北京地区2007-2008年G9型A组人轮状病毒VP7和VP4基因分析

目的 了解北京地区2007-2008年检测到的G9型A组人轮状病毒外壳蛋白VP7和VP4的基因特征.方法 选取经过轮状病毒核酸杂交方法检测为G9型轮状病毒的12份儿童腹泻患儿的粪便标本,应用针对VP7全长基因的特异引物对进行RT-PCR扩增,对所获得的VP7全长基因进行克隆和测序,将所获得的序列与GenBank中的G9型原型病毒株和近期流行株的VP7基因进行序列和种系进化分析;经巢式PCR对G9型的VP4进行P基因分型.结果 12株G9型轮状病毒经VP7基因的序列比较分析得到确认.P基因分型结果显示北京地区近年来存在G9P[8]和G9P[6]型两种组合的轮状病毒感染.序列和种系进化分析发现北京G9型株VP7基因与世界范围内近期流行的G9型株一样都属于进化分支Ⅲ,彼此间的核苷酸和氨基酸同源性较高,而与国内最早报道的G9型T203进化关系较远,且北京G9P[8]和G9P[6]型株分别与国内近期报道的新疆G9P[8]和G9P[6]型株及相应的武汉G9型株VP7基因,在氨基酸位点上存在一些共同的氨基酸残基取代.结论 北京地区近年存在G9P[8]和G9P[6]两种不同基因组合的G9型轮状病毒感染,需要进一步加强对G9型轮状病毒的分子流行病学监测.     

Whole genome sequencing reveals genetic heterogeneity of G3P[8] rotaviruses circulating in Italy

After a sporadic detection in 1990s, G3P[8] rotaviruses emerged as a predominant genotype during recent years in many areas worldwide, including parts of Italy. The present study describes the molecular epidemiology and evolution of G3P[8] rotaviruses detected in Italian children with gastroenteritis during two survey periods (2004–2005 and 2008–2013). Whole genome of selected G3P[8] strains was determined and antigenic differences between these strains and rotavirus vaccine strains were analyzed. Among 819 (271 in 2004–2005 and 548 in 2008–2013) rotaviruses genotyped during the survey periods, the number of G3P[8] rotavirus markedly varied over the years (0/83 in 2004, 30/188 in 2005 and 0/96 in 2008, 6/88 in 2009, 4/97 in 2010, 0/83 in 2011, 9/82 in 2012, 56/102 cases in 2013). The genotypes of the 11 gene segments of 15 selected strains were assigned to G3-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1; thus all strains belonged to the Wa genogroup. Phylogenetic analysis of the Italian G3P[8] strains showed a peculiar picture of segregation with a 2012 lineage for VP1-VP3, NSP1, NSP2, NSP4 and NSP5 genes and a 2013 lineage for VP6, NSP1 and NSP3 genes, with a 1.3–20.2% nucleotide difference from the oldest Italian G3P[8] strains. The genetic variability of the Italian G3P[8] observed in comparison with sequences of rotaviruses available in GenBank suggested a process of selection acting on a global scale, rather than the emergence of local strains, as several lineages were already circulating globally. Compared with the vaccine strains, the Italian G3P[8] rotaviruses segregated in different lineages (5–5.3% and 7.2–11.4% nucleotide differences in the VP7 and VP4, respectively) with some mismatches in the putative neutralizing epitopes of VP7 and VP4 antigens. The accumulation of point mutations and amino acid differences between vaccine strains and currently circulating rotaviruses might generate, over the years, vaccine-resistant variants.     

Molecular characterization of two rare human G8P[14] rotavirus strains,detected in Italy in 2012

