Genome analysis of two type 6 echovirus (E6) strains recovered from sewage specimens in Greece in 2006

Echovirus 6 (E6) is one of the main enteroviral serotypes that was isolated from cases of aseptic meningitis and encephalitis during the last years in Greece. Two E6 (LR51A5 and LR61G3) were isolated from the sewage treatment plant unit in Larissa, Greece, in May 2006, 1 year before their characterization from aseptic meningitis cases. The two isolates were initially found to be intra-serotypic recombinants in the genomic region VP1, a finding that initiated a full genome sequence analysis. In the present study, nucleotide, amino acid, and phylogenetic analyses for all genomic regions were conducted. For the detection of recombination events, Simplot and bootscan analyses were carried out. The continuous phylogenetic relationship in 2C–3D genomic region of strains LR51A5 and LR61G3 with E30 isolated in France in 2002–2005 indicated that the two strains were recombinants. SimPlot and Bootscan analyses confirmed that LR51A5 and LR61G3 carry an inter-serotypic recombination in the 2C genomic region. The present study provide evidence that recombination events occurred in the regions VP1 (intraserotypic) and non-capsid (interserotypic) during the evolution of LR51A5 and LR61G3, supporting the statement that the genomes of circulating enteroviruses are a mosaic of genomic regions of viral strains of the same or different serotypes. In conclusion, full genome sequence analysis of circulating enteroviral strains is a prerequisite to understand the complexity of enterovirus evolution.     

Molecular identification and full genome analysis of an echovirus 7 strain isolated from the environment in Greece

Two enteroviruses from river water and four from sewage treatment plant were isolated in Larissa, Greece, that all shared the same sequence. A full genome analysis was conducted in an attempt to reveal the evolutionary pathways of one of the isolated strains (LR11F7). VP1 nucleotide and phylogenetic analysis revealed that the isolated strain had 78% homology with the echovirus 7 prototype strain Wallace. Full genome analysis revealed that LR11F7 P1 region is related to echoviruses 7 and that P2 and P3 regions are originating from contemporary enteroviruses isolated in South Asia. Two recombination events were shown to be involved into the evolutionary history of LR11F7, the one event concerning 3A, 3B, and 2C, and the other concerning 3D genomic region, both with new types of HEV-B. The contribution of recombination to enterovirus evolution is substantial, giving rise to new genetic lineages with unknown properties.     

Molecular epidemiology of rotaviral infection in South Indian children with acute diarrhea from 1995-1996 to 1998-1999

The distribution of VP7 (G-) and VP4 (P-) genotypes among 126 rotavirus strains from South Indian children, < 5 years of age and with acute diarrhoea, presenting to a single hospital during the months to November and December, from 1995 to 1998, was studied. Multiplex hemi-nested G- and P-typing polymerase chain reactions determined 101 (80%) G types and 78 (61%) P types, respectively. In order of frequency, the commonest G types were G1, G4, G2, G9, G3, and G8, and P types were P1B[4], P1A[8], and P2A[6] and the most common G:P combinations were G1:P1A[8], G1:P1B[4], G2P1B[4] and G4:P1A[8]. G1, G2, and G4 types were seen in all years. The single G3 isolate was seen in 1998. The single G8 isolate and the 5 G9 isolates were seen in 1997, after a period of heavy rain. Sequence analysis showed that the G8 isolate was related most closely to the bovine strain A5, and the G9 strains were distinct from the nonpathogenic Indian isolate 116E and similar to G9s isolated in Mysore and the United Kingdom described previously.     

Diversity in Indian equine rotaviruses: identification of genotype G10,P6[1] and G1 strains and a new VP7 genotype (G16) strain in specimens from diarrheic foals in India

