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Fujii Y, Tsugawa T, Fukuda Y, Adachi S, Honjo S, Akane Y, Kondo K, Sakai Y, Tanaka T, Sato T, Higasidate Y, Kubo N, Mori T, Kato S, Hamada R, Kikuchi M, Tahara Y, Nagai K, Ohara T, Yoshida M, Nakata S, Noguchi A, Kikuchi W, Hamada H, Tokutake-Hirose S, Fujimori M, Muramatsu M. Molecular evolutionary analysis of novel NSP4 mono-reassortant G1P[8]-E2 rotavirus strains that caused a discontinuous epidemic in Japan in 2015 and 2018. Front Microbiol 2024; 15:1430557. [PMID: 39050631 PMCID: PMC11266183 DOI: 10.3389/fmicb.2024.1430557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Accepted: 06/17/2024] [Indexed: 07/27/2024] Open
Abstract
In the 2010s, several unusual rotavirus strains emerged, causing epidemics worldwide. This study reports a comprehensive molecular epidemiological study of rotaviruses in Japan based on full-genome analysis. From 2014 to 2019, a total of 489 rotavirus-positive stool specimens were identified, and the associated viral genomes were analyzed by next-generation sequencing. The genotype constellations of those strains were classified into nine patterns (G1P[8] (Wa), G1P[8]-E2, G1P[8] (DS-1), G2P[4] (DS-1), G3P[8] (Wa), G3P[8] (DS-1), G8P[8] (DS-1), G9P[8] (Wa), and G9P[8]-E2). The major prevalent genotype differed by year, comprising G8P[8] (DS-1) (37% of that year's isolates) in 2014, G1P[8] (DS-1) (65%) in 2015, G9P[8] (Wa) (72%) in 2016, G3P[8] (DS-1) (66%) in 2017, G1P[8]-E2 (53%) in 2018, and G9P[8] (Wa) (26%) in 2019. The G1P[8]-E2 strains (G1-P[8]-I1-R1-C1-M1-A1-N1-T1-E2-H1) isolated from a total of 42 specimens in discontinuous years (2015 and 2018), which were the newly-emerged NSP4 mono-reassortant strains. Based on the results of the Bayesian evolutionary analyses, G1P[8]-E2 and G9P[8]-E2 were hypothesized to have been generated from distinct independent inter-genogroup reassortment events. The G1 strains detected in this study were classified into multiple clusters, depending on the year of detection. A comparison of the predicted amino acid sequences of the VP7 epitopes revealed that the G1 strains detected in different years encoded VP7 epitopes harboring distinct mutations. These mutations may be responsible for immune escape and annual changes in the prevalent strains.
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Affiliation(s)
- Yoshiki Fujii
- Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Takeshi Tsugawa
- Department of Pediatrics, Sapporo Medical University School of Medicine, Hokkaido, Japan
| | - Yuya Fukuda
- Department of Pediatrics, Sapporo Medical University School of Medicine, Hokkaido, Japan
| | - Shuhei Adachi
- Department of Pediatrics, Sapporo Medical University School of Medicine, Hokkaido, Japan
| | - Saho Honjo
- Department of Pediatrics, Sapporo Medical University School of Medicine, Hokkaido, Japan
| | - Yusuke Akane
- Department of Pediatrics, Sapporo Medical University School of Medicine, Hokkaido, Japan
| | - Kenji Kondo
- Department of Pediatrics, Sapporo Medical University School of Medicine, Hokkaido, Japan
| | - Yoshiyuki Sakai
- Department of Pediatrics, Hakodate Municipal Hospital, Hokkaido, Japan
| | - Toju Tanaka
- Department of Pediatrics, National Hospital Organization Hokkaido Medical Center, Hokkaido, Japan
| | - Toshiya Sato
- Department of Pediatrics, Iwamizawa Municipal General Hospital, Hokkaido, Japan
| | - Yoshihito Higasidate
- Department of Pediatrics, Japan Community Health Care Organization Sapporo Hokushin Hospital, Hokkaido, Japan
| | - Noriaki Kubo
- Department of Pediatrics, Japan Red Cross Urakawa Hospital, Hokkaido, Japan
| | - Toshihiko Mori
- Department of Pediatrics, NTT Medical Center Sapporo, Hokkaido, Japan
| | - Shinsuke Kato
- Department of Pediatrics, Rumoi City Hospital, Hokkaido, Japan
| | - Ryo Hamada
- Department of Pediatrics, Rumoi City Hospital, Hokkaido, Japan
| | - Masayoshi Kikuchi
- Department of Pediatrics, Sunagawa City Medical Center, Hokkaido, Japan
| | - Yasuo Tahara
- Department of Pediatrics, Steel Memorial Muroran Hospital, Hokkaido, Japan
| | - Kazushige Nagai
- Department of Pediatrics, Takikawa Municipal Hospital, Hokkaido, Japan
| | - Toshio Ohara
- Department of Pediatrics, Tomakomai City Hospital, Hokkaido, Japan
| | - Masaki Yoshida
- Department of Pediatrics, Yakumo General Hospital, Hokkaido, Japan
| | | | - Atsuko Noguchi
- Department of Pediatrics, Akita University Graduate School of Medicine, Akita, Japan
| | - Wakako Kikuchi
- Department of Pediatrics, Akita University Graduate School of Medicine, Akita, Japan
| | - Hiromichi Hamada
- Department of Pediatrics, Tokyo Women's Medical University Yachiyo Medical Center, Chiba, Japan
| | - Shoko Tokutake-Hirose
- Department of Pediatrics, Tokyo Women's Medical University Yachiyo Medical Center, Chiba, Japan
| | - Makoto Fujimori
- Department of Pediatrics, Tokyo Women's Medical University Yachiyo Medical Center, Chiba, Japan
| | - Masamichi Muramatsu
- Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan
- Department of Infectious Disease Research, Institute of Biomedical Research and Innovation, Foundation for Biomedical Research and Innovation at Kobe, Hyogo, Japan
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2
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Mwangi PN, Potgieter RL, Uwimana J, Mutesa L, Muganga N, Murenzi D, Tusiyenge L, Mwenda JM, Mogotsi MT, Rakau K, Esona MD, Steele AD, Seheri ML, Nyaga MM. The Evolution of Post-Vaccine G8P[4] Group a Rotavirus Strains in Rwanda; Notable Variance at the Neutralization Epitope Sites. Pathogens 2023; 12:658. [PMID: 37242329 PMCID: PMC10223037 DOI: 10.3390/pathogens12050658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 04/24/2023] [Accepted: 04/26/2023] [Indexed: 05/28/2023] Open
Abstract
