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Objective@#To study the molecular epidemiology and genetic variation of coxsackievirus B5 (CV-B5) in certain areas in China.@*Methods@#MEGA 6.0 software was used to analyze the complete VP1 region of CV-B5 isolated strains from certain areas of China by retrieving the GenBank nucleotide database. Besides, the phylogenetic tree was constructed, the homology of nucleotide and amino acids were calculated and the rate of evolution was estimated.@*Results@#A total of 189 Chinese CV-B5 isolated strains were included in this study. Most of Chinese CV-B5 isolated strains belonged to genotype C, accounted for 90.5%. Compared with the genotype A, the homology of nucleotide sequences and amino acid sequences of complete VP1 region of 189 Chinese isolated strains were 79.8%-82.8% and 92.6%-97.9%, respectively; moreover, the nucleotide and the amino acid homology of 189 Chinese CV-B5 isolated strains among themselves ranged from 80.3% to 100.0% and ranged from 91.5% to 100.0%, respectively. The estimated rate of evolution of the CV-B5 was 4×10-3 substitutions/site/year.@*Conclusions@#The majority of CV-B5 isolated strains belonged to genotype C, and subgenotype C1 and C2 were co-circulating together in certain areas of China.
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Objective@#To illuminate the gene characteristics and clinical characterization of Coxsackievirus B5 (CV-B5) strains isolated from patients with sevre hand, foot and mouth disease (HFMD) in Qingdao city.@*Methods@#A total of 1 844 patients of HFMD were consecutively admitted to Qingdao Women and Children's Hospital from 2013 to 2014. Information of the study population described above was collected retrospectively. The samples were collected from at least 1 site (throat swab, cerebrospinal fluid), which viral nucleic acid extracted and the entire VP1 gene sequences of CV-B5 isolates were amplified and sequenced, then the homology and phylogeny analysis were conducted by MEGA7.0. The prototype Faulkner strain and other VP1 amino acid sequences were derived from the GenBank database.@*Results@#A total of 8 CV-B5 positive cases were obtained, including 4 males and 4 females; 6 severe hospitalized cases and 2 outpatients. The age of 6 hospitalized patients ranged from 3 to 48 months, with a median of 26 months. For the six inpatients, fever, convulsions vomiting, diarrhea and rash were the main clinical manifestation, and all combined with viral encephalitis. Compared with the prototype strain Faulkner, in the VP1 region,the nucleotide and the amino acid homologies was 77.3%-78.8% and 95.5%-97.0% respectively. Five out of the six severe cases with substitution of serine (S) to asparagine (N) at amino acid site 95 in the VP1 region. The sequences of 8 CV-B5 strains were classified into genogroup D.@*Conclusion@#Hand, foot and mouth disease associated with CV-B5 virus infection can result in nervous system involvement and the main complication was viral encephalitis. The CV-B5 strains associated with severe hand, foot and mouth disease had high nucleotide homology and present a certain regional aggregation.
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Objective To investigate the serotypes of human enterovirus B ( HEV-B) species cau-sing hand, foot and mouth disease ( HFMD) and to analyze the genetic characteristics of VP1 region in cox-sackievirus B2 ( CVB2 ) and coxsackievirus B5 ( CVB5 ) strains circulating in Anyang area during 2011 to 2015. Methods Real-time RT-PCR and semi-nested RT-PCR were performed to identify coxsackievirus A16 (CVA16), enterovirus 71 (EV71) and other serotypes of enterovirus in order to obtain the complete etiologic composition of HFMD. The numbers of HEV-B serotypes and the percentages of specimens positive for every serotype in all enterovirus-positive specimens were calculated. As CVB2 and CVB5 were the pre-dominant serotypes of HEV-B species, five pairs of primers targeting the VP1 regions of CVB2 and CVB5 were designed to obtain the complete nucleotide sequences of CVB2 and CVB5 VP1 regions. The phylogenet-ic trees were constructed based on the VP1 sequences obtained in this study and those submitted to GenBank by using MEGA7. 0 and BioEdit7. 2. The selection pressures on VP1 regions of CVB2 and CVB5 strains cir-culating in China in recent years were evaluated with the online program of DataMonkey. Results A total of 57 specimens that belonged to 14 serotypes of HEV-B species were detected in Anyang area from 2011 to 2015. The 14 serotypes of HEV-B species accounted for 56% of all serotypes of enterovirus and the speci-mens positive for HEV-B species accounted for 3. 06% of all enterovirus-positive specimens. The HFMD ca-ses caused by most of the HEV-B serotypes were sporadic cases. Small outbreaks of HFMD could also be caused by some serotypes of HEV-B such as CVB2 and CVB5. The complete sequences of VP1 region were obtained from 8 CVB2 strains and 9 CVB5 strains. The phylogenetic trees based on the VP1 sequences dem-onstrated that the CVB2 strains were classified into four genotypes ( A-D) . The mean evolutionary distances between different genotypes ranged from 0. 191 to 0. 208 and the similarities in nucleotide sequences ranged from 79. 7% to 85. 8%. The CVB5 strains were classified into 6 genotypes (A-F). The mean evolutionary distances and the similarities in nucleotide sequences between different genotypes of CVB5 strains ranged from 0. 170 to 0. 285 and 76. 0% to 86. 8%, respectively. Strains of different genotypes varied significantly in the residues on positons 157 and 263 in the VP1 region of CVB2 strains and on positions 75, 90 and 95 in the VP1 region of CVB5 strains. All of the CVB2 strains isolated in Anyang area belonged to D genotype and located intensively in one lineage. The CVB5 strains circulated in Anyang area belonged to F genotype and located in two lineages. The selection pressures on CVB2 strains of D genotype and CVB5 strains of F geno-type circulating in China in recent years were 0. 037 and 0. 036, respectively. Six positively selected amino acid sites were found in the VP1 region of CVB5 strains, but no positively selected amino acid site was found in the VP1 region of CVB2 strains. Conclusion HEV-B species was an essential component of the etiologic spectrum of HFMD in Anyang area during 2011 to 2015, of which CVB5 and CVB2 were the predominant se-rotypes. The VP1 region of CVB5 was more complex and active than that of CVB2 over the course of evolution.
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TO know the causative agent of asptic meningitis. we performed and cerebrospinal fluid study on 24 children who had been admitted to the department of Pediatrics.. Asam Medical Center form Jume. 1991 to July 1991. In the 10 cases of them. CSF virus culture was done Special Reference Laboratory, Japan The most of the patients were young infants, and 15 cases of them were under 3 months of age. The male to female ratio was 1:1.4 We observed the main symptoms as fever 100%. irritability 67%, vomiting 17%. poor feeding 13%, seizure 8%. In the 4 cases among the 10 cases with virus culture, Coxsackievirus B5 was cultured. We concluded that the causative agent of this epidemic aseptic meningitis in 1991 was Coxsakievirus B5.