Rotaviruses causing severe diarrhea in foals in two organized farms in northern India, during the period from 2003 to 2005, were characterized by electropherotyping, serotyping, and sequence analysis of the genes encoding the outer capsid proteins. Of 137 specimens, 47 (34.31%) were positive for rotavirus and exhibited at least five different electropherotypes (E), E1 to E5. Strains belonging to different electropherotypes exhibited either a different serotype/genotype specificity or a lack of reactivity to typing monoclonal antibodies (MAbs) used in this study. Strains belonging to E1, E2, and E5 exhibited genotype G10,P6[1], G3, and G1 specificities and accounted for 19.0, 42.9, and 9.5% of the isolates, respectively. Though they possessed G10-type VP7, the E1 strains exhibited high reactivity with the G6-specific MAb, suggesting that the uncommon combination of the outer capsid proteins altered the specificity of the conformation-dependent antigenic epitopes on VP7. E3 and E4 strains accounted for 28.6% of the isolates and were untypeable. Sequence analysis of VP7 from E4 strains (Erv92 and Erv99) revealed that they represent a new VP7 genotype, G16. The detection of unexpected bovine rotavirus-derived G10,P6[1] reassortants, G1 serotype strains, and a new genotype (G16) strain in two distant farms reveals an interesting epidemiological situation and diversity of equine rotaviruses in India.     

Isolation and genetic characterization of two G3P5A[3] canine rotavirus strains in Italy

Two strains of canine rotavirus were isolated from pups with clinical signs of gastroenteritis. Both strains were identified by polymerase chain reaction (PCR) as G3P5A[3], although restriction endonuclease analysis of the PCR amplicons revealed a genetic difference between the two isolates in the VP7 gene. The isolation in Italy of canine rotaviruses displaying the same VP7 and VP4 specificities as in the USA and in Japan, suggests that the G3 and P5A[3] types are highly conserved among canine rotavirus strains.     

Laboratory investigation and phylogenetic analysis of enteroviruses involved in an aseptic meningitis outbreak in Greece during the summer of 2007

BackgroundAseptic meningitis is the most commonly observed CNS infection and is mainly attributed to Non-Polio Enteroviruses (EV).ObjectiveIdentification and genetic analysis of the EV involved in the recent aseptic meningitis outbreak which occurred in Greece, during the summer of 2007.Study designIn total, 213 CSF and faecal samples were examined for EV presence by culture, while enteroviral RNA detection was performed by nucleic acid sequence-based amplification assay (NASBA). EV strains were typed by seroneutralization, as well as nested RT-PCR followed by VP1-2A gene partial sequencing. Phylogenetic analysis was carried out for the identification of the genetic relatedness among the isolated EV strains.ResultsEV detection rate in CSF and faecal samples was 43.9% and 70.8%, respectively. EV serotyping and VP1 region analysis revealed the predominance of echovirus 4 (ECV4) serotype and the circulation of ECV6, 9, 14, 25, Coxsackie A6, A15, A24 and Coxsackie B1 serotypes. All ECV4 isolates presented a 98.7% similarity in nucleotide sequence, with a Spanish ECV4 strain, isolated during a meningitis outbreak in 2006.ConclusionsIt is the first time that ECV4 is associated with an aseptic meningitis outbreak in Greece, during which 9 different EV serotypes were co-circulating. All Greek ECV4 isolates were closely related to the Spanish ECV4 strain. Genetic analysis of the VP1 gene can significantly contribute to the revelation of the endemic EV strains circulation pattern and their phylogenetic relationship with enteroviruses involved in epidemics of distant geographical areas at different time periods.     

肠道病毒71型VP1及2A基因特征研究

目的 检测临床分离的肠道病毒71型(EV71)轻型、重型毒株VP1基因、2A基因的核苷酸序列,进行遗传进化途径分析.方法 将50份临床手足口病患者粪便标本处理后分离病毒,用EV71特异性引物进行RT-PCR扩增,获得EV71毒株,针对不同临床背景的标本,分别选取轻型、重型的毒株,用特异性引物分别对VP1基因及2A基因进行RT-PCR扩增,对其产物进行测序及遗传进化分析,并探讨它们之间的差别.结果 50份临床手足口病标本中有30份检测是EV71,其中轻型(手足口)13份,重型(手足口并发脑炎或心肌炎)17份.轻型和重型中各自选取5株对VP1基因和2A基因进行测序和遗传学分析,通过同源性比较和构建系统发生树发现,此10株EV71病毒和中国大陆已发表的5株EV71病毒(fuyangEU703814.1、xi_anHM003207.1、shandongEU753418.1、shenzhen-FJ607337.1、henanGU366191.1)全部属于C基因型,且核苷酸同源性较高,VP1基因和2A基因的同源性分别在94.7%～99.4%和93.6%～99.3%范围内.本次分离的10株EV71病毒与A、B基因型代表株比较,核苷酸同源性分别为81.0%～84.6%和78.4%～82.2%,差异较大.与已知的C1、C2、C3亚型代表株比较,核苷酸同源性在87.8%～90.2%,差异≥10%,与已知的C4亚型代表株比较,核苷酸同源性在96.8%～99.6%,因此认为可将这10株病毒划分为C4亚型.在系统发生树上,这10株病毒形成一个较独立的分支.结论 EV71 C4亚型病毒在中国大陆有较广泛的传播,且毒株之间VP1基因的遗传关系紧密;2A基因在轻型和重型病例毒株之间遗传差异不大.     