Africa has a high level of genetic diversity of rotavirus strains, which is suggested to be a possible reason contributing to the suboptimal effectiveness of rotavirus vaccines in this region. One strain that contributes to this rotavirus diversity in Africa is the G8P[4]. This study aimed to elucidate the entire genome and evolution of Rwandan G8P[4] strains. Illumina sequencing was performed for twenty-one Rwandan G8P[4] rotavirus strains. Twenty of the Rwandan G8P[4] strains had a pure DS-1-like genotype constellation, and one strain had a reassortant genotype constellation. Notable radical amino acid differences were observed at the neutralization sites when compared with cognate regions in vaccine strains potentially playing a role in neutralization escape. Phylogenetic analysis revealed that the closest relationship was with East African human group A rotavirus (RVA) strains for five of the genome segments. Two genome sequences of the NSP4 genome segment were closely related to bovine members of the DS-1-like family. Fourteen VP1 and eleven VP3 sequences had the closest relationships with the RotaTeq™ vaccine WC3 bovine genes. These findings suggest that the evolution of VP1 and VP3 might have resulted from reassortment events with RotaTeq™ vaccine WC3 bovine genes. The close phylogenetic relationship with East African G8P[4] strains from Kenya and Uganda suggests co-circulation in these countries. These findings highlight the need for continued whole-genomic surveillance to elucidate the evolution of G8P[4] strains, especially after the introduction of rotavirus vaccination.
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Affiliation(s)
- Peter N. Mwangi
- Next Generation Sequencing Unit, Division of Virology, Faculty of Health Sciences, University of the Free State, Bloemfontein 9300, South Africa
| | - Robyn-Lee Potgieter
- Next Generation Sequencing Unit, Division of Virology, Faculty of Health Sciences, University of the Free State, Bloemfontein 9300, South Africa
| | - Jeannine Uwimana
- Kigali University Teaching Hospital, College of Medicine and Health Sciences, University of Rwanda, Kigali P.O. Box 4285, Rwanda
| | - Leon Mutesa
- Kigali University Teaching Hospital, College of Medicine and Health Sciences, University of Rwanda, Kigali P.O. Box 4285, Rwanda
- Centre for Human Genetics, College of Medicine and Health Sciences, University of Rwanda, Kigali P.O. Box 4285, Rwanda
| | - Narcisse Muganga
- Kigali University Teaching Hospital, College of Medicine and Health Sciences, University of Rwanda, Kigali P.O. Box 4285, Rwanda
| | - Didier Murenzi
- Kigali University Teaching Hospital, College of Medicine and Health Sciences, University of Rwanda, Kigali P.O. Box 4285, Rwanda
| | - Lisine Tusiyenge
- Kigali University Teaching Hospital, College of Medicine and Health Sciences, University of Rwanda, Kigali P.O. Box 4285, Rwanda
| | - Jason M. Mwenda
- World Health Organization, Regional Office for Africa, Brazzaville P.O. Box 06, Congo
| | - Milton T. Mogotsi
- Next Generation Sequencing Unit, Division of Virology, Faculty of Health Sciences, University of the Free State, Bloemfontein 9300, South Africa
| | - Kebareng Rakau
- Diarrhoeal Pathogens Research Unit, Sefako Makgatho Health Sciences University (MEDUNSA), Pretoria 0204, South Africa
| | - Mathew D. Esona
- Diarrhoeal Pathogens Research Unit, Sefako Makgatho Health Sciences University (MEDUNSA), Pretoria 0204, South Africa
| | - A. Duncan Steele
- Diarrhoeal Pathogens Research Unit, Sefako Makgatho Health Sciences University (MEDUNSA), Pretoria 0204, South Africa
| | - Mapaseka L. Seheri
- Diarrhoeal Pathogens Research Unit, Sefako Makgatho Health Sciences University (MEDUNSA), Pretoria 0204, South Africa
| | - Martin M. Nyaga
- Next Generation Sequencing Unit, Division of Virology, Faculty of Health Sciences, University of the Free State, Bloemfontein 9300, South Africa
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3
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Makori TO, Bargul JL, Lambisia AW, Mwanga MJ, Murunga N, de Laurent ZR, Lewa CS, Mutunga M, Kellam P, Cotten M, Nokes DJ, Phan M, Agoti CN. Genomic epidemiology of the rotavirus G2P[4] strains in coastal Kenya pre- and post-rotavirus vaccine introduction, 2012-8. Virus Evol 2023; 9:vead025. [PMID: 37207000 PMCID: PMC10190042 DOI: 10.1093/ve/vead025] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 03/07/2023] [Accepted: 04/14/2023] [Indexed: 05/21/2023] Open
Abstract
The introduction of rotavirus vaccines into the national immunization programme in many countries has led to a decline in childhood diarrhoea disease burden. Coincidentally, the incidence of some rotavirus group A (RVA) genotypes has increased, which may result from non-vaccine-type replacement. Here, we investigate the evolutionary genomics of rotavirus G2P[4] which has shown an increase in countries that introduced the monovalent Rotarix® vaccine. We examined sixty-three RVA G2P[4] strains sampled from children (aged below 13 years) admitted to Kilifi County Hospital, coastal Kenya, pre- (2012 to June 2014) and post-(July 2014 to 2018) rotavirus vaccine introduction. All the sixty-three genome sequences showed a typical DS-1-like genome constellation (G2-P[4]-I2-R2-C2-M2-A2-N2-T2-E2-H2). Pre-vaccine G2 sequences predominantly classified as sub-lineage IVa-3 and co-circulated with low numbers of sub-lineage IVa-1 strains, whereas post-vaccine G2 sequences mainly classified into sub-lineage IVa-3. In addition, in the pre-vaccine period, P[4] sub-lineage IVa strains co-circulated with low numbers of P[4] lineage II strains, but P[4] sub-lineage IVa strains predominated in the post-vaccine period. On the global phylogeny, the Kenyan pre- and post-vaccine G2P[4] strains clustered separately, suggesting that different virus populations circulated in the two periods. However, the strains from both periods exhibited conserved amino acid changes in the known antigenic epitopes, suggesting that replacement of the predominant G2P[4] cluster was unlikely a result of immune escape. Our findings demonstrate that the pre- and post-vaccine G2P[4] strains circulating in Kilifi, coastal Kenya, differed genetically but likely were antigenically similar. This information informs the discussion on the consequences of rotavirus vaccination on rotavirus diversity.