Since 2007, the Italian Rotavirus Surveillance Program (RotaNet-Italy) has monitored the diversity and distribution of genotypes identified in children hospitalized with rotavirus acute gastroenteritis.We report the genomic characterization of two rare human G8P[14] rotavirus strains, identified in two children hospitalized with acute gastroenteritis in the southern Italian region of Apulia during rotavirus strain surveillance in 2012.Both strains showed a G8-P[14]-I2-R2-C2-M2-A11-N2-T6-E2-H3 genomic constellation (DS-1-like genomic background). Phylogenetic analysis of each genome segment revealed a mixed configuration of genes of animal and zoonotic human origin, indicating that genetic reassortment events generated these unusual human strains. Eight out of 11 genes (VP1, VP2, VP3, VP6, VP7, NSP3, NSP4 and NSP5) of the Italian G8P[14] strains exhibited close identity with a Spanish sheep strain, whereas the remaining genes (VP4, NSP1 and NSP2) were more closely related to human strains. The amino acid sequences of the antigenic regions of outer capsid proteins VP4 and VP7 were compared with vaccine and field strains, showing high conservation between the amino acid sequences of Apulia G8P[14] strains and human and animal strains bearing G8 and/or P[14] proteins, and revealing many substitutions with respect to the RotaTeq™ and Rotarix™ vaccine strains. Conversely, the amino acid analysis of the four antigenic sites of VP6 revealed a high degree of conservation between the two Apulia strains and the human and animal strains analyzed.These results reinforce the potential role of interspecies transmission and reassortment in generating novel rotavirus strains that might not be fully contrasted by current vaccines.     

Molecular characterization of group A rotaviruses detected in children with gastroenteritis in Ireland in 2006-2009

Community and hospital-acquired cases of human rotavirus are responsible for millions of gastroenteritis cases in children worldwide, chiefly in developing countries, and vaccines are now available. During surveillance activity for human rotavirus infections in Ireland, between 2006 and 2009, a total of 420 rotavirus strains were collected and analysed. Upon either PCR genotyping and sequence analysis, a variety of VP7 (G1-G4 and G9) and VP4 (P[4], P[6], P[8] and P[9]) genotypes were detected. Strains G1P[8] were found to be predominant throughout the period 2006-2008, with slight fluctuations seen in the very limited samples available in 2008-2009. Upon either PCR genotyping and sequence analysis of selected strains, the G1, G3 and G9 viruses were found to contain E1 (Wa-like) NSP4 and I1 VP6 genotypes, while the analysed G2 strains possessed E2 NSP4 and I2 VP6 genotypes, a genetic make-up which is highly conserved in the major human rotavirus genogroups Wa- and Kun-like, respectively. Upon sequence analysis of the most common VP4 genotype, P[8], at least two distinct lineages were identified, both unrelated to P[8] Irish rotaviruses circulating in previous years, and more closely related to recent European humans rotaviruses. Moreover, sequence analysis of the VP7 of G1 rotaviruses revealed the onset of a G1 variant, previously unseen in the Irish population.     

Reassortant group A rotavirus from straw-colored fruit bat (Eidolon helvum)

Bats are known reservoirs of viral zoonoses. We report genetic characterization of a bat rotavirus (Bat/KE4852/07) detected in the feces of a straw-colored fruit bat (Eidolon helvum). Six bat rotavirus genes (viral protein [VP] 2, VP6, VP7, nonstructural protein [NSP] 2, NSP3, and NSP5) shared ancestry with other mammalian rotaviruses but were distantly related. The VP4 gene was nearly identical to that of human P[6] rotavirus strains, and the NSP4 gene was closely related to those of previously described mammalian rotaviruses, including human strains. Analysis of partial sequence of the VP1 gene indicated that it was distinct from cognate genes of other rotaviruses. No sequences were obtained for the VP3 and NSP1 genes of the bat rotavirus. This rotavirus was designated G25-P[6]-I15-R8(provisional)-C8-Mx-Ax-N8-T11-E2-H10. Results suggest that several reassortment events have occurred between human, animal, and bat rotaviruses. Several additional rotavirus strains were detected in bats.     

Molecular characterization of rotavirus strains detected during a clinical trial of a human rotavirus vaccine in Blantyre, Malawi

The human, G1P[8] rotavirus vaccine (Rotarix?) significantly reduced severe rotavirus gastroenteritis episodes in a clinical trial in South Africa and Malawi, but vaccine efficacy was lower in Malawi (49.5%) than reported in South Africa (76.9%) and elsewhere. The aim of this study was to examine the molecular relationships of circulating wild-type rotaviruses detected during the clinical trial in Malawi to RIX4414 (the strain contained in Rotarix?) and to common human rotavirus strains. Of 88 rotavirus-positive, diarrhoeal stool specimens, 43 rotaviruses exhibited identifiable RNA migration patterns when examined by polyacrylamide gel electrophoresis. The genes encoding VP7, VP4, VP6 and NSP4 of 5 representative strains possessing genotypes G12P[6], G1P[8], G9P[8], and G8P[4] were sequenced. While their VP7 (G) and VP4 (P) genotype designations were confirmed, the VP6 (I) and NSP4 (E) genotypes were either I1E1 or I2E2, indicating that they were of human rotavirus origin. RNA-RNA hybridization using 21 culture-adapted strains showed that Malawian rotaviruses had a genomic RNA constellation common to either the Wa-like or the DS-1 like human rotaviruses. Overall, the Malawi strains appear similar in their genetic make-up to rotaviruses described in countries where vaccine efficacy is greater, suggesting that the lower efficacy in Malawi is unlikely to be explained by the diversity of circulating strains.     