肠道病毒71型VP1及2A基因特征研究

目的 检测临床分离的肠道病毒71型(EV71)轻型、重型毒株VP1基因、2A基因的核苷酸序列,进行遗传进化途径分析.方法 将50份临床手足口病患者粪便标本处理后分离病毒,用EV71特异性引物进行RT-PCR扩增,获得EV71毒株,针对不同临床背景的标本,分别选取轻型、重型的毒株,用特异性引物分别对VP1基因及2A基因进行RT-PCR扩增,对其产物进行测序及遗传进化分析,并探讨它们之间的差别.结果 50份临床手足口病标本中有30份检测是EV71,其中轻型(手足口)13份,重型(手足口并发脑炎或心肌炎)17份.轻型和重型中各自选取5株对VP1基因和2A基因进行测序和遗传学分析,通过同源性比较和构建系统发生树发现,此10株EV71病毒和中国大陆已发表的5株EV71病毒(fuyangEU703814.1、xi_anHM003207.1、shandongEU753418.1、shenzhen-FJ607337.1、henanGU366191.1)全部属于C基因型,且核苷酸同源性较高,VP1基因和2A基因的同源性分别在94.7%～99.4%和93.6%～99.3%范围内.本次分离的10株EV71病毒与A、B基因型代表株比较,核苷酸同源性分别为81.0%～84.6%和78.4%～82.2%,差异较大.与已知的C1、C2、C3亚型代表株比较,核苷酸同源性在87.8%～90.2%,差异≥10%,与已知的C4亚型代表株比较,核苷酸同源性在96.8%～99.6%,因此认为可将这10株病毒划分为C4亚型.在系统发生树上,这10株病毒形成一个较独立的分支.结论 EV71 C4亚型病毒在中国大陆有较广泛的传播,且毒株之间VP1基因的遗传关系紧密;2A基因在轻型和重型病例毒株之间遗传差异不大.     

肠道病毒71型VP1及2A基因特征研究

目的 检测临床分离的肠道病毒71型(EV71)轻型、重型毒株VP1基因、2A基因的核苷酸序列,进行遗传进化途径分析.方法 将50份临床手足口病患者粪便标本处理后分离病毒,用EV71特异性引物进行RT-PCR扩增,获得EV71毒株,针对不同临床背景的标本,分别选取轻型、重型的毒株,用特异性引物分别对VP1基因及2A基因进行RT-PCR扩增,对其产物进行测序及遗传进化分析,并探讨它们之间的差别.结果 50份临床手足口病标本中有30份检测是EV71,其中轻型(手足口)13份,重型(手足口并发脑炎或心肌炎)17份.轻型和重型中各自选取5株对VP1基因和2A基因进行测序和遗传学分析,通过同源性比较和构建系统发生树发现,此10株EV71病毒和中国大陆已发表的5株EV71病毒(fuyangEU703814.1、xi_anHM003207.1、shandongEU753418.1、shenzhen-FJ607337.1、henanGU366191.1)全部属于C基因型,且核苷酸同源性较高,VP1基因和2A基因的同源性分别在94.7%～99.4%和93.6%～99.3%范围内.本次分离的10株EV71病毒与A、B基因型代表株比较,核苷酸同源性分别为81.0%～84.6%和78.4%～82.2%,差异较大.与已知的C1、C2、C3亚型代表株比较,核苷酸同源性在87.8%～90.2%,差异≥10%,与已知的C4亚型代表株比较,核苷酸同源性在96.8%～99.6%,因此认为可将这10株病毒划分为C4亚型.在系统发生树上,这10株病毒形成一个较独立的分支.结论 EV71 C4亚型病毒在中国大陆有较广泛的传播,且毒株之间VP1基因的遗传关系紧密;2A基因在轻型和重型病例毒株之间遗传差异不大.