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Affiliation(s)
- Timothy O Makori
- Epidemiology and Demography Department Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Off Hospital Road, P.O BOX 230-80108, Kilifi, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Kalimoni, PO Box 62000-00200, Juja, Kenya
| | - Joel L Bargul
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Kalimoni, PO Box 62000-00200, Juja, Kenya
- International Centre of Insect Physiology and Ecology, Animal Health Theme, ICIPE Road Kasarani, P.O BOX 30772-00100, Nairobi, Kenya
| | - Arnold W Lambisia
- Epidemiology and Demography Department Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Off Hospital Road, P.O BOX 230-80108, Kilifi, Kenya
| | - Mike J Mwanga
- Epidemiology and Demography Department Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Off Hospital Road, P.O BOX 230-80108, Kilifi, Kenya
| | - Nickson Murunga
- Epidemiology and Demography Department Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Off Hospital Road, P.O BOX 230-80108, Kilifi, Kenya
| | - Zaydah R de Laurent
- Epidemiology and Demography Department Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Off Hospital Road, P.O BOX 230-80108, Kilifi, Kenya
| | - Clement S Lewa
- Epidemiology and Demography Department Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Off Hospital Road, P.O BOX 230-80108, Kilifi, Kenya
| | - Martin Mutunga
- Epidemiology and Demography Department Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Off Hospital Road, P.O BOX 230-80108, Kilifi, Kenya
| | - Paul Kellam
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, Exhibition Road, London SW7 2AZ, UK
- Kymab Ltd, The Bennet Building (B930), Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Matthew Cotten
- Medical Research Centre (MRC)/Uganda Virus Research Institute, Plot No: 51-59 Nakiwogo Road, P.O.Box 49, Entebbe, Uganda
- MRC-University of Glasgow, Centre for Virus Research Glasgow, 464 Bearsden Road, Glasgow G61 1QH UK
| | - D James Nokes
- Epidemiology and Demography Department Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Off Hospital Road, P.O BOX 230-80108, Kilifi, Kenya
- School of Life Sciences and Zeeman Institute (SBIDER), The University of Warwick, Gibbet Hill Campus, Coventry CV4 7AL, UK
| | - My Phan
- Medical Research Centre (MRC)/Uganda Virus Research Institute, Plot No: 51-59 Nakiwogo Road, P.O.Box 49, Entebbe, Uganda
- MRC-University of Glasgow, Centre for Virus Research Glasgow, 464 Bearsden Road, Glasgow G61 1QH UK
| | - Charles N Agoti
- Epidemiology and Demography Department Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Off Hospital Road, P.O BOX 230-80108, Kilifi, Kenya
- School of Health and Human Sciences, Pwani University, Kilifi-Malindi Road, P.O BOX 195-80108, Kilifi, Kenya
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4
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Mwangi PN, Potgieter RL, Simwaka J, Mpabalwani EM, Mwenda JM, Mogotsi MT, Magagula N, Esona MD, Steele AD, Seheri ML, Nyaga MM. Genomic Analysis of G2P[4] Group A Rotaviruses in Zambia Reveals Positive Selection in Amino Acid Site 7 of Viral Protein 3. Viruses 2023; 15:v15020501. [PMID: 36851715 PMCID: PMC9965253 DOI: 10.3390/v15020501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 02/07/2023] [Accepted: 02/09/2023] [Indexed: 02/15/2023] Open
Abstract
The G2P[4] genotype is among the rotavirus strains that circulate commonly in humans. Several countries have reported its immediate upsurge after the introduction of rotavirus vaccination, raising concern about sub-optimal vaccine effectiveness against this genotype in the long term. This study aimed to gain insight into the evolution of post-vaccine Zambian G2P[4] group A rotavirus (RVA) strains and their overall genetic make-up by analysis of sequence alignments at the amino acid (AA) level. Twenty-nine Zambian G2P[4] rotavirus strains were subjected to whole-genome sequencing using the Illumina MiSeq® platform. All the strains exhibited the typical DS-1-like genotype constellation, and the nucleotide sequences of the 11 genome segments showed high nucleotide similarities (>97%). Phylogenetic analyses together with representative global G2P[4] RVA showed that Zambian strains clustered into human lineages IV (for VP2, VP4, VP7, NSP1, and NSP5), V (for VP1, VP3, VP6, NSP2, and NSP3), and XXIII (for NSP4). The AA differences between the lineages where the study strains clustered and lineages of global reference strains were identified and analyzed. Selection pressure analysis revealed that AA site seven in the Viral Protein 3 (VP3) genome segment was under positive selection. This site occurs in the region of intrinsic disorder in the VP3 protein, and Zambian G2P[4] strains could potentially be utilizing this intrinsically disordered region to survive immune pressure. The Zambian G2P[4] strains from 2012 to 2016 comprised the G2P[4] strains that have been circulating globally since the early 2000s, highlighting the epidemiological fitness of these contemporary G2P[4] strains. Continuous whole-genome surveillance of G2P[4] strains remains imperative to understand their evolution during the post-vaccination period.
