scholarly journals A FOUNDER EFFECT LED EARLY SARS-COV-2 TRANSMISSION IN SPAIN

Author(s):  
Francisco Díez-Fuertes ◽  
María Iglesias-Caballero ◽  
Javier García Pérez ◽  
Sara Monzón ◽  
Pilar Jiménez ◽  
...  

SARS-CoV-2 whole-genome analysis has identified five large clades worldwide, emerged in 2019 (19A and 19B) and in 2020 (20A, 20B and 20C). This study aims to analyze the diffusion of SARS-CoV-2 in Spain using maximum likelihood phylogenetic and Bayesian phylodynamic analyses. The most recent common ancestor (MRCA) of the SARS-CoV-2 pandemic was estimated in Wuhan, China, around November 24, 2019. Phylogenetic analyses of the first 12,511 SARS-CoV-2 whole genome sequences obtained worldwide, including 290 from 11 different regions of Spain, revealed 62 independent introductions of the virus in the country. Most sequences from Spain were distributed in clades characterized by D614G substitution in S gene (20A, 20B and 20C) and L84S substitution in ORF8 (19B) with 163 and 118 sequences, respectively, with the remaining sequences branching in 19A. A total of 110 (38%) sequences from Spain grouped in four different monophyletic clusters of 20A clade (20A-Sp1 and 20A-Sp2) and 19B clade (19B-Sp1 and 19B-Sp2) along with sequences from 29 countries worldwide. The MRCA of 19A-Sp1, 20A-Sp1, 19A-Sp2 and 20A-Sp2 clusters were estimated in Spain around January 21 and 29, and February 6 and 17, 2020, respectively. The prevalence of 19B clade in Spain (40%) was by far higher than in any other European country during the first weeks of the epidemic, probably by a founder effect. However, this variant was replaced by G614-bearing viruses in April. In vitro assays showed an enhanced infectivity of pseudotyped virions displaying G614 substitution compared with D614, suggesting a fitness advantage of D614G. IMPORTANCE Multiple SARS-CoV-2 introductions have been detected in Spain and at least four resulted in the emergence of locally transmitted clusters originated not later than mid-February, with further dissemination to many other countries around the world and a few weeks before the explosion of COVID-19 cases detected in Spain during the first week of March. The majority of the earliest variants detected in Spain branched in 19B clade (D614 viruses), which was the most prevalent clade during the first weeks of March, pointing to a founder effect. However, from mid-March to June, 2020, G614-bearing viruses (20A, 20B and 20C clades) overcame D614 variants in Spain, probably as a consequence of an evolutionary advantage of this substitution in the spike protein. A higher infectivity of G614-bearing viruses compared to D614 variants was detected, suggesting that this substitution in SARS-CoV-2 spike protein could be behind the variant shift observed in Spain.

Author(s):  
Francisco Díez-Fuertes ◽  
María Iglesias-Caballero ◽  
Sara Monzón ◽  
Pilar Jiménez ◽  
Sarai Varona ◽  
...  

AbstractObjectivesSARS-CoV-2 whole-genome analysis has identified three large clades spreading worldwide, designated G, V and S. This study aims to analyze the diffusion of SARS-CoV-2 in Spain/Europe.MethodsMaximum likelihood phylogenetic and Bayesian phylodynamic analyses have been performed to estimate the most probable temporal and geographic origin of different phylogenetic clusters and the diffusion pathways of SARS-CoV-2.ResultsPhylogenetic analyses of the first 28 SARS-CoV-2 whole genome sequences obtained from patients in Spain revealed that most of them are distributed in G and S clades (13 sequences in each) with the remaining two sequences branching in the V clade. Eleven of the Spanish viruses of the S clade and six of the G clade grouped in two different monophyletic clusters (S-Spain and G-Spain, respectively), with the S-Spain cluster also comprising 8 sequences from 6 other countries from Europe and the Americas. The most recent common ancestor (MRCA) of the SARS-CoV-2 pandemic was estimated in the city of Wuhan, China, around November 24, 2019, with a 95% highest posterior density (HPD) interval from October 30-December 17, 2019. The origin of S-Spain and G-Spain clusters were estimated in Spain around February 14 and 18, 2020, respectively, with a possible ancestry of S-Spain in Shanghai.ConclusionsMultiple SARS-CoV-2 introductions have been detected in Spain and at least two resulted in the emergence of locally transmitted clusters, with further dissemination of one of them to at least 6 other countries. These results highlight the extraordinary potential of SARS-CoV-2 for rapid and widespread geographic dissemination.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shingo Nishiki ◽  
Kenichi Lee ◽  
Mizue Kanai ◽  
Shu-ichi Nakayama ◽  
Makoto Ohnishi

AbstractJapan has had a substantial increase in syphilis cases since 2013. However, research on the genomic features of the Treponema pallidum subspecies pallidum (TPA) strains from these cases has been limited. Here, we elucidated the genetic variations and relationships between TPA strains in Japan (detected between 2014 and 2018) and other countries by whole-genome sequencing and phylogenetic analyses, including syphilis epidemiological surveillance data and information on patient sexual orientation. Seventeen of the 20 strains in Japan were SS14- and the remaining 3 were Nichols-lineage. Sixteen of the 17 SS14-lineage strains were classified into previously reported Sub-lineage 1B. Sub-lineage 1B strains in Japan have formed distinct sub-clusters of strains from heterosexuals and strains from men who have sex with men. These strains were closely related to reported TPA strains in China, forming an East-Asian cluster. However, those strains in these countries evolved independently after diverging from their most recent common ancestor and expanded their genetic diversity during the time of syphilis outbreak in each country. The genetic difference between the TPA strains in these countries was characterized by single-nucleotide-polymorphism analyses of their penicillin binding protein genes. Taken together, our results elucidated the detailed phylogenetic features and transmission networks of syphilis.