Whole genome sequencing and phylogenetic analysis of a zoonotic human G8P[14] rotavirus strain

The full-length genome of a rare human G8P[14] rotavirus strain, BP1062/04, identified during a surveillance study in Hungary was determined and analyzed. This strain showed a G8-P[14]-I2-R2-C2-M2-A11-N2-T6-E2-H3 genomic constellation. Phylogenetic analysis of each genome segment revealed common origins with selected animal and zoonotic human strains. The closest relatedness was seen with suspect zoonotic Hungarian G6P[14] strains in the NSP1 and NSP3 gene phylogeny, with ovine strains in the VP1, VP2, NSP4 gene phylogeny, and with bovine strains in the NSP5 gene phylogeny. The outer capsid VP7 and VP4 genes could not be derived from cognate genes of any known human or animal G8P[14] strains. The remaining genes, NSP2, VP3 and VP6, gave no definite clues to the host origin, although each was clearly different from true human strains. Altogether, our findings suggest that strain BP1062/04 represents an example of a direct zoonotic transmission event.     

Whole genome analysis of multiple rotavirus strains from a single stool specimen using sequence-independent amplification and 454? pyrosequencing reveals evidence of intergenotype genome segment recombination

Infection of a single host cell with two or more different rotavirus strains creates conditions favourable for evolutionary mechanisms like reassortment and recombination that can generate novel strains. Despite numerous reports describing mixed rotavirus infections, whole genome characterisation of rotavirus strains in a mixed infection case has not been reported. Double-stranded RNA, exhibiting a long electropherotype pattern only, was extracted from a single human stool specimen (RVA/Human-wt/ZAF/2371WC/2008/G9P[8]). Both short and long electropherotype profiles were however detected in the sequence-independent amplified cDNA derived from the dsRNA, suggesting infection with more than one rotavirus strain. 454? pyrosequencing of the amplified cDNA revealed co-infection of at least four strains. Both genotype 1 (Wa-like) and genotype 2 (DS-1-like) were assigned to the consensus sequences obtained from the nine genome segments encoding NSP1-NSP5, VP1-VP3 and VP6. Genotypes assigned to the genome segments encoding VP4 were P[4] (DS-1-like), P[6] (ST3-like) and P[8] (Wa-like) genotypes. Since four distinct genotypes [G2 (DS-1-like), G8, G9 (Wa-like) and G12] were assigned to the four consensus nucleotide sequences obtained for genome segment 9 (VP7), it was concluded that at least four distinct rotaviruses were present in the stool. Intergenotype genome recombination events were observed in genome segments encoding NSP2, NSP4 and VP6. The close similarities of some of the genome segments encoding NSP2, VP6 and VP7 to artiodactyl rotaviruses suggest that some of the infecting strains shared common ancestry with animal strains, or that interspecies transmission occurred previously. The sequence-independent genome amplification technology coupled with 454? pyrosequencing used in this study enabled the characterisation of the whole genomes of multiple rotavirus strains in a single stool specimen that was previously assigned single genotypes, i.e. G9P[8], by sequence-dependent RT-PCR.     

Detection of human G10 rotavirus strains with similarity to bovine and bovine-like equine strains from untypable samples

G10 rotaviruses, which are usually found in cattle, have also been reported in neonatal infections in recent years. During the rotavirus surveillances of children less than 4years of age between 2003 and 2006 in Kolkata, eastern India, 60 out of 1153 samples could not be typed. All 60 samples gave usual electropherotype pattern in polyacrylamide gel. Thirty-one out of these 60 G and P untypable rotavirus strains were successfully characterized during the study. Among 31 samples, G9P[4] (n=8), G12P[8] (n=8), G1P[8] (n=6), G10P[4] (n=6), and G2P[4] (n=3) genotypes were identified. In this study we report genetic analysis of the six G10 strains, which revealed close relations with Turkish (E29TR) bovine strains, as well as with bovine-like-equine strain (Erv2) from India. SimPlot of the VP7 gene segment suggested possible recombination event between the bovine and the bovine-like-equine rotaviruses in these human rotavirus infections.     