Abstract：

Objective To detect VP1 and 2A genes of Enterovirus type 71 (EV71) isolated from clinical specimens of patients with light or heavy symptoms and analyze the homogeneity and phylogenetic tree. Methods Fifty clinical specimens of children with hand-foot-and-mouth disease ( HFMD) were dealed with, which were tested by RT-PCR assay with specific primer pairs for EV71. EV71 isolates from patients with light or heavy clinical symptoms were tested by RT-PCR assay with two specific primer pairs for VP1 and 2A genes of EV71 respectively. All of the PCR products were sequenced and compared with that of previously isolated EV71 isolates available from GenBank by homogeneity and phylogenetic tree analyses. Results The RT-PCR results indicated that 30 isolates were EV71, 13 of 30 isolates were from clinical specimens of patients with light symptoms of hand-foot and mouth, the other were from clinical specimens of patients with heavy symptoms of complications. VP1 genes and 2A genes of 10 EV71 isolated strains including 5 light strains and 5 heavy strains were sequenced and compared with that of previously isolated 5 EV71 Chinese isolates available from GenBank (fuyangEU703814.1, xi_anHM003207. 1, shandongEU753418.1, shenzhenFJ607337.1, henanGU366191. 1) by homogeneity and phylogenetic tree analyses. The homogeneity of VP1 and 2A genes of the 10 EV71 isolated strains and 5 previously isolated strains were between 94.7% -99.4% and 93.6% -99.3% respectively, with the representative isolates of A and B genotypes was between 81.0%-84. 6% and 78. 4%-82. 2% respectively. The data suggested that all of the 10 Chinese isolates belong to EV71 genotype C. There were only 87.8% -90.2% homology among these 10 strains and the representative strains of C1, C2, C3 sub-genotypes of EV71 but 96. 8% -99.6% homology among these 10 strains and the representative strains of C4 sub-genotypes of EV71, this suggested that these 10 Chinese isolates composed the C4 sub-genotype, of the C genotype, that formed a single branch in the phylogenetic tree. Conclusion EV71 of sub-genotype C4 distributed in Mainland China, and VP1 genes have close genetic relationship between isolated strains. There is no obvious difference in 2A genes between clinical specimens of patients with light or heavy symptoms by homogeneity and phylogenetic tree analyses.     

A novel genomic constellation (G10P[3]) of group A rotavirus detected from buffalo calves in northern India

Group A bovine rotaviruses cause gastroenteritis and calf mortality leading to significant economic losses to dairy farmers in India. Due to segmented nature of the RNA genome and wide host range, vast genetic and antigenic diversity exists among different isolates of rotavirus. Molecular characterization of locally prevalent group A rotavirus strains in buffalo population in north India was undertaken. Out of a total of 455 faecal samples, 21 samples (4.61%) were positive for bovine rota virus (BRV) as determined by PAGE and ELISA, whereas of these only 15 isolates yielded specific products for VP4 and VP7 genes by RT-PCR. Genotyping by nested PCR typed G6, G10 and P[11] genotypes but VP4 genes of 11 isolates remained untyped. The phylogenetic and evolutionary analysis of nucleotide and predicted amino acid sequences of the cloned products of VP4 and VP7 genes confirmed typing results obtained by nested PCR for G6, G10 and P[11] and classified the untyped isolates as P[3] genotypes. In this study, it was observed that G6P[11] (26.66%) and G10P[3] (73.34%) group A rotaviruses are circulating in buffalo herds of organized farms in north India. Unusual reassortants G10P[3] of group A rotaviruses isolated from buffalo calves show novel genomic constellations indicative of interspecies reassortment.     

