Genetic variation of prevalent G1P[8] human rotaviruses in South Korea

The human rotavirus G1P[8] strain is one of the most common rotaviruses worldwide, including Korea. Six Korean G1P[8] human rotaviruses, isolated using cell culture techniques, were characterized on the basis of sequence differences in VP7, VP4, VP6, and NSP4 genes to elucidate the evolutionary relationships in the community. All strains had a long RNA electropherotype, supported by VP6 gene analysis, clearly associated with subgroup II specificity. The phylogenetic analysis of VP7 gene sequences showed that they all clustered into lineage I, as reported for G1 strains in Japan, China, Vietnam, and Thailand. In addition, phylogenetic analysis of the VP4 gene showed that they belong to two distinct lineages, P[8]‐II and P[8]‐III. With respect to the NSP4 gene, all strains belonged to genotype B. An understanding of the ecology and molecular evolution of rotaviruses circulating in the country is very important for the development of vaccines and vaccination strategies. This study provides new information concerning the genetic variability of the rotavirus strain G1P[8] occurring most commonly as a vaccine candidate. J. Med. Virol. 82: 886–896, 2010. © 2010 Wiley‐Liss, Inc.     

Phylogenetic and computational structural analysis of VP7 gene of group a human rotavirus G1P[8] strains obtained in Sapporo, Japan from 1987 to 2000

Many studies indicate that G1P[8] genotypes are the most prevalent rotavirus strains worldwide. Although two vaccines have been licensed and their value proven in many countries, continuous surveillance for genetic evolution of circulating rotavirus strains before and after the introduction of the vaccines is desirable. G and P typing were carried out on all field strains isolated during 1987–2000 in Sapporo, Japan. Phylogenetic analysis for the VP7 gene of rotavirus G1P[8] strains was performed. Amino acid substitutions were mapped on the predicted three‐dimensional VP7 protein image. G1P[8] genotype predominated. One hundred thirteen strains with G1P[8] genotype were analyzed. Phylogenetic studies of the VP7 gene classified these strains into three lineages. The mean estimated substitution rate was 7.25 × 10^?4 nucleotide substitutions per site per year. One predominant lineage contained the mutant strains which had VP7 amino acid substitutions at residue 91 and 212 that is in the neutralization domains. They were estimated to locate in or near intersubunit boundary of VP7 trimer. It is suggested that the most prevalent G1P[8] lineage strains in Sapporo obtained some survival advantages by changing the neutralization domains of VP7. J. Med. Virol. 84:832–838, 2012. © 2012 Wiley Periodicals, Inc.     

Whole-genome sequence analysis of a Korean G11P[25] rotavirus strain identifies several porcine-human reassortant events

A rare rotavirus, RVA/Human-wt/KOR/CAU12-2/2012/G11P[25], was isolated from a 16-year-old female with fever and diarrhea during the 2012 rotavirus surveillance in South Korea using a cell culture system, and its full genome sequence was determined and analyzed. Strain CAU12-2 exhibited a G11-P[25]-I12-R1-C1-M1-A1-N1-T1-E1-H1 genotype constellation. Phylogenetic analysis of this strain revealed that it is a human-porcine reassortant of two distant relatives of the G11 strains circulating in the world. The VP7 and VP4 genes are most closely related to those of human G11P[25] viruses (Dhaka6, KTM368, and N-38 strains) identified in South Asia, whereas the VP1 gene originated from a porcine G11P[7] virus (YM strain) that was identified in South America. The VP6 gene was found to belong to the new genotype I12. This study indicates that the G11-P[25]-I12 genotype was introduced into the South Korean population by interspecies transmissions of human and animal rotaviruses, followed by multiple reassortment events.     