Reassortment of Human Rotavirus Gene Segments into G11 Rotavirus Strains

G11 rotaviruses are believed to be of porcine origin. However, a limited number of G11 rotaviruses have been recently isolated from humans in combination with P[25], P[8], P[6], and P[4]. To investigate the evolutionary relationships of these strains, we analyzed the complete genomes of 2 human G11P[25] strains, 2 human G11P[8] strains, and 3 porcine reference strains. Most of the 11 gene segments of these 7 strains belonged to genotype 1 (Wa-like). However, phylogenetic clustering patterns suggested that an unknown G11P[25] strain with a new I12 VP6 genotype was transmitted to the human population, in which it acquired human genotype 1 gene segments through reassortment, resulting in a human G11P[8] rotavirus strain with an entire human Wa-genogroup backbone. This Wa-like backbone is believed to have caused the worldwide spread of human G9 and G12 rotaviruses. G11 human rotavirus strains should be monitored because they may also become major human pathogens.     

Genetic diversity of species A rotaviruses detected in clinical and environmental samples,including porcine-like rotaviruses from hospitalized children in the Philippines

Rotaviruses are the major cause of severe acute diarrhea in infants and young children. Rotaviruses exhibit zoonosis and thereby infect both humans and animals. Viruses detected in urban rivers possibly reflect the presence of circulating viruses in the catchment. The present study investigates the genetic diversity of species A rotaviruses detected from river water and stool of hospitalized children with acute diarrhea in Tacloban City, the Philippines. Species A rotaviruses were detected by real-time RT-PCR and their genotypes were identified by multiplex PCR and sequencing of partial regions of VP7 and VP4. Rotaviruses were detected in 85.7% (30/35) of the river water samples and 62.7% (151/241) of the clinical samples. Genotypes of VP7 in the river water samples were G1, G2, G3, G4, G5, and G9, and those of VP4 were P[3], P[4], P[6], P[8], and P[13]. Genotypes of viruses from the clinical samples were G2P[4], G1P[8], G3P[8], G4P[6], G5P[6], and G9P[8]. Among those, G2P[4] in clinical samples (77.9%, 81/104) and P[4] of VP4 in river water samples (67.5%, 56/83)) were the most frequently detected rotavirus genotypes. However, G5 was the more frequently detected than G2 in the river water samples (42% vs. 13%) which may be originated from porcine rotavirus. Sequence analyses of eleven gene segments revealed one G5P[6] and two G4P[6] rotaviruses in the clinical samples, wherein, several gene segments were closely related to porcine rotaviruses. The constellation of these rotavirus genes suggests the emergence of reassortment between human and porcine rotavirus due to interspecies transmission.Although two commercial rotavirus vaccines are available now, these vaccines are designed to confer immunity against the major human rotaviruses. Constant monitoring of viral variety in populated areas where humans and domestic animals live in close proximity provides vital information related to the diversity of rotaviruses in a human population.     

Genotypic linkages of VP4, VP6, VP7, NSP4, NSP5 genes of rotaviruses circulating among children with acute gastroenteritis in Thailand

Rotavirus is the main cause of acute viral gastroenteritis in infants and young children worldwide. Surveillance of group A rotavirus has been conducted in Chiang Mai, Thailand since 1987 up to 2004 and those studies revealed that group A rotavirus was responsible for about 20-61% of diarrheal diseases in hospitalized cases. In this study, we reported the continuing surveillance of group A rotavirus in 2005 and found that group A rotavirus was detected in 43 out of 147 (29.3%) stool samples. Five different G and P genotype combinations were detected, G1P[8] (27 strains), G2P[4] (12 strains), G9P[8] (2 strains), G3P[8] (1 strain), and G3P[10] (1 strain). In addition, analysis of their genotypic linkages of G (VP7), P (VP4), I (VP6), E (NSP4), and H (NSP5) genotypes demonstrated that the rotaviruses circulating in Chiang Mai, Thailand carried 3 unique linkage patterns. The G1P[8], G3P[8], and G9P[8] strains carried their VP6, NSP4, NSP5 genotypes of I1, E1, H1, respectively. The G2P[4] strains were linked with I2, E2, H2 genotypes, while an uncommon G3P[10] genotype carried unique genotypes of I8, E3 and H6. These findings provide the overall picture of genotypic linkage data of rotavirus strains circulating in Chiang Mai, Thailand.     

