of target polymerase gene of duck plague virus by polymerase chain reaction (PCR) method. All the samples of a positive pool were then tested individually for identifying the individual positive samples. The result showed that out of 155 samples, 41 (26.45%) were found positive in which 17 were from Netrokona, where 15 (36.58%) were from surveillance samples and 2 (50%) were from clinical sample; 16 were from Kishoregonj, where 14 (35%) were from surveillance samples and 2 (100%) were from clinical sample; 2 (6.6%) were from Brahmanbaria and 5 (13.15%) were from Sunamganj. These positive samples were inoculated into 9-10 days embryonated duck eggs (EDE) through chorioallantoic membrane (CAM) route for the isolation of virus. The EDE died earlier was also chilled, and in a similar way, the CAMs were collected and again performed PCR for id entification of virus. Out of 41 PCR positive samples, 26 samples were isolated and reconfirmed by PCR. Subsequently, DPV was isolated in primary duck embryo fibroblasts cell culture and confirmed by observing cytopathic effect (CPE). Bang. J. Livs. Res. Vol. 26 (1&2), 2019: P. 73-78


Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
David Pellow ◽  
Alvah Zorea ◽  
Maraike Probst ◽  
Ori Furman ◽  
Arik Segal ◽  
...  

Abstract Background Metagenomic sequencing has led to the identification and assembly of many new bacterial genome sequences. These bacteria often contain plasmids: usually small, circular double-stranded DNA molecules that may transfer across bacterial species and confer antibiotic resistance. These plasmids are generally less studied and understood than their bacterial hosts. Part of the reason for this is insufficient computational tools enabling the analysis of plasmids in metagenomic samples. Results We developed SCAPP (Sequence Contents-Aware Plasmid Peeler)—an algorithm and tool to assemble plasmid sequences from metagenomic sequencing. SCAPP builds on some key ideas from the Recycler algorithm while improving plasmid assemblies by integrating biological knowledge about plasmids. We compared the performance of SCAPP to Recycler and metaplasmidSPAdes on simulated metagenomes, real human gut microbiome samples, and a human gut plasmidome dataset that we generated. We also created plasmidome and metagenome data from the same cow rumen sample and used the parallel sequencing data to create a novel assessment procedure. Overall, SCAPP outperformed Recycler and metaplasmidSPAdes across this wide range of datasets. Conclusions SCAPP is an easy to use Python package that enables the assembly of full plasmid sequences from metagenomic samples. It outperformed existing metagenomic plasmid assemblers in most cases and assembled novel and clinically relevant plasmids in samples we generated such as a human gut plasmidome. SCAPP is open-source software available from: https://github.com/Shamir-Lab/SCAPP.


mSystems ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Matthew R. Olm ◽  
Alexander Crits-Christoph ◽  
Spencer Diamond ◽  
Adi Lavy ◽  
Paula B. Matheus Carnevali ◽  
...  

ABSTRACT Longstanding questions relate to the existence of naturally distinct bacterial species and genetic approaches to distinguish them. Bacterial genomes in public databases form distinct groups, but these databases are subject to isolation and deposition biases. To avoid these biases, we compared 5,203 bacterial genomes from 1,457 environmental metagenomic samples to test for distinct clouds of diversity and evaluated metrics that could be used to define the species boundary. Bacterial genomes from the human gut, soil, and the ocean all exhibited gaps in whole-genome average nucleotide identities (ANI) near the previously suggested species threshold of 95% ANI. While genome-wide ratios of nonsynonymous and synonymous nucleotide differences (dN/dS) decrease until ANI values approach ∼98%, two methods for estimating homologous recombination approached zero at ∼95% ANI, supporting breakdown of recombination due to sequence divergence as a species-forming force. We evaluated 107 genome-based metrics for their ability to distinguish species when full genomes are not recovered. Full-length 16S rRNA genes were least useful, in part because they were underrecovered from metagenomes. However, many ribosomal proteins displayed both high metagenomic recoverability and species discrimination power. Taken together, our results verify the existence of sequence-discrete microbial species in metagenome-derived genomes and highlight the usefulness of ribosomal genes for gene-level species discrimination. IMPORTANCE There is controversy about whether bacterial diversity is clustered into distinct species groups or exists as a continuum. To address this issue, we analyzed bacterial genome databases and reports from several previous large-scale environment studies and identified clear discrete groups of species-level bacterial diversity in all cases. Genetic analysis further revealed that quasi-sexual reproduction via horizontal gene transfer is likely a key evolutionary force that maintains bacterial species integrity. We next benchmarked over 100 metrics to distinguish these bacterial species from each other and identified several genes encoding ribosomal proteins with high species discrimination power. Overall, the results from this study provide best practices for bacterial species delineation based on genome content and insight into the nature of bacterial species population genetics.


2016 ◽  
Vol 2 (5) ◽  
pp. e1600300 ◽  
Author(s):  
Ki Soo Park ◽  
Chen-Han Huang ◽  
Kyungheon Lee ◽  
Yeong-Eun Yoo ◽  
Cesar M. Castro ◽  
...  

Health care–associated infections (HAIs) and drug-resistant pathogens have become a major health care issue with millions of reported cases every year. Advanced diagnostics would allow clinicians to more quickly determine the most effective treatment, reduce the nonspecific use of broad-spectrum antimicrobials, and facilitate enrollment in new antibiotic treatments. We present a new integrated system, polarization anisotropy diagnostics (PAD), for rapid detection of HAI pathogens. The PAD uses changes of fluorescence anisotropy when detection probes recognize target bacterial nucleic acids. The technology is inherently robust against environmental noise and economically scalable for parallel measurements. The assay is fast (2 hours) and performed on-site in a single-tube format. When applied to clinical samples obtained from interventional procedures, the PAD determined the overall bacterial burden, differentiated HAI bacterial species, and identified drug resistance and virulence status. The PAD system holds promise as a powerful tool for near-patient, rapid HAI testing.


1980 ◽  
Vol 14 (1) ◽  
pp. 65-71 ◽  
Author(s):  
D. G. Byrne

The prevalence of depressive symptoms was estimated in a random sample of an Australian general population by administration of the Zung Self-Rating Depression Scale (S.D.S.). Rates, calculated according to criteria derived from a previously studied clinical sample, were somewhat higher in this population than had been reported in similar studies elsewhere. It was reasoned that this finding related to the relative laxity of criteria employed in the present study. Socio-demographic influences on the reporting of depressive symptoms were evident, the most prominent of these being the sex of the subject. It was suggested that these influences may underlie socio-demographic differences in rates of recognized depressive states occurring within clinical samples.


2021 ◽  
Vol 7 (6) ◽  
pp. 433
Author(s):  
Ahmad Ibrahim ◽  
Lucie Peyclit ◽  
Rim Abdallah ◽  
Saber Khelaifia ◽  
Amanda Chamieh ◽  
...  

Candida auris is an emerging multidrug-resistant yeast causing nosocomial infections and associated with high mortality in immunocompromised patients. Rapid identification and characterisation are necessary for diagnosis and containing its spread. In this study, we present a selective culture medium for all C. auris clades. This medium is sensitive with a limit of detection ranging between 101 and 102 CFU/mL. The 100% specificity of SCA (specific C. auris) medium is confirmed on a set of 135 Candida strains, 50 bacterial species and 200 human stool samples. Thus, this medium specifically selects for C. auris isolation from clinical samples, allowing the latter to study its phenotypic profile.


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