scholarly journals Genotyping of Francisella tularensis subsp. holarctica from Hares in Germany

2020 ◽  
Vol 8 (12) ◽  
pp. 1932
Author(s):  
Jörg Linde ◽  
Timo Homeier-Bachmann ◽  
Alexandra Dangel ◽  
Julia M. Riehm ◽  
David Sundell ◽  
...  

Francisella tularensis is the causative agent of the zoonotic disease tularemia. In Germany, most human infections are caused by contact with infected hares. The aim of this study was to characterize Francisella tularensis subsp. holarctica strains isolated from hares in Germany and to develop bioinformatics tools to analyze their genetic relatedness. In total, 257 German isolates—obtained mainly from hares (n = 233), other vertebrate animals, and ticks, but also from humans (n = 3)—were analyzed within this study. Publically available sequence data from 49 isolates were used to put our isolates into an epidemiological context and to compare isolates from natural foci and humans. Whole-genome sequences were analyzed using core-genome Multi-Locus-Sequence-Typing, canonical Single Nucleotide Polymorphism (SNP) typing and whole-genome SNP typing. An overall conformity of genotype clustering between the typing methods was found, albeit with a lower resolution for canonical single SNP typing. The subclade distribution, both on local and national levels, among strains from humans and hares was similar, suggesting circulation of the same genotypes both in animals and humans. Whilst close to identical isolates of the same subclade were found distributed over large areas, small geographical foci often harbored members of different subclades. In conclusion, although genomic high-resolution typing was shown to be robust, reproducible and allowed the identification of highly closely related strains, genetic profiling alone is not always conclusive for epidemiological linkage of F. tularensis strains.

2010 ◽  
Vol 93 (6) ◽  
pp. 1930-1943 ◽  
Author(s):  
Anders Johansson ◽  
Jeannine M Petersen

Abstract Francisella tularensis is a facultative, intracellular, zoonotic pathogen and the causative agent of tularemia. Historically, F. tularensis has been subdivided into subspecies on the basis of phenotypic traits, including biochemical reactivity and virulence. More recently, a number of genotypic methods, ranging from relatively insensitive methods to full genome sequencing, have been used to investigate genetic diversity within F. tularensis. These analyses indicate that F. tularensis is a pathogen of low sequence diversity with pair-wise average nucleotide identities >99.2 across subspecies. Nonetheless, genomic rearrangements and sequence deletions exist between and within F. tularensis subspecies, creating polymorphisms detectable by genotyping methods. Genetic subpopulations intermediate to the subspecies and strain level have been identified within F. tularensis subsp. tularensis and F. tularensis subsp. holarctica by several different typing methods. These genetic subpopulations have been associated with differences in disease severity, geographic distribution, and transmission patterns. For example, one F. tularensis subsp. tularensis subpopulation has been found to be significantly associated with mortality in humans. Additionally, genotypic analyses of Francisella spp. have provided information for use in the rational design of strain panels for validation of F. tularensis diagnostic tests. This review provides a guide to the various F. tularensis genotyping methods.


Author(s):  
M. V. Tsimbalistova ◽  
V. M. Sorokin ◽  
N. V. Aronova ◽  
A. S. Anisimova ◽  
N. L. Pichurina ◽  
...  

