scholarly journals Whole-genome sequencing of SARS-CoV-2 in the Republic of Ireland during waves 1 and 2 of the pandemic

Author(s):  
P.W.G. Mallon ◽  
F. Crispie ◽  
G. Gonzalez ◽  
W. Tinago ◽  
A.A. Garcia Leon ◽  
...  

AbstractBackgroundWhole-genome sequencing (WGS) of SARS-CoV-2 laboratory-confirmed cases can provide insights into viral transmission and genetic diversity at a population level. However, less is known about the impact of non-pharmaceutical interventions (NPIs), including ‘lockdowns’, on circulating SARS-CoV-2 lineages and variants of concern, the relative contribution of travel to re-emergence of pandemic waves within communities or how different lineages and variants contribute to disease severity.MethodsWe have conducted an analysis within a prospective, multicentre observational study of individuals attending four hospitals in the South-East of Ireland with COVID-19. Samples underwent WGS from which lineages and variants were assigned, lineage frequency was plotted over time and phylogenetic analysis was employed to determine the origin of variants detected post-lockdown. Univariate and multivariate analyses assessed relationships between viral lineage/variant and COVID-19 disease severity.ResultsWe analysed 225 genome sequences across two SARS-CoV-2 waves, 134 (59.6%) from wave 1 (March to June) and 91 (40.4%) from wave 2 (July to December), representing 15.2% of COVID-19 admissions to these hospitals during the sampling periods. Four variants (B.1.1.162, B1.1.70, B.1.1.267 and B.1.1) comprised 68% of variants detected during wave 1. Of these variants, only a single B.1.1.70 sequence was detected in wave 2, while the B.1.177 lineage emerged and contributed to 82.3% of lineages detected. Phylogenetic analysis suggested multiple introductions of wave 2 variants from outside Ireland. We found no consistent association between SARS-CoV-2 lineages and disease severity.ConclusionsThese data suggest elimination of common SARS-CoV-2 lineages from hospitalised cases associated with effective NPIs and that importation of new viral variants through travel was a significant contributor to the re-emergence of the pandemic in the second wave in Ireland. Our findings highlight the importance of genomic surveillance in identifying circulating viral genetic diversity and variants of concern and, also, modelling the disease burden of SARS-CoV-2.

2021 ◽  
Author(s):  
Andrey A. Kritsky ◽  
Yaroslav M. Krasnov ◽  
Mamadou Keita ◽  
Sakoba Keita ◽  
Andrey V. Fedorov ◽  
...  

Genetic diversity of SARS-CoV-2 isolates circulating in the Republic of Guinea in May and June 2020, as well as in March 2021, has been demonstrated using fragment (S gene) and whole genome sequencing of 14 strains. Analysis of nucleotide sequences and phylogenetic constructs make it possible to divide the studied strains into 3 groups. Comparison of the obtained data with the already available epidemiological data proves the initial importation of COVID-19 from Western European countries, and also demonstrates four independent import routes in two time periods (March 2020 and no later than March 2021).


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Peter Higgins ◽  
Cooper A Grace ◽  
Soon A Lee ◽  
Matthew R Goddard

Abstract Saccharomyces cerevisiae is extensively utilized for commercial fermentation, and is also an important biological model; however, its ecology has only recently begun to be understood. Through the use of whole-genome sequencing, the species has been characterized into a number of distinct subpopulations, defined by geographical ranges and industrial uses. Here, the whole-genome sequences of 104 New Zealand (NZ) S. cerevisiae strains, including 52 novel genomes, are analyzed alongside 450 published sequences derived from various global locations. The impact of S. cerevisiae novel range expansion into NZ was investigated and these analyses reveal the positioning of NZ strains as a subgroup to the predominantly European/wine clade. A number of genomic differences with the European group correlate with range expansion into NZ, including 18 highly enriched single-nucleotide polymorphism (SNPs) and novel Ty1/2 insertions. While it is not possible to categorically determine if any genetic differences are due to stochastic process or the operations of natural selection, we suggest that the observation of NZ-specific copy number increases of four sugar transporter genes in the HXT family may reasonably represent an adaptation in the NZ S. cerevisiae subpopulation, and this correlates with the observations of copy number changes during adaptation in small-scale experimental evolution studies.


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.


2020 ◽  
Vol 35 (4) ◽  
pp. 237-242
Author(s):  
Ya. M. Krasnov ◽  
Zh. V. Alkhova ◽  
S. V. Generalov ◽  
I. V. Tuchkov ◽  
E. A. Naryshkina ◽  
...  

