Enterovirus 71 （EV71） is a common cause of Hand, foot, and mouth disease （HFMD） and may also cause severe neurological diseases, such as encephalitis and poliomyelitis-like paralysis. To examine the genetic divers...Enterovirus 71 （EV71） is a common cause of Hand, foot, and mouth disease （HFMD） and may also cause severe neurological diseases, such as encephalitis and poliomyelitis-like paralysis. To examine the genetic diversity of EV71, we determined and analyzed the complete VP1 sequences （891 nueleotides） from nine EV71 strains isolated in Fuyang, China. We found that nine EV71 strains isolated were over 98% homologous at the nucleotide level and 93%-100% homologous tO members of the C4 subgenogroup. At the amino acid level, these Fuyang strains were 99% -100% homologous to one another, 97%-100% homologous to members of the C4 subgenogroup, and the histidine（H） at amino acid position 22 was conserved among the Fuyang strains. The results indicate that Fuyang isolates belong to genotype C4, and an H at position 22 appears to be a marker for the Fuyang strains.展开更多
Human enterovirus 71 (EV71) is one of the major etiological agents of the hand-foot-and-mouth disease (HFMD) that often causes severe neurological complications. Recently,its outbreaks mainly take place in the torrid ...Human enterovirus 71 (EV71) is one of the major etiological agents of the hand-foot-and-mouth disease (HFMD) that often causes severe neurological complications. Recently,its outbreaks mainly take place in the torrid zone of the Asia-Pacific region. To study the evolution and genetic variability,we collected 532 EV71 strains with almost complete or complete VP1 sequences (891 nt) isolated worldwide from 1970 to 2004. The pairwise homologies and genetic distances were analyzed. Most strains belong to previously identified genotype B and C. However,a unique strain R13223-IND-01 appears not to fall into current three genotypes (A,B and C),and probably represents a new genotype D. Some orphan strains were observed in the genotypes B and C,and their significance in the EV71 evolution was discussed. Moreover,there is a significant co-variance of 6 discrete positions on VP1 (amino acid 43,58,164,184,240 and 249). This high co-variability is tightly related with the subgenotypes.展开更多
Infectious bursal disease(IBD)is caused by infectious bursal disease virus(IBDV),which has a genome consisting of two segments of double-stranded linear RNA.IBDVs have been traditionally divided into four phenotypes b...Infectious bursal disease(IBD)is caused by infectious bursal disease virus(IBDV),which has a genome consisting of two segments of double-stranded linear RNA.IBDVs have been traditionally divided into four phenotypes based on their pathogenicity and antigenicity,including classic,variant,very virulent,and attenuated IBDV.With the emergences of divergent molecular characteristics of novel strains produced by continuous mutations and recombination,it is increasingly difficult to define new IBDV strains using the traditional descriptive classification method.The most common classification scheme for IBDV with segmented genome is based solely on segment A,while the significance of segment B has been largely neglected.In this study,an improved scheme for IBDV genotype classification based on the molecular characteristics of both VP2(a viral capsid protein encoded by segment A)and VP1(an RNA-dependent RNA polymerase protein encoded by segment B)was proposed for the first time.In this scheme,IBDV was classified into nine genogroups of A and five genogroups of B,respectively;the genogroup A2 was further divided into four lineages.The commonly used phenotypic classifications of classic,variant,very virulent,and attenuated IBDVs correspond to the A1 B1,A2 B1,A3 B2,and A8 B1 genotypes of the proposed classification scheme.The novel variant IBDVs including the strains identified in this study were classified as belonging to genotype A2 d B1.The flexibility and versatility of this improved classification scheme will allow the unambiguous identification of existing and emerging IBDV strains,which will greatly facilitate molecular epidemiology studies of IBDV.展开更多
基金Scientific Research Fund of Institute of Pathogen Biology(2008IPB108)
文摘Enterovirus 71 （EV71） is a common cause of Hand, foot, and mouth disease （HFMD） and may also cause severe neurological diseases, such as encephalitis and poliomyelitis-like paralysis. To examine the genetic diversity of EV71, we determined and analyzed the complete VP1 sequences （891 nueleotides） from nine EV71 strains isolated in Fuyang, China. We found that nine EV71 strains isolated were over 98% homologous at the nucleotide level and 93%-100% homologous tO members of the C4 subgenogroup. At the amino acid level, these Fuyang strains were 99% -100% homologous to one another, 97%-100% homologous to members of the C4 subgenogroup, and the histidine（H） at amino acid position 22 was conserved among the Fuyang strains. The results indicate that Fuyang isolates belong to genotype C4, and an H at position 22 appears to be a marker for the Fuyang strains.
基金Supported by the National Natural Science Foundation of China (Grant No. 30221003)
文摘Human enterovirus 71 (EV71) is one of the major etiological agents of the hand-foot-and-mouth disease (HFMD) that often causes severe neurological complications. Recently,its outbreaks mainly take place in the torrid zone of the Asia-Pacific region. To study the evolution and genetic variability,we collected 532 EV71 strains with almost complete or complete VP1 sequences (891 nt) isolated worldwide from 1970 to 2004. The pairwise homologies and genetic distances were analyzed. Most strains belong to previously identified genotype B and C. However,a unique strain R13223-IND-01 appears not to fall into current three genotypes (A,B and C),and probably represents a new genotype D. Some orphan strains were observed in the genotypes B and C,and their significance in the EV71 evolution was discussed. Moreover,there is a significant co-variance of 6 discrete positions on VP1 (amino acid 43,58,164,184,240 and 249). This high co-variability is tightly related with the subgenotypes.
基金the Natural Science Foundation of Heilongjiang Province,China(ZD2020C006 and TD2019C003)the National Key Research and Development Program of China(2016YFE0203200)+2 种基金the Heilongjiang Province Foundation for the National Key Research and Development Program of China(GX18B011)the Major Project of National Natural Science Foundation of China(31430087)the earmarked fund for China Agriculture Research System(CARS-41-G15)。
文摘Infectious bursal disease(IBD)is caused by infectious bursal disease virus(IBDV),which has a genome consisting of two segments of double-stranded linear RNA.IBDVs have been traditionally divided into four phenotypes based on their pathogenicity and antigenicity,including classic,variant,very virulent,and attenuated IBDV.With the emergences of divergent molecular characteristics of novel strains produced by continuous mutations and recombination,it is increasingly difficult to define new IBDV strains using the traditional descriptive classification method.The most common classification scheme for IBDV with segmented genome is based solely on segment A,while the significance of segment B has been largely neglected.In this study,an improved scheme for IBDV genotype classification based on the molecular characteristics of both VP2(a viral capsid protein encoded by segment A)and VP1(an RNA-dependent RNA polymerase protein encoded by segment B)was proposed for the first time.In this scheme,IBDV was classified into nine genogroups of A and five genogroups of B,respectively;the genogroup A2 was further divided into four lineages.The commonly used phenotypic classifications of classic,variant,very virulent,and attenuated IBDVs correspond to the A1 B1,A2 B1,A3 B2,and A8 B1 genotypes of the proposed classification scheme.The novel variant IBDVs including the strains identified in this study were classified as belonging to genotype A2 d B1.The flexibility and versatility of this improved classification scheme will allow the unambiguous identification of existing and emerging IBDV strains,which will greatly facilitate molecular epidemiology studies of IBDV.