A hospital based study on inter- and intragenotypic diversity of human rotavirus A VP4 and VP7 gene segments,Germany

BackgroundEfforts to reduce the impact of group A rotaviruses on human morbidity and mortality rely on oral immunisation with live attenuated or recombinant vaccines. A major challenge in immunisation is the vast inter- and intragenotypic diversity accomplished by circulating rotaviruses.ObjectivesTo monitor rotavirus inter- and intragenotypic diversity in hospitalised children.Study designFrom January 2008 to December 2009 stool samples from 1994 paediatric in-patients suffering from diarrhoea were screened for rotavirus. Rotavirus G- and P-genotypes were determined by nucleotide sequencing and phylogenetic analysis was performed.ResultsRotavirus A was detected in stool samples of 341 children, comprising G1P[8], G2P[4], G3P[8], G4P[8], G9P[8], as well as uncommon G12P[6] genotypes and mixed infections. Predominant strains shifted from G1P[8] and G9P[8] genotypes in the first season to G3P[8] and G4P[8] genotypes in the second season. The highest intragenotypic diversity was detected in G1 strains and consisted of co-circulating G1-Ic, G1-Id, G1-Ie and G1-II rotaviruses. The G2 analysis revealed different intragenotypic lineages: G2-IIa, G2-IIb and G2-IIc. Interestingly, the circulating G4-Ib rotaviruses were characterised by insertions of 3 or 6 additional coding nucleotides within variable region 4 of VP7. Whereas different G9-III VP7 gene segments were detected G3-Ia sequences were highly homologous. In the VP4 analysis P[8]-III gene segment predominated over P[4]-Vb, P[8]-I, P[8]-IV and P[6]-I.ConclusionsA remarkable rotavirus heterogeneity was detected in the limited local setting and time span. Continued monitoring and nucleotide sequencing is necessary to document possible effects of rising immunisation levels on intragenotypic rotavirus diversity.     

Predominance of G9P[8] rotavirus strains throughout France, 2014–2017

ObjectivesGroup A rotavirus is a major cause of acute gastroenteritis in young children worldwide. A prospective surveillance network has been set up in France to investigate rotavirus infections and to detect the emergence of potentially epidemic strains.MethodsFrom 2014 to 2017, rotavirus-positive stool samples were collected from 2394 children under 5 years old attending the paediatric emergency units of 13 large hospitals. Rotaviruses were genotyped by RT-PCR with regard to their outer capsid proteins VP4 and VP7.ResultsGenotyping of 2421 rotaviruses showed that after a marked increase in G9P[8] (32.1%) during the 2014–2015 season, G9P[8] became the predominant genotype during the 2015–2016 and 2016–2017 seasons with detection rates of 64.1% and 77.3%, respectively, whereas G1P[8] were detected at low rates of 16.8% and 6.6%, respectively. Phylogenetic analysis of the partial rotavirus VP7 and VP4 coding genes revealed that all of these G9P [8] strains belonged to the lineage III and the P [8]-3 lineage, respectively, and shared the same genetic background (G9-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1) as did most of previously detected G9P[8] strains and particularly the emerging G9P[8] strains from the 2004–2005 season in France.ConclusionsG9P[8] rotaviruses have become the predominant circulating genotype for the first time since their emergence a decade ago. In the absence of rotavirus immunization programmes in France, our data give an insight into the natural fluctuation of rotavirus genotypes in a non-vaccinated population and provide a base line for a better interpretation of data in European countries with routine rotavirus vaccination.     

Characterisation of rotavirus G9 strains isolated in the UK between 1995 and 1998

G9P[6] and G9P[8] rotavirus strains were identified during 1995/96 through the molecular epidemiological surveillance of rotavirus strains circulating in the UK between 1995 and 1998. An increase in the incidence and spread of sporadic infections with rotavirus genotype G9P[8] across the UK was detected in the two following seasons. Partial sequencing of the VP7 gene showed that all the UK strains shared a high degree of homology and were related very closely to G9 strains from the US and from symptomatic infections in India (> or =96% homology). The UK strains were related more distantly to the apathogenic Indian strain 116E (85-87.8% homology). Phylogenetic analysis revealed clustering of the UK strains into 3 different lineages (I to III) and into two sub-lineages within lineage I. There were correlations between VP7 sequence clustering, the P type and the geographical origin of the G9 strains. Partial sequencing of the VP4 gene showed high degree of homology (>98%) among all the P[6] strains, and the sequences obtained from the P[8] strains clustered into 2 of the 3 global lineages described for P[8] strains associated with other G types. These data suggest that G9 strains may be a recent importation into the UK, and that G9P[8] strains may have emerged through reassortment in humans between G9P[6] strains introduced recently and the more prevalent cocirculating G1, G3 and G4 strains that normally carry VP4 genes of P[8] type.     