2018 ◽  
Vol 57 (7) ◽  
pp. 905-908 ◽  
Author(s):  
David New ◽  
Alicia G Beukers ◽  
Sarah E Kidd ◽  
Adam J Merritt ◽  
Kerry Weeks ◽  
...  

AbstractWhole genome sequencing (WGS) was used to demonstrate the wide genetic variability within Sporothrix schenckii sensu lato and establish that there are two main species of Sporothrix within Australian clinical isolates—S. schenckii sensu stricto and Sporothrix globosa. We also demonstrated southwest Western Australia contained genetically similar S. schenckii ss strains that are distinct from strains isolated in the eastern and northern states of Australia. Some genetic clustering by region was also noted for northern NSW, Queensland, and Northern Territory. Phylogenetic analysis of WGS data provided greater phylogenetic resolution compared to analysis of the calmodulin gene alone.


2017 ◽  
Vol 62 (1) ◽  
Author(s):  
Tse H. Koh ◽  
Nurdyana Binte Abdul Rahman ◽  
Jeanette W. P. Teo ◽  
My-Van La ◽  
Balamurugan Periaswamy ◽  
...  

ABSTRACT Whole-genome sequencing was performed on 16 isolates of the carbapenemase-producing Enterobacter cloacae complex to determine the flanking regions of bla IMI-type genes. Phylogenetic analysis of multilocus sequence typing (MLST) targets separated the isolates into 4 clusters. The bla IMI-type genes were all found on Xer-dependent integrative mobile elements (IMEX). The IMEX elements of 5 isolates were similar to those described in Canada, while the remainder were novel. Five isolates had IMEX elements lacking a resolvase and recombinase.


Antibiotics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1152
Author(s):  
Samuel M. Chekabab ◽  
John R. Lawrence ◽  
Alvin C. Alvarado ◽  
Bernardo Z. Predicala ◽  
Darren R. Korber

In response to new stringent regulations in Canada regarding the use of antibiotics in animal production, many farms have implemented practices to produce animals that are raised without antibiotics (RWA) from birth to slaughter. This study aims to assess the impact of RWA production practices on reducing the actual total on-farm use of antibiotics, the occurrence of pathogens, and the prevalence of antimicrobial resistance (AMR). A 28-month longitudinal surveillance of farms that adopted the RWA program and conventional farms using antibiotics in accordance with the new regulations (non-RWA) was conducted by collecting fecal samples from 6-week-old pigs and composite manure from the barn over six time points and applying whole-genome sequencing (WGS) to assess the prevalence of AMR genes as well as the abundance of pathogens. Analysis of in-barn drug use records confirmed the decreased consumption of antibiotics in RWA barns compared to non-RWA barns. WGS analyses revealed that RWA barns had reduced the frequency of AMR genes in piglet feces and in-barn manure. However, metagenomic analyses showed that RWA barns had a significant increase in the frequency of pathogenic Firmicutes in fecal samples and pathogenic Proteobacteria in barn manure samples.


2018 ◽  
Author(s):  
David R. Greig ◽  
Ulf Schafer ◽  
Sophie Octavia ◽  
Ebony Hunter ◽  
Marie A. Chattaway ◽  
...  

AbstractEpidemiological and microbiological data on Vibrio cholerae isolated between 2004 and 2017 (n=836) and held in the Public Health England culture archive were reviewed. The traditional biochemical species identification and serological typing results were compared with the genome derived species identification and serotype for a sub-set of isolates (n=152). Of the 836 isolates, 750 (89.7%) were from faecal specimens, 206 (24.6%) belonged to serogroup O1 and seven (0.8%) were serogroup O139, and 792 (94.7%) isolates from patients reporting recent travel abroad, most commonly to India (n=209) and Pakistan (n=104). Of the 152 isolates of V. cholerae speciated by kmer identification, 149 (98.1%) were concordant with the traditional biochemical approach. Traditional serotyping results were 100% concordant with the whole genome sequencing (WGS) analysis for identification of serogroups O1 and O139 and Classical and El Tor biotypes. ctxA was detected in all isolates of V. cholerae O1 El Tor and O139 belonging to sequence type (ST) 69, and in V. cholerae O1 Classical variants belonging to ST73. A phylogeny of isolates belonging to ST69 from UK travellers clustered geographically, with isolates from India and Pakistan located on separate branches. Moving forward, WGS data from UK travellers will contribute to global surveillance programs, and the monitoring of emerging threats to public health and the global dissemination of pathogenic lineages. At the national level, these WGS data will inform the timely reinforcement of direct public health messaging to travellers and mitigate the impact of imported infections and the associated risks to public health.