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Affiliation(s)
- Peter N. Mwangi
- Next Generation Sequencing Unit and Division of Virology, Faculty of Health Sciences, University of the Free State, Bloemfontein 9300, South Africa
| | - Robyn-Lee Potgieter
- Next Generation Sequencing Unit and Division of Virology, Faculty of Health Sciences, University of the Free State, Bloemfontein 9300, South Africa
| | - Julia Simwaka
- Institute of Basic and Biomedical Sciences, Department of Biomedical Sciences, The Levy Mwanawasa Medical University, Lusaka 10101, Zambia
| | - Evans M. Mpabalwani
- Department of Paediatrics and Child Health, School of Medicine, University of Zambia, Ridgeway, Lusaka RW50000, Zambia
| | - Jason M. Mwenda
- World Health Organization, Regional Office for Africa, Brazzaville P.O. Box 06, Congo
| | - Milton T. Mogotsi
- Next Generation Sequencing Unit and Division of Virology, Faculty of Health Sciences, University of the Free State, Bloemfontein 9300, South Africa
| | - Nonkululeko Magagula
- Diarrheal Pathogens Research Unit, Faculty of Health Sciences, Sefako Makgatho Health Sciences University, Pretoria 0204, South Africa
| | - Mathew D. Esona
- Diarrheal Pathogens Research Unit, Faculty of Health Sciences, Sefako Makgatho Health Sciences University, Pretoria 0204, South Africa
| | - A. Duncan Steele
- Diarrheal Pathogens Research Unit, Faculty of Health Sciences, Sefako Makgatho Health Sciences University, Pretoria 0204, South Africa
| | - Mapaseka L. Seheri
- Diarrheal Pathogens Research Unit, Faculty of Health Sciences, Sefako Makgatho Health Sciences University, Pretoria 0204, South Africa
| | - Martin M. Nyaga
- Next Generation Sequencing Unit and Division of Virology, Faculty of Health Sciences, University of the Free State, Bloemfontein 9300, South Africa
- Correspondence:
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5
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Zhang T, Li J, Jiang YZ, Xu JQ, Guan XH, Wang LQ, Chen J, Liang Y. Genotype Distribution and Evolutionary Analysis of Rotavirus Associated with Acute Diarrhea Outpatients in Hubei, China, 2013–2016. Virol Sin 2022; 37:503-512. [PMID: 35643410 PMCID: PMC9437618 DOI: 10.1016/j.virs.2022.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 05/17/2022] [Indexed: 11/23/2022] Open
Abstract
Group A human rotaviruses (RVAs) annually cause the deaths of 215,000 infants and young children. To understand the epidemiological characteristics and genetic evolution of RVAs, we performed sentinel surveillance on RVA prevalence in a rotavirus-surveillance network in Hubei, China. From 2013 to 2016, a total of 2007 fecal samples from hospital outpatients with acute gastroenteritis were collected from four cities of Hubei Province. Of the 2007 samples, 153 (7.62%) were identified positive for RVA by real-time RT-PCR. RVA infection in Hubei mainly occurred in autumn and winter. The highest detection rate of RVA infection was in 1–2 years old of outpatients (16.97%). No significant difference of RVA positive rate was observed between females and males. We performed a phylogenetic analysis of the G/P genotypes based on the partial VP7/VP4 gene sequences of RVAs. G9P[8] was the most predominant strain in all four years but the prevalence of G2P[4] genotype increased rapidly since 2014. We reconstructed the evolutionary time scale of RVAs in Hubei, and found that the evolutionary rates of the G9, G2, P[8], and P[4] genotypes of RVA were 1.069 × 10−3, 1.029 × 10−3, 1.283 × 10−3 and 1.172 × 10−3 nucleotide substitutions/site/year, respectively. Importantly, using a molecular clock model, we showed that most G9, G2, P[8], and P[4] genotype strains dated from the recent ancestor in 2005, 2005, 1993, and 2013, respectively. The finding of the distribution of RVAs in infants and young children in Hubei Province will contribute to the understanding of the epidemiological characteristics and genetic evolution of RVAs in China. A four-year study of sentinel surveillance program of RVAs was performed in Hubei, China. The key population of rotavirus infection is 1–2 years old of outpatients with acute gastroenteritis. G9P[8] was the most predominant strain between 2013 and 2016. The estimating time to the most recent common ancestor for the G9 genotype based on partial VP7 gene was 46 years. RVA distribution in Hubei Province contributes to the understanding of the epidemiological characteristics of RVAs in China.