Objective of the study was to investigate biological properties and genetic characteristics of tularemia agent strains isolated from natural foci of the Rostov Region in 2020.Materials and methods. Field material from natural foci of the Rostov Region was examined by serological, bacteriological, biological, and molecular-genetic methods. Cultural-morphological, biochemical, antigenic and pathogenic properties of isolated cultures were studied. Protein profles were obtained through MALDI-TOF MS using mass spectrometer Autoflex speed III Bruker Daltonics and Flex Control of Biotyper software. The genetic characteristics of the strains were determined by VNTR and INDEL typing and SNP analysis.Results and discussion. Six strains of tularemia pathogen were isolated from mouse-like rodents using biological method. The investigation of their biological features and data of PCR analysis and INDEL typing with canonical markers showed that all strains are typical representatives of the Francisella tularensis subsp. holarctica biovar EryR. VNTR typing by six genetic loci revealed that all strains belong to four individual genotypes. The strain isolated in 2020 in the Salsky district was identical to the strain which was isolated in the same area in 1989. Based on the whole genome sequencing of two strains, we established that they are closest to the cultures isolated in Turkey (2009, 2012) and Khanty-Mansiysk (2013) by the studied set of SNP markers. Thus, we found that both identical (or closely related) clones of the tularemia agent and new strains with unique genotypes which previously were not described for the Rostov Region can circulate in natural foci of this region for a long period of time.


Author(s):  
Amnon Koren ◽  
Dashiell J Massey ◽  
Alexa N Bracci

Abstract Motivation Genomic DNA replicates according to a reproducible spatiotemporal program, with some loci replicating early in S phase while others replicate late. Despite being a central cellular process, DNA replication timing studies have been limited in scale due to technical challenges. Results We present TIGER (Timing Inferred from Genome Replication), a computational approach for extracting DNA replication timing information from whole genome sequence data obtained from proliferating cell samples. The presence of replicating cells in a biological specimen leads to non-uniform representation of genomic DNA that depends on the timing of replication of different genomic loci. Replication dynamics can hence be observed in genome sequence data by analyzing DNA copy number along chromosomes while accounting for other sources of sequence coverage variation. TIGER is applicable to any species with a contiguous genome assembly and rivals the quality of experimental measurements of DNA replication timing. It provides a straightforward approach for measuring replication timing and can readily be applied at scale. Availability and Implementation TIGER is available at https://github.com/TheKorenLab/TIGER. Supplementary information Supplementary data are available at Bioinformatics online


Data in Brief ◽  
2020 ◽  
Vol 33 ◽  
pp. 106416
Author(s):  
Asset Daniyarov ◽  
Askhat Molkenov ◽  
Saule Rakhimova ◽  
Ainur Akhmetova ◽  
Zhannur Nurkina ◽  
...  

Diversity ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 109 ◽  
Author(s):  
Rebecca T. Kimball ◽  
Carl H. Oliveros ◽  
Ning Wang ◽  
Noor D. White ◽  
F. Keith Barker ◽  
...  

It has long been appreciated that analyses of genomic data (e.g., whole genome sequencing or sequence capture) have the potential to reveal the tree of life, but it remains challenging to move from sequence data to a clear understanding of evolutionary history, in part due to the computational challenges of phylogenetic estimation using genome-scale data. Supertree methods solve that challenge because they facilitate a divide-and-conquer approach for large-scale phylogeny inference by integrating smaller subtrees in a computationally efficient manner. Here, we combined information from sequence capture and whole-genome phylogenies using supertree methods. However, the available phylogenomic trees had limited overlap so we used taxon-rich (but not phylogenomic) megaphylogenies to weave them together. This allowed us to construct a phylogenomic supertree, with support values, that included 707 bird species (~7% of avian species diversity). We estimated branch lengths using mitochondrial sequence data and we used these branch lengths to estimate divergence times. Our time-calibrated supertree supports radiation of all three major avian clades (Palaeognathae, Galloanseres, and Neoaves) near the Cretaceous-Paleogene (K-Pg) boundary. The approach we used will permit the continued addition of taxa to this supertree as new phylogenomic data are published, and it could be applied to other taxa as well.


2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Lynsey K. Whitacre ◽  
Jesse L. Hoff ◽  
Robert D. Schnabel ◽  
Sara Albarella ◽  
Francesca Ciotola ◽  
...  

2016 ◽  
Vol 14 (1) ◽  
Author(s):  
Crystal N. Propst ◽  
Albert O. Nwabueze ◽  
Igor L. Kanev ◽  
Rachel E. Pepin ◽  
Bradford W. Gutting ◽  
...  

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