Author(s):  
Satoshi Nakano ◽  
Takao Fujisawa ◽  
Bin Chang ◽  
Yutaka Ito ◽  
Hideki Akeda ◽  
...  

After the introduction of the seven-valent pneumococcal conjugate vaccine, the global spread of multidrug resistant serotype 19A-ST320 strains became a public health concern. In Japan, the main genotype of serotype 19A was ST3111, and the identification rate of ST320 was low. Although the isolates were sporadically detected in both adults and children, their origin remains unknown. Thus, by combining pneumococcal isolates collected in three nationwide pneumococcal surveillance studies conducted in Japan between 2008 and 2020, we analyzed 56 serotype 19A-ST320 isolates along with 931 global isolates, using whole-genome sequencing to uncover the transmission route of the globally distributed clone in Japan. The clone was frequently detected in Okinawa Prefecture, where the U.S. returned to Japan in 1972. Phylogenetic analysis demonstrated that the isolates from Japan were genetically related to those from the U.S.; therefore, the common ancestor may have originated in the U.S. In addition, Bayesian analysis suggested that the time to the most recent common ancestor of the isolates form Japan and the U.S. was approximately the 1990s to 2000, suggesting the possibility that the common ancestor could have already spread in the U.S. before the Taiwan 19F-14 isolate was first identified in a Taiwanese hospital in 1997. The phylogeographical analysis supported the transmission of the clone from the U.S. to Japan, but the analysis could be influenced by sampling bias. These results suggested the possibility that the serotype 19A-ST320 clone had already spread in the U.S. before being imported into Japan.


2020 ◽  
Author(s):  
Babatunde Olarenwaju Motayo ◽  
Olukunle Oluwapamilerin Oluwasemowo ◽  
Paul Akiniyi Akinduti ◽  
Babatunde Adebiyi Olusola ◽  
Olumide T Aerege ◽  
...  

ABSTRACTThe ongoing SARSCoV-2 pandemic was introduced into Africa on 14th February 2020 and has rapidly spread across the continent causing severe public health crisis and mortality. We investigated the genetic diversity and evolution of this virus during the early outbreak months using whole genome sequences. We performed; recombination analysis against closely related CoV, Bayesian time scaled phylogeny and investigated spike protein amino acid mutations. Results from our analysis showed recombination signals between the AfrSARSCoV-2 sequences and reference sequences within the N and S genes. The evolutionary rate of the AfrSARSCoV-2 was 4.133 × 10−4 high posterior density HPD (4.132 × 10−4 to 4.134 × 10−4) substitutions/site/year. The time to most recent common ancestor TMRCA of the African strains was December 7th 2019. The AfrSARCoV-2 sequences diversified into two lineages A and B with B being more diverse with multiple sub-lineages confirmed by both maximum clade credibility MCC tree and PANGOLIN software. There was a high prevalence of the D614-G spike protein amino acid mutation (82.61%) among the African strains. Our study has revealed a rapidly diversifying viral population with the G614 spike protein variant dominating, we advocate for up scaling NGS sequencing platforms across Africa to enhance surveillance and aid control effort of SARSCoV-2 in Africa.


Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1017
Author(s):  
Hirohisa Mekata ◽  
Tomohiro Okagawa ◽  
Satoru Konnai ◽  
Takayuki Miyazawa

Bovine foamy virus (BFV) is a member of the foamy virus family in cattle. Information on the epidemiology, transmission routes, and whole-genome sequences of BFV is still limited. To understand the characteristics of BFV, this study included a molecular survey in Japan and the determination of the whole-genome sequences of 30 BFV isolates. A total of 30 (3.4%, 30/884) cattle were infected with BFV according to PCR analysis. Cattle less than 48 months old were scarcely infected with this virus, and older animals had a significantly higher rate of infection. To reveal the possibility of vertical transmission, we additionally surveyed 77 pairs of dams and 3-month-old calves in a farm already confirmed to have BFV. We confirmed that one of the calves born from a dam with BFV was infected. Phylogenetic analyses revealed that a novel genotype was spread in Japan. In conclusion, the prevalence of BFV in Japan is relatively low and three genotypes, including a novel genotype, are spread in Japan.