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6
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Mwangi PN, Page NA, Seheri ML, Mphahlele MJ, Nadan S, Esona MD, Kumwenda B, Kamng'ona AW, Donato CM, Steele DA, Ndze VN, Dennis FE, Jere KC, Nyaga MM. Evolutionary changes between pre- and post-vaccine South African group A G2P[4] rotavirus strains, 2003-2017. Microb Genom 2022; 8. [PMID: 35446251 PMCID: PMC9453071 DOI: 10.1099/mgen.0.000809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The transient upsurge of G2P[4] group A rotavirus (RVA) after Rotarix vaccine introduction in several countries has been a matter of concern. To gain insight into the diversity and evolution of G2P[4] strains in South Africa pre- and post-RVA vaccination introduction, whole-genome sequencing was performed for RVA positive faecal specimens collected between 2003 and 2017 and samples previously sequenced were obtained from GenBank (n=103; 56 pre- and 47 post-vaccine). Pre-vaccine G2 sequences predominantly clustered within sub-lineage IVa-1. In contrast, post-vaccine G2 sequences clustered mainly within sub-lineage IVa-3, whereby a radical amino acid (AA) substitution, S15F, was observed between the two sub-lineages. Pre-vaccine P[4] sequences predominantly segregated within sub-lineage IVa while post-vaccine sequences clustered mostly within sub-lineage IVb, with a radical AA substitution R162G. Both S15F and R162G occurred outside recognised antigenic sites. The AA residue at position 15 is found within the signal sequence domain of Viral Protein 7 (VP7) involved in translocation of VP7 into endoplasmic reticulum during infection process. The 162 AA residue lies within the hemagglutination domain of Viral Protein 4 (VP4) engaged in interaction with sialic acid-containing structure during attachment to the target cell. Free energy change analysis on VP7 indicated accumulation of stable point mutations in both antigenic and non-antigenic regions. The segregation of South African G2P[4] strains into pre- and post-vaccination sub-lineages is likely due to erstwhile hypothesized stepwise lineage/sub-lineage evolution of G2P[4] strains rather than RVA vaccine introduction. Our findings reinforce the need for continuous whole-genome RVA surveillance and investigation of contribution of AA substitutions in understanding the dynamic G2P[4] epidemiology.
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Affiliation(s)
- Peter N Mwangi
- Next Generation Sequencing Unit and Division of Virology, Faculty of Health Sciences, University of the Free State, Bloemfontein 9300, South Africa
| | - Nicola A Page
- Centre for Enteric Disease, National Institute for Communicable Diseases, Private Bag X4, Sandringham, 2131, Johannesburg, South Africa.,Department of Medical Virology, Faculty of Health Sciences, University of Pretoria, Private Bag X323, Arcadia, 0007, Pretoria, South Africa
| | - Mapaseka L Seheri
- Diarrheal Pathogens Research Unit, Sefako Makgatho Health Sciences University, Medunsa 0204, Pretoria, South Africa
| | - M Jeffrey Mphahlele
- Diarrheal Pathogens Research Unit, Sefako Makgatho Health Sciences University, Medunsa 0204, Pretoria, South Africa.,Office of the Deputy Vice Chancellor for Research and Innovation, North-West University, Potchefstroom 2351, South Africa.,South African Medical Research Council, Pretoria 0001, South Africa
| | - Sandrama Nadan
- Centre for Enteric Disease, National Institute for Communicable Diseases, Private Bag X4, Sandringham, 2131, Johannesburg, South Africa
| | - Mathew D Esona
- Diarrheal Pathogens Research Unit, Sefako Makgatho Health Sciences University, Medunsa 0204, Pretoria, South Africa
| | - Benjamin Kumwenda
- Department of Biomedical Sciences, School of Life Sciences and Applied Health Professions, Kamuzu University of Health Sciences, Private Bag 360, Chichiri, Blantyre 3, Malawi
| | - Arox W Kamng'ona
- Department of Biomedical Sciences, School of Life Sciences and Applied Health Professions, Kamuzu University of Health Sciences, Private Bag 360, Chichiri, Blantyre 3, Malawi
| | - Celeste M Donato
- Department of Medical Laboratory Sciences, School of Life Sciences and Applied Health Professions, Kamuzu University of Health Sciences, Private Bag 360, Chichiri, Blantyre3, Malawi.,Enteric Diseases Group, Murdoch Children's Research Institute, 50 Flemington Road, Parkville, Melboune 3052, Australia.,Department of Paediatrics, the University of Melbourne, Parkville 3010, Australia
| | - Duncan A Steele
- Diarrheal Pathogens Research Unit, Sefako Makgatho Health Sciences University, Medunsa 0204, Pretoria, South Africa
| | - Valantine N Ndze
- Faculty of Health Sciences, University of Buea, P.O Box 63 Buea, Cameroon
| | - Francis E Dennis
- Department of Electron Microscopy and Histopathology, Noguchi Memorial Institute for Medical Research, University of Ghana, P.O Box LG581, Legon, Ghana
| | - Khuzwayo C Jere
- Center for Global Vaccine Research, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, L697BE, Liverpool, UK.,Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre 312225, Malawi
| | - Martin M Nyaga
- Next Generation Sequencing Unit and Division of Virology, Faculty of Health Sciences, University of the Free State, Bloemfontein 9300, South Africa
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7
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Sadiq A, Bostan N, Aziz A. Effect of rotavirus genetic diversity on vaccine impact. Rev Med Virol 2022; 32:e2259. [PMID: 34997676 DOI: 10.1002/rmv.2259] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 05/05/2021] [Indexed: 11/07/2022]
Abstract
Group A rotaviruses (RVAs) are the leading cause of gastroenteritis, causing 0.2 million deaths and several million hospitalisations globally each year. Four rotavirus vaccines (RotarixTM , RotaTeqTM , Rotavac® and ROTASIIL® ) have been pre-qualified by the World Health Organization (WHO), but the two newly pre-qualified vaccines (Rotavac® and ROTASIIL® ) are currently only in use in Palestine and India, respectively. In 2009, WHO strongly proposed that rotavirus vaccines be included in the routine vaccination schedule of all countries around the world. By the end of 2019, a total of 108 countries had administered rotavirus vaccines, and 10 countries have currently been approved by Gavi for the introduction of rotavirus vaccine in the near future. With 39% of global coverage, rotavirus vaccines have had a substantial effect on diarrhoeal morbidity and mortality in different geographical areas, although efficacy appears to be higher in high income settings. Due to the segmented RNA genome, the pattern of RVA genotypes in the human population is evolving through interspecies transmission and/or reassortment events for which the vaccine might be less effective in the future. However, despite the relative increase in some particular genotypes after rotavirus vaccine use, the overall efficacy of rotavirus mass vaccination worldwide has not been affected. Some of the challenges to improve the effect of current rotavirus vaccines can be solved in the future by new rotavirus vaccines and by vaccines currently in progress.