Detection of human rotavirus G9P[8] strains circulating in Argentina: phylogenetic analysis of VP7 and NSP4 genes

During the surveillance of rotavirus strains that were circulating in Argentinean children from 2000 to 2004, seven rotaviruses were detected bearing the genotype combination G9P[8]. The molecular characterization of the VP7 and NSP4 genes and the RNA migration patterns support the hypothesis that rotaviruses G9 could have been reintroduced into Argentina as a novel G9P[8] strain, rather than represent VP7 gene reassortants from G9P[6] strains that had been circulating previously in this country.     

Genetic variation of G4P[6] rotaviruses: Evidence for novel strains circulating between the hospital and community

One hundred forty‐six fecal specimens collected between 2007 and 2008 from infants with acute gastroenteritis were screened for rotavirus by ELISA with VP6‐specific antibody. One hundred twenty‐three of the samples (84.2%) were confirmed to be positive for group A rotavirus (community‐acquired, n = 90 [73.2%] and nosocomial, n = 33 [26.8%]), and were typed subsequently using RT‐PCR and sequence analysis methods. Determination of G‐ and P‐type combinations showed that G4P[6] (78.9%) was the most common strain, followed by G3P[8] (7.3%), G1P[8] (6.5%), G2P[4] (0.8%), G2P[6] (0.8%), G1P[6] (0.8%), and G9P[8] (0.8%) strains. Of the 97 G4P[6] strains, 62 (63.8%) were responsible for community‐acquired cases and 35 (36.1%) were hospital‐acquired cases. Phylogenetic analysis of the VP7 gene from the G4P[6] strains revealed that both the community‐acquired and nosocomial strains were segregated to the human rotaviruses circulating world‐wide, including the prototype vaccinal strain, ST3, which constituted a novel sublineage in lineage 1. Owing to the recent emergence of G4P[6] rotaviruses within the hospital, as well as in the community, the findings from this study are important since they provide new information concerning the community and nosocomial spread of rotaviruses. J. Med. Virol. 82:700–706, 2010. © 2010 Wiley‐Liss, Inc.     

Genomic characterization of a cell-culture-adapted Korean human G9P[8] rotavirus, CAU05-202

The human rotavirus G9 strain is the fifth most common rotavirus worldwide. A human rotavirus G9P[8] strain CAU05-202 was isolated from a young child with diarrhea using a cell culture system, and its major gene sequences were determined. Phylogenetic analysis of the VP7 gene revealed that CAU05-202 clustered into genetic lineage III-d and was most closely related to G9 rotaviruses from Turkey (strain GUH13) and Sri Lanka (strain 05SLC056 and 05SLC057). VP4 and NSP4 gene analysis showed that CAU05-202 belongs to the P[8]-3 lineage and genotype B, respectively. In addition, CAU05-202 has a long RNA electropherotype, supported by VP6 gene analysis, which is clearly associated with subgroup II specificity. Analysis of the G9 rotavirus strain CAU05-202 provides information concerning the genetic relationships among global rotavirus G9 strains, suggesting that closely related G9 strains are persistent and widespread in Asian countries.     

Molecular characterization of group A human rotaviruses in Bangkok and Buriram,Thailand during 2004–2006 reveals the predominance of G1P[8], G9P[8] and a rare G3P[19] strain

The aim of this study has been to determine the incidence of diverse human rotavirus strains circulating in Thailand between October 2004 and April 2006 by means of molecular characterization. Pediatric patients aged between 2 months and 5 years diagnosed with acute diarrhea (n = 307) in Bangkok and Buriram, Thailand were tested for human rotavirus A (RV-A) by RT-PCR. A total of 130 specimens (42.3%) were found RV-A positive and 126 were characterized by direct sequencing of the capsid glycoproteins VP7 and VP4. BLAST/FASTA analysis and phylogenetic analysis revealed genotypes G1P[8] (85.7%), G2P[4] (2.4%), G2P[8] (0.8%), G3P[8] (1.6%), G9P[8] (8.7%), and the uncommon strain G3P[19] (0.8%). Varying sites of polymorphism over time imply dependence on geographical location along with seasonal variation of relative incidence and distribution of rotavirus types. Thus, continuous molecular monitoring of human rotavirus epidemiology is essential for adjusting vaccine development.     