Predominance of G3B and G14 equine group A rotaviruses of a single VP4 serotype in Japan

A total of 65 equine group A rotaviruses (GAR) isolated from diarrheal foals at 48 farms in Hokkaido, Japan, between 1996 (29 isolates) and 1997 (36 isolates) were characterized for their VP7 and VP4 serotypes by PCR, nucleotide sequencing, and virus neutralization (VN) tests. By PCR VP7 typing, all isolates were classified as G3 or G 14, and the predominant serotype in each year was G3 (86%) in 1996 and G14 (53%) in 1997. VN tests with these 20 isolates randomly selected confirmed the specificity of PCR on the bases of complete agreement of the results in these methods (9 G3 and 11 G14), and revealed that all 9 G3 isolates were subtype G3B. There were five differing amino acid residues in three VP7 antigenic regions between subtypes G3A and G3B. Antiserum to a baculovirus recombinant that expressed P[12] VP4 neutralized all isolates and P[12] reference strains. These results suggest that genotype P[12] GAR belong to a single VP4 serotype, and that one VP4 and two VP7 serotypes (G3B and G14) of GAR were predominant in the equine population in Japan.     

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.     

Correlation between rotavirus A genotypes detected in hospitalized children and sewage samples in 2006, Córdoba,Argentina

Routine rotavirus A (RV‐A) surveillance is based on clinical cases, so only symptomatic infections are reported. The objective of this study was to determine whether the RV‐A genotypes and cold seasonal pattern described in patients with diarrhea is reflected by sewage surveillance, which could be representative of the RV‐A genotypes circulating in the population. The genotype distribution of RV‐A in effluent samples from a local sewage treatment plant was compared to those from local clinical cases. A total of 52 sewage samples and 70 stool specimens from children with acute non‐bacterial diarrhea were collected from January to December 2006. The effluent specimens were concentrated and RNA extracts from concentrated sewage and clinical samples were genotyped for the rotavirus VP7 gene. The proportional distribution of the RV‐A G‐genotypes in sewage and clinical samples during the cold season was similar: G1 accounted for 26.6% of the typed sewage isolates and 28.8% of the clinical infections; G3 type accounted for 21.9% and 25.8%; G2 type 15.6% and 10.6%; G4 type 17.2% and 21.2%; G8 type 1.6% and 0%; and the G9 type 17.2% and 13.6%, respectively. A similar picture of RV‐A genotype detection was obtained in sewage samples collected during the cold and warm seasons. The results indicate that there is a correlation between genotypes of RV‐A isolates from human diarrheic patients and of those from sewage samples. In addition, sewage monitoring highlighted the uniform all‐year RV‐A circulation, which was in contrast to the peak incidence of RV‐A infection in the community. J. Med. Virol. 82: 1277–1281, 2010. © 2010 Wiley‐Liss, Inc.     

A rotavirus strain isolated from pig-tailed macaque (Macaca nemestrina) with diarrhea bears a P6[1]:G8 specificity

A distinct rotavirus strain (PTRV) was isolated in cell cultures from a stool sample obtained from a diarrheic 3-year-old female pig-tailed macaque (Macaca nemestrina) that was born at the breeding colony of the University of Washington in Seattle. Unlike other known simian rotavirus strains including vervet monkey rotavirus SA11 which bears P5B[2]:G3 or P6[1]:G3 specificity, rhesus monkey rotavirus MMU18006 with P5B[3]:G3 specificity, pig-tailed macaque rotavirus YK-1 with P[3]:G3 specificity and rhesus monkey rotavirus TUCH with P[24]:G3 specificity, the cell-culture-grown PTRV strain was shown to bear P6[1]:G8 specificity as determined by VP4 (P)- and VP7 (G)-specific neutralization assays as well as gene sequence analyses. The virus in the original diarrhea stool was also shown to bear genotypes P[1] and G8. In addition, the PTRV strain exhibited a "long" electropherotype, subgroup I specificity and NSP4 genotype A specificity. The PTRV probe formed (i) 8-9 hybrid bands with genomic RNAs of various bovine rotavirus strains and (ii) only 2-3 hybrid bands with simian rotavirus RNAs as demonstrated by RNA-RNA hybridization, suggesting a possible bovine origin of the virus. Serologic analysis of serum samples obtained from selected pig-tailed macaques in the colony suggested that a rotavirus bearing P[1]:G8 specificity was endemic among macaques for at least 8 years (1987-1994). This is the first report describing an isolation of a simian rotavirus bearing a non-G3 VP7 and possibly a P6[1] specificities. Because of its unique simian serotype, this virus may prove to be valuable in challenge studies in a non-human primate model in studies of rotavirus immunity.     