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Affiliation(s)
- Asma Sadiq
- Department of Biosciences, Molecular Virology Laboratory, COMSATS University, Islamabad, Pakistan
| | - Nazish Bostan
- Department of Biosciences, Molecular Virology Laboratory, COMSATS University, Islamabad, Pakistan
| | - Aamir Aziz
- Sarhad University of Science and Information Technology, Institute of Biological Sciences, Sarhad University, Peshawar, Pakistan
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Morozova OV, Sashina TA, Epifanova NV, Kashnikov AY, Novikova NA. Increasing detection of rotavirus G2P[4] strains in Nizhny Novgorod, Russia, between 2016 and 2019. Arch Virol 2020; 166:115-124. [PMID: 33079276 DOI: 10.1007/s00705-020-04853-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 09/10/2020] [Indexed: 01/28/2023]
Abstract
Rotavirus infection is one of the leading causes of acute gastroenteritis in children in their first years of life. We studied the genotypic diversity of rotavirus A (RVA) strains in Nizhny Novgorod, Russia, during the period 2016-19. In total, 4714 samples of faeces from children admitted to the Nizhny Novgorod Hospital for Infectious Diseases with acute gastroenteritis were examined. The share of rotavirus-positive samples was 31.5% in 2016-17. It decreased to 21.6% in 2018-19. In Nizhny Novgorod, all six global types of RVA were detected (G1P[8], G2P[4], G3P[8], G4P[8], G9P[8] and G12P[8]), as well as sporadic samples with genotypes G9P[4], G3P[9], G9P[9], G8P[8], G2P[8], G4P[4], G3P[9]. The fraction of strains with genotype G2P[4] gradually increased from 5.9% in 2016-17 to 39.1% in 2018-19. Simultaneously, the proportion of G9P[8] strains decreased from 63.2% to 27.7% in the same period. Phylogenetic analysis showed that rotaviruses with the G2P[4] genotype carried ubiquitous alleles of the VP7 and VP4 genes during the period of their prevalence: G2-IVa-1 and G2-IVa-3; P[4]-IVa and P[4]-IVb. As rotavirus vaccination is not widely used in the region because it is not included in the national vaccination calendar in Russia so far, the increase in the number of G2P[4] RVA is likely due to natural strain fluctuations.
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Affiliation(s)
- Olga V Morozova
- I.N. Blokhina Nizhny Novgorod Research Institute of Epidemiology and Microbiology, 71 Malaya Yamskaya Str., Nizhny Novgorod, Russian Federation, 603950.
| | - Tatiana A Sashina
- I.N. Blokhina Nizhny Novgorod Research Institute of Epidemiology and Microbiology, 71 Malaya Yamskaya Str., Nizhny Novgorod, Russian Federation, 603950
| | - Natalia V Epifanova
- I.N. Blokhina Nizhny Novgorod Research Institute of Epidemiology and Microbiology, 71 Malaya Yamskaya Str., Nizhny Novgorod, Russian Federation, 603950
| | - Alexander Yu Kashnikov
- I.N. Blokhina Nizhny Novgorod Research Institute of Epidemiology and Microbiology, 71 Malaya Yamskaya Str., Nizhny Novgorod, Russian Federation, 603950
| | - Nadezhda A Novikova
- I.N. Blokhina Nizhny Novgorod Research Institute of Epidemiology and Microbiology, 71 Malaya Yamskaya Str., Nizhny Novgorod, Russian Federation, 603950
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Dynamics of G2P[4] strain evolution and rotavirus vaccination: A review of evidence for Rotarix. Vaccine 2020; 38:5591-5600. [PMID: 32651115 DOI: 10.1016/j.vaccine.2020.06.059] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 06/11/2020] [Accepted: 06/19/2020] [Indexed: 12/27/2022]
Abstract
Rotavirus (RV) gastroenteritis is a vaccine-preventable disease that creates high medical and economic burden in both developed and developing countries. Worldwide, more than 100 countries have introduced RV vaccines in their national immunization programs, and the remarkable impact of reducing the burden of severe childhood gastroenteritis has been unequivocally demonstrated. Currently, 2 oral vaccines (Rotarix, GSK and RotaTeq, Merck) are widely utilized. Recent temporary increases in the relative prevalence of G2P[4] RV strains have been observed in countries implementing RV vaccination. This comprehensive literature review aims to provide an insight on RV genotype evolution in the context of mass vaccination with Rotarix, particularly in the case of G2P[4]. In the post-vaccine era, strain surveillance data indicated temporal and spatial changes in countries both with and without RV vaccination programs. Annual fluctuations in G2P[4] prevalence seem to occur naturally, with no substantial differences between countries using Rotarix, RotaTeq or mixed vaccination programs. Moreover, Rotarix has been shown to be efficacious and effective against gastroenteritis caused by non-vaccine strains, including G2P[4]. These data indicate that shifts in RV genotype distribution are likely to constitute an inherent process of virus evolution to infect the human gut. Following RV vaccine introduction, incidences of RV gastroenteritis declined dramatically and mass vaccination will likely maintain this status, despite possible fluctuations in the relative distribution of genotypes. There is no conclusive evidence of unusual burst of new or vaccine-escape strains since global RV vaccines use. The emergence of strains with a potential to increase the current burden of RV disease should be continuously monitored and can only be established by exhaustive characterization of strains, including whole genomic sequencing. Given the natural fluctuations in RV strains over time, caution is advised when interpreting temporal changes in RV strain dynamics, as they could mistakenly be attributed to vaccination.