Multiple‐gene characterization of rotavirus strains: Evidence of genetic linkage among the VP7‐, VP4‐, VP6‐, and NSP4‐encoding genes

A total of 162 rotavirus strains detected between 1996 and 2006 among individuals with diarrhea in Rio de Janeiro, Brazil, were analyzed by multiple‐gene genotyping. Characterization of strains was done by RT‐PCR assay for amplification and typing of the VP7‐, VP4‐, VP6‐, and NSP4‐encoding genes. Overall, 139 (85.8%) strains belonged to the common group A rotavirus combinations: 67 (41.4%) belonged to genotype G1‐P[8]‐I1‐E1; 18 (11.1%) were G2‐P[4]‐I2‐E2; 11 (6.8%) were G3‐P[8]‐I1‐E1; 12 (7.4%) were G4‐P[8]‐I1‐E1; and 31 (19.1%) were G9‐P[8]‐I1‐E1. Two samples presented mixed genotypes (G1 + G3‐P[8]‐I1‐E1 and G1 + G9‐P[9]‐I1‐E1) and rare combinations, such as G2‐P[6]‐I2‐E2 and G9‐P[6]‐I2‐E2, were detected in six (3.7%) strains. The results suggest a linkage among all four genes. Genotypes G1/G3/G4/G5/G9‐P[8] were correlated strongly to I1‐E1 genotypes and G2‐P[4]/P[6] were correlated to I2‐E2 genotypes. Unusual combinations of genes, such as G3‐P[9]‐I2‐E2, G9‐P[9]‐I1‐E2, and G3‐P[9]‐I3‐E3, were observed in 15 (9.3%) strains. The characterization of multiple genes allows a more complete analysis of the rotavirus isolates and provides evidence of natural reassortment of strains. J. Med. Virol. 82:1797–1802, 2010. © 2010 Wiley‐Liss, Inc.     

Serological and genomic characterization of human rotaviruses detected in China

A total of 1,385 stool specimens were collected from children with diarrhea at two hospitals in Wuhan, Hubei Province, China, in 1994 and 1995, and screened for rotavirus by polyacrylamide gel electrophoresis of viral RNA. Group A rotavirus was detected with high frequency; 56.5% (87/154) and 40.8% (502/1,231) of the specimens collected in 1994 and 1995, respectively, were positive for rotavirus. Assignment of G serotype and P type (VP4 genotype) of group A rotavirus by ELISA with monoclonal antibodies and/or PCR, respectively, showed that strains of G2-P[4] and G1-P[8] specificity were predominant in 1994 and in 1995, respectively. In contrast, a single strain was found to have a P[9] type specificity, and no G4 strain was detected. Unusual combinations of RNA pattern-subgroup-G serotype-P type, such as long pattern-subgroup I-G1-P[8], short pattern-subgroup II-G3-P[4] and short pattern-subgroup I-G1-P[4], were detected in four specimens. Nucleotide sequences of the VP8* and/or NSP5 genes from two Chinese P[8] strains 470 and 582 and one Chinese P[9] strain 512 as well as five Japanese P[9] strains (K8, AU1, M318, O264, and O265) were determined and compared with the published sequences of the corresponding gene. In the phylogenetic tree of VP8* sequences of P[9] strains, which formed two clusters each having strain K8 or AU-1 as the representative strain, the Chinese P[9] strain was found in the cluster represented by AU-1, although it was most distantly related to other strains. While NSP5 sequences of human strains with P[9] specificity were related to simian and bovine strains, that of Chinese P[8] strains was most closely related to those of porcine strains. A single group C rotavirus (No. 208) was detected. Nucleotide sequences of its VP4, VP6, VP7, and NSP4 genes were very similar to those of group C human rotaviruses detected worldwide. J. Med. Virol. 55:168–176, 1998. © 1998 Wiley-Liss, Inc.     