Full genomic analysis of a porcine–bovine reassortant G4P[6] rotavirus strain R479 isolated from an infant in China

During the 2004 surveillance of rotaviruses in Wuhan, China, a G4P[6] rotavirus strain R479 was isolated from a stool specimen collected from a 2‐year‐old child with diarrhea. The strain R479 had an uncommon subgroup specificity I + II, and analysis of the VP6 gene suggested that it was related to porcine rotaviruses. In the present study, full‐length nucleotide sequences of all the RNA segments of R479 were determined and analyzed phylogenetically to identify the origin of individual RNA segments. According to the rotavirus genotyping system based on 11 RNA segments, the genotype of R479 was expressed as G4‐P[6]‐I5‐R1‐C1‐M1‐A1‐N1‐T7‐E1‐H1. This genotype includes the porcine‐like VP6 genotype (I5) and bovine‐like NSP3 genotype (T7). Phylogenetic analysis revealed that R479 genes encoding VP1, VP2, VP3, VP6, VP7, VP8*, NSP1, NSP4, and NSP5 were more closely related to those of porcine rotaviruses than human or other animal rotaviruses. In contrast, it was remarkable that the NSP3 gene of R479 was genetically closely related to only a bovine rotavirus strain UK. The NSP2 gene of R479 was also unique and clustered with only the G5P[8] human strain IAL28 and G3P[24] simian strain TUCH. These results suggested that R479 may be a reassortant virus having the NSP3 gene from a bovine rotavirus in the genetic background of a porcine rotavirus, with an NSP2 gene related to the porcine‐human reassortant strain IAL28. To our knowledge, R479 is the first porcine–bovine reassortant rotavirus isolated from a human. J. Med. Virol. 82:1094–1102, 2010. © 2010 Wiley‐Liss, Inc.     

Characterization of human symptomatic rotavirus isolates MP409 and MP480 having ‘long’ RNA electropherotype and subgroup I specificity, highly related to the P6[1],G8 type bovine rotavirus A5, from Mysore, India

Summary.  In an epidemiological study of symptomatic human rotaviruses in Mysore, India during 1993 and 1994, isolates MP409 and MP480 were isolated from two children suffering from severe, acute dehydrating diarrhea. Both isolates exhibited ‘long’ RNA pattern and subgroup I specificity suggesting the likelihood of their animal origin. Both isolates did not react with monoclonal antibodies (MAbs) specific for serotypes G1 to G6 as well as G10. To determine the genetic origin of these isolates, complete nucleotide sequences of genes encoding the outer capsid proteins VP4 and VP7, nonstructural proteins NSP1 and NSP3 and viral enterotoxin protein NSP4 from MP409 and partial sequences of genes from MP480 were determined. Comparison of the 5′ and 3′ terminal sequences of 250 nucleotides revealed complete identity of the gene sequences in both strains suggesting that MP409 and MP480 are two different isolates of a single strain. Comparison of the nucleotide and deduced amino acid sequences of VP4, VP7, NSP1 and NSP3 of MP409 with published sequences of strains belonging to different serotypes revealed that both outer capsid proteins VP4 and VP7 and NSP1 are highly related to the respective proteins from the P6[1], G8 type bovine rotavirus A5 isolated from a calf with diarrhoea in Thailand and that the NSP3 is highly homologous to that of bovine rotaviruses. The NSP4 protein showed greatest sequence identity with NSP4s belonging to the KUN genetic group to which NSP4s from human G2 type strains and bovine rotaviruses belong. MP409 and MP480 likely signify interspecies transmission of P6[1], G8 type strains from cattle to humans and represent the first P6[1] type rotaviruses isolated in humans. These and our previous studies on the asymptomatic neonatal strain I321 are of evolutionary and epidemiological significance in the context of close association of majority of the Indian population with cattle. Received September 29, 1999 Accepted February 4     

Genetic and antigenic characterization of a serotype P[6]G9 human rotavirus strain isolated in the United States