2020 ◽  
Author(s):  
Inès Levade ◽  
Ashraful I. Khan ◽  
Fahima Chowdhury ◽  
Stephen B. Calderwood ◽  
Edward T. Ryan ◽  
...  

ABSTRACTVibrio cholerae can cause a range of symptoms in infected patients, ranging from severe diarrhea to asymptomatic infection. Previous studies using whole genome sequencing (WGS) of multiple bacterial isolates per patient have shown that Vibrio cholerae can evolve a modest amount of genetic diversity during symptomatic infection. Little is known about V. cholerae genetic diversity within asymptomatic infected patients. To achieve increased resolution in the detection of Vibrio cholerae diversity within individual infections, we applied culture-based population genomics and metagenomics to a cohort of symptomatic and asymptomatic cholera patients. While the metagenomic approach allowed us to detect more mutations in symptomatic patients compared to the culture-based approach, WGS of isolates was still necessary to detect V. cholerae diversity in asymptomatic carriers, likely due to their low Vibrio cholerae load. We found that symptomatic and asymptomatic patients contain similar levels of within-patient diversity, and discovered V. cholerae hypermutators in some patients. While hypermutators appeared to generate mostly selectively neutral mutations, non-mutators showed signs of convergent mutation across multiple patients, suggesting V. cholerae adaptation within hosts. Our results highlight the power of metagenomics combined with isolate sequencing to characterize within-patient diversity in acute V. cholerae infection and asymptomatic infection, while providing evidence for hypermutator phenotypes within cholera patients.IMPORTANCEPathogen evolution within patients can impact phenotypes such as drug resistance and virulence, potentially affecting clinical outcomes. V. cholerae infection can result in life-threatening diarrheal disease, or asymptomatic infection. Here we describe whole-genome sequencing of V. cholerae isolates and culture-free metagenomic sequencing from stool of symptomatic cholera patients and asymptomatic carriers. Despite the acuteness of cholera infections, we found evidence for adaptive mutations in the V. cholerae genome that occur independently and repeatedly within multiple symptomatic patients. We also identified V. cholerae hypermutator phenotypes within 6 out of 14 patients, which appear to generate mainly neutral or deleterious mutations. Our work sets the stage for future studies of the role of hypermutators and within-patient evolution in explaining the variation from asymptomatic carriage to symptomatic cholera.


2018 ◽  
Vol 56 (11) ◽  
Author(s):  
David R. Greig ◽  
Ulf Schaefer ◽  
Sophie Octavia ◽  
Ebony Hunter ◽  
Marie A. Chattaway ◽  
...  

ABSTRACT Epidemiological and microbiological data on Vibrio cholerae strains isolated between April 2004 and March 2018 (n = 836) and held at the Public Health England culture archive were reviewed. The traditional biochemical species identification and serological typing results were compared with the genome-derived species identification and serotype for a subset of isolates (n = 152). Of the 836 isolates, 750 (89.7%) were from a fecal specimen, 206 (24.6%) belonged to serogroup O1, and 7 (0.8%) were serogroup O139; 792 (94.7%) isolates were from patients reporting recent travel abroad, most commonly to India (n = 209) and Pakistan (n = 104). Of the 152 V. cholerae isolates identified by use of kmer, 149 (98.1%) were concordant with those identified using the traditional biochemical approach. Traditional serotyping results were 100% concordant with those of the whole-genome sequencing (WGS) analysis for the identification of serogroups O1 and O139 and classical and El Tor biotypes. ctxA was detected in all isolates of V. cholerae O1 El Tor and O139 belonging to sequence type 69 (ST69) and in V. cholerae O1 classical variants belonging to ST73. A phylogeny of isolates belonging to ST69 from U.K. travelers clustered geographically, with isolates from India and Pakistan located on separate branches. Moving forward, WGS data from U.K. travelers will contribute to global surveillance programs and the monitoring of emerging threats to public health and the global dissemination of pathogenic lineages. At the national level, these WGS data will inform the timely reinforcement of direct public health messaging to travelers and mitigate the impact of imported infections and the associated risks to public health.


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