Epidemiology and phylogenetic analysis of VP7 and VP4 genes of rotaviruses circulating in Rawalpindi,Pakistan during 2010

Human group A rotaviruses (RVAs) possess a large genetic diversity and new RVA strains and G/P genotype combinations are been identified frequently. Only a few studies reporting the distribution and co-circulation of RVA G and P genotypes are available for Pakistan. This hospital based study showed a RVA prevalence rate of 23.8%, which is similar to RVA detection rates estimated in other Eastern Mediterranean countries. During 2010, the following RVA strains were found to co-circulate: G1P[8] and G2P[4] (both 24.3%), G1P[6] (12.1%), G9P[8] (10.8%), G9P[6] (5.4%), G12P[6] (6.7%), G6P[1] (2.7%) and mixed infections (6.7%). Sequence analyses of selected G1, G2, G9 and G12 RVA strains revealed a close evolutionary relationship with typical human RVA strains. Sequence identities among the Pakistani VP7 RVA genes encoding G1, G2, G9 and G12 ranged between 91.5–98.7%, 99.6–98.9%, 97.7–99.5% and 99.2–99.9%, respectively. Analysis of the VP4 genes revealed co-prevalence of distinct lineages of the P[8] genotype. P[6] and P[4] showed a close relationship with typical human RVA strains detected in several Asian countries. The two G6P[1] RVA strains were closely related to typical bovine RVA strains, suggesting one or multiple interspecies transmission events. Our data provide important baseline data on the burden of RVA disease and genotype distribution in Rawalpindi, Pakistan, which is important with respect to vaccine introduction in national immunization programs.     

Intra-genotypic diversity of archival G4P[8] human rotaviruses from Washington, DC

Group A human rotaviruses (RVs) remain the most frequently detected viral agents associated with acute gastroenteritis in infants and young children. Despite their medical importance, relatively few complete genome sequences have been determined for commonly circulating G/P-type strains (i.e., G1P[8], G2P[4], G3P[8], G4P[8], and G9P[8]). In the current study, we sequenced the genomes of 11 G4P[8] isolates from stool specimens that were collected in Washington, DC during the years of 1974–1991. We found that the VP7–VP4–VP6–VP1–VP2–VP3–NSP1–NSP2–NSP3–NSP4–NSP5/6-encoding genes of all 11 G4P[8] RVs have the genotypes of G4-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1. By constructing phylogenetic trees for each gene, extensive intra-genotypic diversity was revealed among the G4P[8] RVs, and new sub-genotype gene alleles were identified. Several of these alleles are nearly identical to those of G3P[8] isolates previously sequenced from this same Washington, DC collection, strongly suggesting that the RVs underwent gene reassortment. On the other hand, we observed that some G4P[8] RVs exhibit completely different allele-based genome constellations, despite being collected during the same epidemic season; there was no evidence of gene reassortment between these strains. This observation extends our previous findings and supports the notion that stable, genetically-distinct clades of human RVs with the same G/P-type can co-circulate in a community. Interestingly, the sub-genotype gene alleles found in some of the DC RVs share a close evolutionary relationship with genes of more contemporary human strains. Thus, archival human RVs sequenced in this study might represent evolutionary precursors to modern-day strains.     