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Sub-genotype phylogeny of the non-G, non-P genes of genotype 2 Rotavirus A strains. PLoS One 2019; 14:e0217422. [PMID: 31150425 PMCID: PMC6544246 DOI: 10.1371/journal.pone.0217422] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 05/10/2019] [Indexed: 12/11/2022] Open
Abstract
Recent increase in the detection of unusual G1P[8], G3P[8], G8P[8], and G9P[4] Rotavirus A (RVA) strains bearing the DS-1-like constellation of the non-G, non-P genes (hereafter referred to as the genotype 2 backbone) requires better understanding of their evolutionary relationship. However, within a genotype, there is lack of a consensus lineage designation framework and a set of common sequences that can serve as references. Phylogenetic analyses were carried out on over 8,500 RVA genotype 2 genes systematically retrieved from the rotavirus database within the NCBI Virus Variation Resource. In line with previous designations, using pairwise comparison of cogent nucleotide sequences and stringent bootstrap support, reference lineages were defined. This study proposes a lineage framework and provides a dataset ranging from 34 to 145 sequences for each genotype 2 gene for orderly lineage designation of global genotype 2 genes of RVAs detected in human and animals. The framework identified five to 31 lineages depending on the gene. The least number of lineages (five to seven) were observed in genotypes A2 (NSP1), T2 (NSP3) and H2 (NSP5) which are limited to human RVA whereas the most number of lineages (31) was observed in genotype E2 (NSP4). Sharing of the same lineage constellations of the genotype 2 backbone genes between recently-emerging, unusual G1P[8], G3P[8], G8P[8] and G9P[4] reassortants and many contemporary G2P[4] strains provided strong support to the hypothesis that unusual genotype 2 strains originated primarily from reassortment events in the recent past involving contemporary G2P[4] strains as one parent and ordinary genotype 1 strains or animal RVA strains as the other. The lineage framework with selected reference sequences will help researchers to identify the lineage to which a given genotype 2 strain belongs, and trace the evolutionary history of common and unusual genotype 2 strains in circulation.
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Strydom A, Motanyane L, Nyaga MM, João ED, Cuamba A, Mandomando I, Cassocera M, de Deus N, O'Neill H. Whole-genome characterization of G12 rotavirus strains detected in Mozambique reveals a co-infection with a GXP[14] strain of possible animal origin. J Gen Virol 2019; 100:932-937. [PMID: 31140967 DOI: 10.1099/jgv.0.001270] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
A high prevalence of G12 rotavirus strains has previously been reported in southern Mozambique. In this study, the full genomes of five Mozambican G12 strains were determined directly from stool using an Illumina Miseq platform. One sample (0060) contained an intergenogroup co-infection of a G12P[8] Wa-like strain and a GXP[14] DS-1-like strain. The sequences of seven genome segments, detected for the GXP[14] strain, clustered with a diverse group of mostly animal strains, suggesting co-infection with a strain of possible animal origin. The stool samples contained G12P[6] rotavirus strains with Wa-like backbones. Phylogenetic analyses of the VP4 and VP7 encoding segments of the G12P[6] strains suggested that they were reassortants containing backbones that are similar to that of the G12P[8] strain. The study confirms previous observations of interspecies transmission and emphasizes the importance of whole-genome sequencing in order to evaluate rotavirus co-infections and reassortants.