During an epidemiologic survey of rotavirus infections established to monitor the prevalent G serotypes circulating in the United States, human P[6]G9, subgroup I rotavirus strains causing symptomatic infections were identified as the fourth most common serotype. In this report we describe the molecular and antigenic characterization of one of these P[6]G9 isolates (US1205). Neutralization and sequencing studies have demonstrated that both outer capsid proteins, VP7 and VP4, of US1205 are closely related to but genetically and antigenically distinguishable from those of standard G9 strains (e.g., F45, WI61) and standard P2A[6] strains (e. g., ST3, M37). Thus the complete antigenic type of US1205 is P2A[6]G9, subgroup I. Sequence analysis of the VP6 and NSP4 genes of US1205 indicates that strain US1205 possessed VP6 subgroup I and NSP4A genotype specificities. Finally, Northern hybridization studies suggest that the P[6]G9 strains are closely related to members of the DS-1 genogroup except for their P[6] VP4 gene, which has been commonly identified in strains of both major human genogroups, and their G9 VP7 gene, which may have been derived by reassortment with a Wa genogroup strain. Examination of historic collections and prospective surveillance of strains will be needed to determine whether this strain has been present for some time or if it is emerging to compete with the other common serotypes of rotavirus.     

Comparative amino acid sequence analysis of the major outer capsid protein (VP7) of porcine rotaviruses with G3 and G5 serotype specificities isolated in Venezuela and Argentina

Summary Seven porcine group A rotavirus strains isolated in Venezuela were shown to be antigenically related to serotype G3 (five strains) or to serotype G5 (two strains), whereas two strains isolated in Argentina were classified as serotype G5. The serological classification of eight of these strains was confirmed by sequence analysis of the gene encoding the VP7 glycoprotein. A high degree of homology was observed among strains belonging to the same G serotype, although some variations in the serotype-specific regions were detected among different strains. Comparison with the published VP7 amino acid sequences of serotype G3 indicated that most porcine rotavirus strains are more closely related to each other and to human rotavirus strains than to rotavirus strains isolated from other species. Amino acid sequence comparison among serotype G5 porcine strains revealed that Venezuelan porcine isolates were more closely related to the American strain OSU, while the Argentinian strains had a higher similarity to the Australian strain TRF-41. This report confirms the worldwide distribution of these G serotypes among the porcine population.     

2008至2009年北京地区分离的肠道病毒71型全基因组序列分析

目的了解2008至2009年从北京地区手足口病（HFMD）患儿分离到的肠道病毒71型（EV71）全基因组序列特点（未包括多聚腺苷尾）,以探讨基因序列的改变是否与病毒的致病性有关。方法选取首都儿科研究所病毒研究室2008年分离到的5株EV71毒株和2009年分离到的4株EV71毒株,其中4株来源于重症HFMD患儿（伴高热、持续抽搐及意识丧失等中枢神经系统症状）,5株来源于轻症HFMD患儿。设计覆盖病毒全基因组的10对特异性引物,对9株EV71毒株进行RT-PCR扩增、全基因组序列测定和分析。结果 9株EV71毒株的全基因组长度为7406bp或7405bp,部分毒株在5′UTR存在1处1个碱基的缺失。9株EV71毒株的全基因组核苷酸和氨基酸同源性分别为96.3%～99.4%和98.2%～99.6%,在VP1区核苷酸和氨基酸同源性分别为96.9%～99.9%和98.3%～100.0%。重症HFMD来源的4株毒株中有3株在VP2蛋白第144位及3D聚合酶（3Dpol）第140和263位同时出现相同的氨基酸变异（T144S、R140K和I263V）,并且在5′UTR区第208和254位同时出现相同的碱基变异（G208A和A254G）。9株EV71毒株的全基因组与C4亚型毒株具有最高的核苷酸同源性,在VP1区为94.3%～95.5%;在3D及3′UTR区与CV-A16/G10的同源性（84.3%～85.0%和89.0%～91.5%）高于与EV71-B型、A型及C型（C1～3、C5）的同源性。VP1和3D基因的遗传进化分析显示,9株EV71毒株与C4亚型毒株属同一分支。结论 VP2蛋白第144位氨基酸突变（T→S）、3Dpol第140和263位氨基酸突变（R→K和I→V）及5′UTR区第254位碱基突变（A→G）可能与EV71感染后引起的不同临床症状有关。根据VP1核苷酸序列,2008至2009年北京地区流行的EV71属于C4亚型;非结构蛋白基因在EV71进化中可能有一定的作用。