A decade of G3P[8] and G9P[8] rotaviruses in Brazil: Epidemiology and evolutionary analyses

This study aims to estimate the frequency of group A rotaviruses (RVA) infection with genotypes G3P[8] and G9P[8] in children that suffered from diarrheal disease (DD) between 2001 and 2011 in different Brazilian regions. In addition, the genetic diversity of G3P[8] and G9P[8] RVA strains recovered from vaccinated and non-vaccinated children was assessed. Laboratory-based RVA surveillance included 15,115 cases of DD, and RVA was detected by enzyme immune-assay and/or polyacrylamide gel electrophoresis in 3357 (22%) samples. RVA was genotyped by the semi-nested RT-PCR and among RVA-positive samples, 100 (2.9%) were G3 (63 G3P[8], 32 G3P not typed [NT], and 5 G3P[6]) and 378 (16.2%) were G9 (318 G9P[8], 59 G9P[NT], and 1 G9P[6]). From the G3 and G9 positive samples, 16 and 12, respectively, were obtained from children aged 4–48 months vaccinated with the monovalent vaccine (Rotarix®, RV1). Phylogenetic analyses of the VP7 and VP8¹ encoding genes were performed for 26 G3P[8] and 48 G9P[8] strains. VP8¹ phylogenetic analysis revealed that all strains analyzed belonged to P[8] lineage III, whereas RV1 belongs to P[8]-I lineage. VP7 analysis revealed that all G3 and G9 strains belonged to G3-lineage III and G9-lineage III. The comparison of the VP7 and VP8¹ antigenic epitopes regions of Brazilian strains with RV1 strain revealed several amino acid changes. However, no particular differences among Brazilian strains detected before and after vaccine introduction were observed, or among strains detected from vaccinated and non-vaccinated children. Complete genome characterization of four G3P[8] and seven G9P[8] strains revealed a typical conserved human Wa-like genomic constellation. Changes in the genetic diversity of G3P[8] and G9P[8] RVA detected from 2001 to 2011 in Brazil seemed not be related to RV1 introduction in Brazil.     

Epidemiological features and genetic characterization of virus strains in rotavirus associated gastroenteritis in children of Odisha in Eastern India

We have studied the clinical characteristics, severity and seasonality of rotavirus infection and prevalent genotypes in 652 non-rota vaccinated children in Odisha in eastern India. P genotypes were analysed for their association with host blood group antigens. P type of the virus is determined by the VP8* gene, and specific recognition of A - type of Histo - blood group antigen by P[14]VP8* has been reported. VP4, VP7 and VP6 genes of commonly identified G1P[8] strain were compared with genes of the same strain isolated from other parts of India, elsewhere and strains used for Rotarix and Rotateq vaccines.In 54.75% of children with gastroenteritis, rota virus was found. 9.65% of children had moderate, 78.07% severe, and 12.28% very severe disease as assessed using the Vesikari scoring system. The incidence of infection was highest during winter months. There was no association between any blood group and specific P genotypes. G1P[8] was the commonest cause of gastroenteritis, followed by G1P[11], G3P[8], G9P[8], G2P[4], G2P[6], G9P[4], G9P[11] and G1P[6]. Predominant G genotypes identified were G1 (72.9%), G9 (10.81%), G2 (8.10%) and G3 (8.10%). Sequence analysis of the VP7 gene, placed the G1P[8] strain in lineage 1 and of VP6 gene placed nine G1P[8] strains in subgroup II and one in subgroup I. The VP7 gene segment of two Odisha G1P[8] strains were found to cluster relatively close to the VP7 sequences of Rotarix vaccine. Antigenic differences were found with vaccine strains. Ten G1P[8] strains sequenced for the VP4 gene had 91–93% nucleotide and 92–96% amino acid identity with Rotateq vaccine P[8]). Rotarix vaccine VP4 had 89–91% nucleotide and 90–92% amino acid identity. Our findings indicate genetic variability of rotavirus strains circulating in the region and are significant, given the introduction of rota vaccination in the State.     

Surveillance and molecular characterization of rotavirus strains circulating in Manipur,North-Eastern India: Increasing prevalence of emerging G12 strains

To determine the frequency and genotypes of rotavirus strains, samples were collected from children hospitalized with acute diarrhea at the Regional Institute of Medical Sciences, Manipur. The globally common genotypes G1P[8] and G2P[4] constituted 58% of the total positive strains, while 3% and 8% strains were emerging genotypes, G9P[6] and G12P[6]. This is the first report of genotype G12 in Manipur. The G12 strains clustered with lineage III strains and had >98% identity with corresponding rotaviruses from Bangladesh, Thailand and the USA. Other uncommon G–P combinations including G4P[4], G4P[6], G10P[6] and G9P[19], along with a few strains that could not be typed were also found. The VP7 genes of G4 and G10 strains clustered with porcine and bovine strains, indicating possible zoonotic transmission. High frequency (36–62%) of rotavirus infection and predominance of G1P[8] and G2P[4] among children with acute diarrhea emphasized the need for implementation of currently available vaccines to reduce the burden of rotavirus induced diarrhea in India.     