1998 ◽  
Vol 88 (8) ◽  
pp. 782-787 ◽  
Author(s):  
Drake C. Stenger ◽  
Jeffrey S. Hall ◽  
Il-Ryong Choi ◽  
Roy French

The complete nucleotide sequence of wheat streak mosaic virus (WSMV) has been determined based on complementary DNA clones derived from the 9,384-nucleotide (nt) RNA of the virus. The genome of WSMV has a 130-nt 5′ leader and 149-nt 3′-untranslated region and is polyadenylated at the 3′ end. WSMV RNA encodes a single polyprotein of 3,035 amino acid residues and has a deduced genome organization typical for a member of the family Potyviridae (5′-P1/HC-Pro/P3/6K1/CI/6K2/VPg-NIa/NIb/CP-3′). Because WSMV shares with ryegrass mosaic virus (RGMV) the biological property of transmission by eriophyid mites, WSMV has been assigned to the genus Rymovirus, of which RGMV is the type species. Phylogenetic analyses were conducted with complete polyprotein or NIb protein sequences of 11 members of the family Potyviridae, including viruses of monocots or dicots and viruses transmitted by aphids, whiteflies, and mites. WSMV and the monocot-infecting, mite-transmitted brome streak mosaic virus (BrSMV) are sister taxa and share a most recent common ancestor with the whitefly-transmitted sweet potato mild mottle virus, the type species of the proposed genus “Ipomovirus.” In contrast, RGMV shares a most recent common ancestor with aphid-transmitted species of the genus Potyvirus. These results indicate that WSMV and BrSMV should be classified within a new genus of the family Potyviridae and should not be considered species of the genus Rymovirus.


2015 ◽  
Vol 33 (3_suppl) ◽  
pp. 308-308
Author(s):  
Bo Hyun Kim ◽  
Yeon-Su Lee ◽  
Byung Chul Kim ◽  
Aesun Shin ◽  
Jin Sook Kim ◽  
...  

308 Background: Reliable biomarkers are required to predict patient response to sorafenib. We attempted to investigate genomic variations associated with responsiveness to sorafenib treatment in patients with unresectable hepatocellular carcinoma (HCC) and their functional relevance. Methods: We obtained blood samples from 4 strong and 3 poor responders to sorafenib treatment and subjected these samples to whole-genome analysis. Next, we performed validation tests for candidate single-nucleotide polymorphisms (SNPs) in the samples of 174 HCC patients who were treated with sorafenib, followed by in vitro functional analysis and in silico analyses of candidate SNPs. Results: On average, 90 gigabases/sample was generated at ~34X sequencing depth. In total, 1813 genomic variations were perfectly matched to sorafenib responses in the clinical data; 708 were located within regions for sorafenib-target genes or drug absorption, distribution, metabolism, and excretion (ADME)-related genes—36 within the coding regions and 6 identified as non-synonymous single-nucleotide variants from 4 ADME-related genes (ABCB1, FMO3, MUSK, and SLC15A2), which potentially cause functional alterations. Validation tests of 174 patients confirmed sequencing results and revealed that patients with the C/C genotype for rs2257212 in SCL15A2 displayed higher risk for cancer progression than did patients with C/T or T/T genotypes (HR: 2.18; 95% CI, 1.15–4.15; P = 0.018). In vitro functional analysis revealed that cells harboring C/C genotype for this SNP displayed lower response to sorafenib treatment than did cells harboring the T/T genotype. Structural prediction analysis revealed change in protein phosphorylation levels, potentially affecting sorafenib-associated enzymatic activity. Conclusions: SLC15A2 could be a robust biomarker of response to sorafenib treatment in HCC patients.


2021 ◽  
Author(s):  
Lingyun Chen ◽  
Bei Lu ◽  
Diego F. Morales-Briones ◽  
Michael L. Moody ◽  
Fan Liu ◽  
...  

Land plants first evolved from freshwater algae, and flowering plants returned to water as early as the Cretaceous and multiple times beyond. Alismatales is the largest clade of aquatic angiosperms including all marine angiosperms, as well as terrestrial plants. We used Alismatales to explore plant adaptation to aquatic environments by including 95 samples (89 Alismatales species) covering four genomes and 91 transcriptomes (59 generated in this study). To provide a basis for investigating adaptation, we assessed phylogenetic conflict and whole-genome duplication (WGD) events in Alismatales. We recovered a relationship for the three main clades in Alismatales as ((Tofieldiaceae, Araceae), core Alismatids). There is phylogenetic conflict among the backbone of the three main clades that could be due to incomplete lineage sorting and introgression. We identified 18 putative WGD events. One of them had occurred at the most recent common ancestor of core Alismatids, and four occurred at seagrass lineages. Other events are distributed in terrestrial, emergent, and submersed life-forms and seagrasses across Alismatales. We also found that lineage and life-form were each important for different evolutionary patterns for the genes related to freshwater/marine adaptation. For example, some light or ethylene-related genes were lost in the seagrass Zosteraceae, but present in other seagrasses and freshwater species. Stomata-related genes were lost in both submersed freshwater species and seagrasses. Nicotianamine synthase genes, which are important in iron intake, expanded in both submersed freshwater species and seagrasses. Our results advance the understanding of the adaptation to aquatic environments, phylogeny, and whole-genome duplication of Alismatales.


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