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Affiliation(s)
- Amy Strydom
- 1 Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa
| | - Lithabiso Motanyane
- 1 Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa
| | - Martin M Nyaga
- 2 Next Generation Sequencing Unit, Department of Medical Virology, Faculty of Health Sciences, University of the Free State, Bloemfontein, South Africa
| | - Eva Dora João
- 3 Centro de Investigação em Saúde de Manhiça (CISM), Manhiça, Mozambique.,4 Institute of Hygiene and Tropical Medicine, Lisbon, Portugal
| | - Assa Cuamba
- 5 Faculdade de Medicina, Universidade Eduardo Mondlane, Maputo, Mozambique
| | - Inácio Mandomando
- 3 Centro de Investigação em Saúde de Manhiça (CISM), Manhiça, Mozambique.,6 Instituto Nacional de Saúde, Maputo, Mozambique
| | - Marta Cassocera
- 3 Centro de Investigação em Saúde de Manhiça (CISM), Manhiça, Mozambique
| | | | - Hester O'Neill
- 1 Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa
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12
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Strydom A, João ED, Motanyane L, Nyaga MM, Christiaan Potgieter A, Cuamba A, Mandomando I, Cassocera M, de Deus N, O'Neill HG. Whole genome analyses of DS-1-like Rotavirus A strains detected in children with acute diarrhoea in southern Mozambique suggest several reassortment events. INFECTION GENETICS AND EVOLUTION 2019; 69:68-75. [PMID: 30641151 DOI: 10.1016/j.meegid.2019.01.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 01/10/2019] [Accepted: 01/10/2019] [Indexed: 11/20/2022]
Abstract
We report the first whole genome constellations of Mozambican rotavirus A strains detected between 2012 and 2013 in the Mavalane General Hospital in Maputo city and Manhiça District Hospital in the Manhiça district. Consensus sequences for ten DS-1-like strains (G2P[4] and G8P[4]) were identified with an Illumina Miseq platform using cDNA prepared from dsRNA extracted from stool samples, without genome amplification or prior adaptation to cell culture. Comparison of previously reported genotyping results and the consensus sequences described in this study, indicated that the genotype primers specific for G12 and P[4] might require revision. Phylogenetic analyses indicated diversity among the G2P[4] Mozambican strains and suggested reassortment between G2P[4] and G8P[4] Mozambican strains, as well as the intragenogroup reassortment of all the genome segments encoding VP1, 2, 3 and 6 for strain RVA/Human-wt/MOZ/0045/2012G8P[4]. These results highlight the necessity to determine whole genome constellations to confirm surveillance data in Africa and to monitor the growing diversity in DS-1-like strains.
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Affiliation(s)
- Amy Strydom
- Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa
| | - Eva Dora João
- Centro de Investigação em Saúde de Manhiça (CISM), Manhiça, Mozambique; Institute of Hygiene and Tropical Medicine, Lisbon, Portugal
| | - Lithabiso Motanyane
- Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa
| | - Martin M Nyaga
- Next Generation Sequencing Unit, Department of Medical Virology, Faculty of Health Sciences, University of the Free State, Bloemfontein, South Africa
| | - A Christiaan Potgieter
- Biochemistry, Focus Area Human Metabolomics, North-West University, Potchefstroom, South Africa; Deltamune (Pty.) Ltd., Lyttelton, Centurion, South Africa
| | - Assa Cuamba
- Faculdade de Medicina, Universidade Eduardo Mondlane, Maputo, Mozambique
| | - Inacio Mandomando
- Centro de Investigação em Saúde de Manhiça (CISM), Manhiça, Mozambique; Institute of Hygiene and Tropical Medicine, Lisbon, Portugal
| | - Marta Cassocera
- Centro de Investigação em Saúde de Manhiça (CISM), Manhiça, Mozambique
| | | | - Hester G O'Neill
- Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa.
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A Multiplex PCR/LDR Assay for Viral Agents of Diarrhea with the Capacity to Genotype Rotavirus. Sci Rep 2018; 8:13215. [PMID: 30181651 PMCID: PMC6123451 DOI: 10.1038/s41598-018-30301-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 07/27/2018] [Indexed: 12/11/2022] Open
Abstract
Rotavirus and noroviruses are major causes of diarrhea. Variable rotavirus vaccination efficacy in Africa and Asia is multifactorial, including the diversity of circulating strains and viral co-infection. We describe a multiplexed assay that detects and genotypes viruses from stool specimens. It includes a one-step reverse transcriptase PCR reaction, a ligase detection reaction (LDR), then hybridization of fluorescent products to micro-beads. In clinical samples it detects rotavirus, caliciviruses (sapovirus and norovirus), mixed infections, and genotypes or genogroups of rotaviruses and noroviruses, respectively. The assay also has the capacity to detect hepatitis A. The assay was validated on reference isolates and 296 stool specimens from the US and Ghana. The assay was 97% sensitive and 100% specific. The genogroup was concordant in 100% of norovirus, and the genotype in 91% and 89% of rotavirus G- and P-types, respectively. Two rare rotavirus strains, G6P[6] and G6P[8], were detected in stool specimens from Ghana. The high-throughput assay is sensitive, specific, and may be of utility in the epidemiological surveillance for rare and emerging viral strains post-rotavirus vaccine implementation.
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Hatcher EL, Zhdanov SA, Bao Y, Blinkova O, Nawrocki EP, Ostapchuck Y, Schäffer AA, Brister JR. Virus Variation Resource - improved response to emergent viral outbreaks. Nucleic Acids Res 2016; 45:D482-D490. [PMID: 27899678 PMCID: PMC5210549 DOI: 10.1093/nar/gkw1065] [Citation(s) in RCA: 264] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 10/20/2016] [Accepted: 10/28/2016] [Indexed: 02/01/2023] Open
Abstract
The Virus Variation Resource is a value-added viral sequence data resource hosted by the National Center for Biotechnology Information. The resource is located at http://www.ncbi.nlm.nih.gov/genome/viruses/variation/ and includes modules for seven viral groups: influenza virus, Dengue virus, West Nile virus, Ebolavirus, MERS coronavirus, Rotavirus A and Zika virus Each module is supported by pipelines that scan newly released GenBank records, annotate genes and proteins and parse sample descriptors and then map them to controlled vocabulary. These processes in turn support a purpose-built search interface where users can select sequences based on standardized gene, protein and metadata terms. Once sequences are selected, a suite of tools for downloading data, multi-sequence alignment and tree building supports a variety of user directed activities. This manuscript describes a series of features and functionalities recently added to the Virus Variation Resource.
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Affiliation(s)
- Eneida L Hatcher
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Sergey A Zhdanov
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Yiming Bao
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Olga Blinkova
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Eric P Nawrocki
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Yuri Ostapchuck
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Alejandro A Schäffer
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - J Rodney Brister
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
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