Genomic characterization of uncommon human G3P[6] rotavirus strains causing diarrhea in children in Italy in 2009

Group A rotaviruses (RVA) are the leading cause of acute gastroenteritis in young children, causing up to 450,000 deaths worldwide, mostly in developing countries. Most of RVA human infections in developed countries are related to five major G/P combinations: G1P[8], G2P[4], G3P[8], G4P[8] and G9P[8]. During the surveillance activity of RotaNet-Italy, three uncommon G3P[6] RVA strains, designated as RVA/Human-wt/ITA/NA01/2009/G3P[6], RVA/Human-wt/ITA/NA06/2009/G3P[6], and RVA/Human-wt/ITA/NA19/2009/G3P[6], were identified in the stools of children with diarrhea hospitalized in Southern Italy in 2009. Samples NA01, NA06 and NA19 were characterized as genotype G3P[6]. To investigate the three strains further, partial sequencing of the eleven genomic segments was performed. RVA strains NA01, NA06 and NA19 were found to share the rare genotype constellation: G3-P[6]-I2-R2-C2-M2-A2-N2-T2-E2-H2, which had not been reported previously in continental Italy. The phylogenetic analysis of the eleven genomic segments showed no evidence of zoonosis or inter-species reassortment at the origin of the Italian G3P[6] strains, indicating that they possessed DS-1-like genomic constellations similar to those detected previously in human cases in Africa and Europe. The analysis of the hypervariable regions of VP7 and VP4 (VP8*) revealed high amino acid identity between the Italian G3P[6] RVA strains involved in this study.     

Epidemiology and genetic diversity of group A rotavirus in pediatric patients with acute gastroenteritis in Thailand, 2018–2019

Group A rotaviruses (RVAs) are the major viruses that cause acute gastroenteritis in young children worldwide. The objective of this study was to investigate the prevalence and genotype diversity of RVAs circulating in children with acute gastroenteritis in Thailand in 2018–2019. A total of 1170 stool specimens were obtained from children admitted to hospitals with diarrhea and screened for RVAs by nested RT-PCR. The RVA genotypes were determined by multiplex-PCR or nucleotide sequencing and phylogenetic analysis. Out of 1170 stool specimens, 209 (17.9%) were positive for RVAs. The RVA G9P[8] genotype (24.4%) was the most dominant genotype, followed by G3P[8] (22.9%), G8P[8] (22.0%), G1P[8] (16.7%), G2P[4] (6.7%), G1P[6] (2.3%), G1P[4] (1.0%), G3P[4] (1.0%), G9P[4] (1.0%), mixed-infections of G1P[4] + G1P[8] (1.0%), and GXP[8] (0.5%). Moreover, an uncommon RVA G3P[10] genotype (0.5%), bearing bat-like VP7 and VP4 genes, was detected. This study reveals the prevalence and genetic diversity of RVA genotypes in children with acute gastroenteritis in Thailand. The knowledge obtained from this study is helpful for understanding the epidemiology of rotavirus in Thailand. The emergence of uncommon RVA strain G3P[10] provides an evidence for interspecies transmission of human and animal rotaviruses.     

Genomic analysis of human rotavirus strains G6P[14] and G11P[25] isolated from Kolkata in 2009 reveals interspecies transmission and complex reassortment events

In a community based case–control study in Kolkata, India, in 2009, two human rotaviruses with uncommon genotypes G6P[14] and G11P[25] were identified, having bovine and porcine characteristics respectively. Strain N-1/2009 with G6P[14] and strain N-38/2009 with G11P[25] genotypes, were isolated from a 13 months aged boy who was asymptomatic and a 10 months old girl with severe diarrhea respectively. The remaining 9 gene segments of these two strains were analyzed to find the exact origin of these unusual rotaviruses, and the origin of these two strains from bovine/porcine rotaviruses was apparent. This study identifies zoonotic transmission and single and multiple reassortment events as mechanisms driving the diversity of human rotaviruses. This study indicates interspecies transmission between human and animal rotaviruses causes single or multiple reassortment and thus contribute to the genetic diversity of rotavirus.