Phylogenetic Analysis of Yersinia pestis Strains of the Caucasian Subspecies from the Foci of the Caucasus and Transcaucasia according to the Whole Genome Sequencing Data

2019 ◽  
Vol 55 (4) ◽  
pp. 426-432
Author(s):  
K. A. Nikiforov ◽  
Zh. V. Al’khova ◽  
L. M. Kukleva ◽  
E. A. Naryshkina ◽  
E. G. Oglodin ◽  
...  
2019 ◽  
Vol 57 (6) ◽  
Author(s):  
R. C. Jones ◽  
L. G. Harris ◽  
S. Morgan ◽  
M. C. Ruddy ◽  
M. Perry ◽  
...  

ABSTRACT An inability to standardize the bioinformatic data produced by whole-genome sequencing (WGS) has been a barrier to its widespread use in tuberculosis phylogenetics. The aim of this study was to carry out a phylogenetic analysis of tuberculosis in Wales, United Kingdom, using Ridom SeqSphere software for core genome multilocus sequence typing (cgMLST) analysis of whole-genome sequencing data. The phylogenetics of tuberculosis in Wales have not previously been studied. Sixty-six Mycobacterium tuberculosis isolates (including 42 outbreak-associated isolates) from south Wales were sequenced using an Illumina platform. Isolates were assigned to principal genetic groups, single nucleotide polymorphism (SNP) cluster groups, lineages, and sublineages using SNP-calling protocols. WGS data were submitted to the Ridom SeqSphere software for cgMLST analysis and analyzed alongside 179 previously lineage-defined isolates. The data set was dominated by the Euro-American lineage, with the sublineage composition being dominated by T, X, and Haarlem family strains. The cgMLST analysis successfully assigned 58 isolates to major lineages, and the results were consistent with those obtained by traditional SNP mapping methods. In addition, the cgMLST scheme was used to resolve an outbreak of tuberculosis occurring in the region. This study supports the use of a cgMLST method for standardized phylogenetic assignment of tuberculosis isolates and for outbreak resolution and provides the first insight into Welsh tuberculosis phylogenetics, identifying the presence of the Haarlem sublineage commonly associated with virulent traits.


2021 ◽  
Vol 97 (6) ◽  
pp. 587-593
Author(s):  
A. S. Vodopianov ◽  
R. V. Pisanov ◽  
S. O. Vodopianov ◽  
I. P. Oleynikov

Aim. To improve the method of the quality assessment of single nucleotide polymorphisms, which are used for SNP-typing, based on the analysis of their distribution in the primary data of whole genome sequencing (reads).Materials and methods. Data of the whole genome sequencing of 56 Vibrio cholerae strains obtained using different types of sequencers were used. The software was developed using Java programming language. Cluster analysis and construction of the dendrogram were performed with the author's software using the UPGMA method.Results and discussion. The «instability» of detection the number of SNP in the genome of cholera causative agent was shown. The method of selection of the SNP list for phylogenetic analysis based on the analysis of the primary data of whole genome sequencing (reads), has been developed. The method of using «control genomes» for cluster analysis of whole genome sequencing data has been proposed.Conclusion. The list of 3198 «stable SNP» for phylogenetic analysis has been composed. Genetic affinity between the non-toxigenic strains that contain the tcpA gene (ctxAB–tcpA+) and preCTX-strains of V. cholerae was shown.


Heredity ◽  
2021 ◽  
Author(s):  
Axel Jensen ◽  
Mette Lillie ◽  
Kristofer Bergström ◽  
Per Larsson ◽  
Jacob Höglund

AbstractThe use of genetic markers in the context of conservation is largely being outcompeted by whole-genome data. Comparative studies between the two are sparse, and the knowledge about potential effects of this methodology shift is limited. Here, we used whole-genome sequencing data to assess the genetic status of peripheral populations of the wels catfish (Silurus glanis), and discuss the results in light of a recent microsatellite study of the same populations. The Swedish populations of the wels catfish have suffered from severe declines during the last centuries and persists in only a few isolated water systems. Fragmented populations generally are at greater risk of extinction, for example due to loss of genetic diversity, and may thus require conservation actions. We sequenced individuals from the three remaining native populations (Båven, Emån, and Möckeln) and one reintroduced population of admixed origin (Helge å), and found that genetic diversity was highest in Emån but low overall, with strong differentiation among the populations. No signature of recent inbreeding was found, but a considerable number of short runs of homozygosity were present in all populations, likely linked to historically small population sizes and bottleneck events. Genetic substructure within any of the native populations was at best weak. Individuals from the admixed population Helge å shared most genetic ancestry with the Båven population (72%). Our results are largely in agreement with the microsatellite study, and stresses the need to protect these isolated populations at the northern edge of the distribution of the species.


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