Rotavirus strains bearing the VP4P[14] genotype recovered from South African children with diarrhoea

Summary.  Human rotavirus VP4P[14] strains were previously recovered in South Africa [18]. The strains exhibited a long RNA pattern, VP6 subgroup II and VP7 serotype G1. Two of the VP8^* genes were cloned and sequenced and demonstrated a high nucleotide homology with the prototype P[14] strains (PA169 and HAL1166). Received January 15, 1998 Accepted October 22, 1998     

Characterization of human rotavirus genotype P[8]G5 from Brazil by probe-hybridization and sequence

Summary We report the molecular characterization of rotavirus genotype P[8]G5 strains found in fecal specimens collected in four different regions of Brazil, using digoxigenin (dig)-labeled oligonucleotide probes, sequence analysis, and RNA-RNA hybridization. The closest sequence relationships of the neutralization antigens of these strains were to the VP4 protein of P1A[8]G1 strain KU (93.3% identity in amino acids 11 to 282) and to the VP7 protein of G serotype 5 strain OSU (87.6% identity in amino acids 8 to 232). Based on VP7 sequence differences, we designed dig-probes that allowed us to discriminate porcine OSU-like strains from G5 strains isolated from Brazilian infants. The genetic relationships of two P[8]G5 isolates to other rotavirus genogroups were analyzed by RNA-RNA hybridization with [³²P]-GTP probes representative of serotypes P1A[8]G1 (Wa), P[8]G3 (AU17), and P9[7]G5 (OSU). The Brazilian P[8]G5 strains showed sequence homology with genes of Wa-like and OSU-like strains, suggesting that these two strains were naturally occurring reassortants between members of the Wa and porcine rotavirus genogroups. The identification of these strains in diverse geographic areas of Brazil underscores their stability and demonstrates the emergence of clinically important rotavirus diarrhea strains by reassortment.     

Brazilian P[8],G1, P[8],G5, P[8],G9, and P[4],G2 rotavirus strains: nucleotide sequence and phylogenetic analysis

Rotavirus epidemiological surveys with molecular analysis of strains are required for gastroenteritis control and prevention. Twenty-nine human rotavirus strains detected in Rio de Janeiro, Brazil, from 1986 to 2004 were characterized as P[8],G1, P[8],G5, P[8],G9, and P[4],G2 genotypes. The VP7 genes were sequenced and phylogenetic analysis was performed. Strains of genotype G1 revealed two distinct lineages, G1-3 and G1-4; strains of genotype G2 grouped in lineage G2-1; G5 strains clustered with other Brazilians G5 strains and G9 strains were closely related to each other in lineage G9-3, distinct from the original G9 strains detected in 1980s. The VP4 genes were analyzed and P[8] strains fell into two major genetic lineages, P[8]-2 and P[8]-3. Our findings document an intragenotype diversity represented by lineages and sublineages within rotavirus circulating in Rio de Janeiro from 1986 to 2004, before application of a vaccine (Rotarix) in Brazil. This report emphasizes the importance of continuing monitor genotypes to verify if uncommon strains or newly strains are emerging to be specifically addressed in future vaccine trials.     

Full genomic analysis of a human rotavirus G1P[8] strain isolated in South Korea

A rotavirus G1P[8] strain C1‐81 was isolated from a 5‐month‐old female infant admitted to hospital with fever and severe diarrhea in Incheon, South Korea. To investigate its full genomic relatedness and its group, the full genome of strain C1‐81 was determined. Based on a full genome classification system, C1‐81 was shown to possess the typical Wa‐like genotype constellation: G1‐P[8]‐I1‐R1‐C1‐M1‐A1‐N1‐T1‐E1‐H1. On the basis of sequence similarities, the strain was shown to be the closest related strain to contemporary human rotavirus strains with recent strains isolated in Asia. This C1‐81 strain showed the highest degree of nucleic acid similarity (98.8% and 97%) to G1 B4633‐03 and P[8] (Thai‐1604 and Dhaka8‐02), respectively. This is the first report that group A rotavirus was analyzed with G1P[8] in South Korea. The study of the complete genome of the virus will help understanding of the evolution of rotavirus. J. Med. Virol. 85:157–170, 2012. © 2012 Wiley Periodicals, Inc.