ABSTRACT
To analyze the genetic characteristics of echovirus 6 (E6) isolated from meningitis and encephalitis cases in Shandong Province, China, we collected cerebrospinal fluid samples from meningitis and encephalitis cases in Shandong Province from 2007 to 2012 for virus isolation. Viral RNAs were extracted from positive isolates, and complete VP1 coding regions were amplified by RT-PCR and sequenced. Homology comparison and phylogenetic analysis were performed. Six isolates were identified as E6 by microneutralization assay and molecular typing. The homology analysis showed that the six isolates had 78. 6%-99. 8% nucleotide and 95. 5%-100. 0% amino acid identities with each other, as well as 76. 9%-78. 4% nucleotide and 92. 3%-95. 1% amino acid identities with the prototype strain (D' Amori). The phylogenetic analysis based on the integrated VP1 sequences indicated that all Shandong E6 isolates could be separated into four clusters, designated as A, B, C, and D. The six E6 isolates belonged to clusters A, B, and D. Our study reveals high genetic differences between Shandong E6 isolates and suggests different transmission lineages of E6 co-circulated in Shandong Province.
Subject(s)
Child , Child, Preschool , Female , Humans , Infant , Male , Amino Acid Sequence , China , Epidemiology , Echovirus 6, Human , Classification , Genetics , Encephalitis , Epidemiology , Virology , Genetic Variation , Meningitis , Epidemiology , Virology , Molecular Sequence Data , Phylogeny , Sequence Alignment , Viral Proteins , Chemistry , GeneticsABSTRACT
We wished to analyze the genetic characterization of echovirus 11 (Echo11) from samples of environmental sewage in Shandong Province (China). The VP1 coding region was typed as the strains were amplified. Phylogenetic analyses on the VP1 sequences from these isolates, strains isolated from AFP cases in the period 1994-2010 and others published in GenBank were conducted. From 2011 to 2012, 94 Echo11 strains were isolated from samples of environmental sewage in Jinan and Linyi City in Shandong Province. Numbers of Echo11 were seasonal and reached peaks in the summer and autumn in both cities; A- mong these isolates, nucleotide (nt) identities were 89.5%-100.0% whereas amino acid (aa) identities were 95.4%-100.0%. The nt and aa identities were 76.6%-79.7% and 90.4%-92.5% between those strains and the prototype (Gregory) strain of Echo11, respectively. All isolates from Shandong Province were the A genotype and the strains evolved very rapidly, which suggested that several transmission chains was co-circulating. We described the temporal fluctuation and genetic characterization of Echo11 isolates from surveillance of environmental sewage in Shandong Province, thereby providing important information for exploring the dynamic change and genetic variation of circulating human enteroviruses in this Province in China.
Subject(s)
China , Enterovirus B, Human , Classification , Genetics , Phylogeny , Sewage , VirologyABSTRACT
This study aimed to investigate antibody levels of the newer human enteroviruses (EV) A71, A90, and B87 in the population of Shandong Province, and provide a scientific basis for the development of prevention and control measures. In this study, serum specimens were collected from 400 individuals living in Yantai city, Shandong Province in 2010. EV-A71, A90, and B87 antibodies were detected using neutralization tests, and the results were analyzed by statistical methods. It was found that the positive neutralizing antibody rates of EV-A71, A90 and B87 in the population were 46.0%, 8.8%, and 47.0%, respectively. Their geometric mean titers (GMT) were 1 : 5.20, 1 : 1.49, and 1 : 4.02, respectively. Positive antibody rates for EV-A71 and EV-B87 were lowest in the 1-yr and 7-mo age groups, respectively. Positive rates increased gradually with age, and become consistent in the population aged >5 years. Positive antibody rates of EV-A90 were consistent across all age groups. Maternal antibody levels of EV-A71 declined rapidly after birth, and the increase in seroprevalence among 3-7 years old children implied that most EV-A71 infections occurred in preschool and early elementary school children. High positive antibody rates of EV-B87 in healthy individuals, especially children, implied that there may be an immune barrier within the general population. The population monitoring of EV-A90 should be strengthened, as its positive antibody rate is low.
Subject(s)
Adolescent , Adult , Child , Child, Preschool , Female , Humans , Infant , Male , Young Adult , Antibodies, Viral , Blood , China , Epidemiology , Enterovirus A, Human , Classification , Genetics , Allergy and Immunology , Enterovirus Infections , Blood , Allergy and Immunology , Virology , Seroepidemiologic StudiesABSTRACT
Human Enterovirus HEV 74 is a new member of species Human enterovirus B (HEV-B). To understand its evolution and restructuring characteristics, we report the complete genome sequence of a HEV74 strain 05293/SD/CHN/2005(abbreviated as 05293) isolated from an acute flaccid paralysis (AFP) case in Shangdong Province, China, 2005. Analysis of the complete genomic sequence of 05293 showed that its genome was collinear with that of previously described 2 HEV74 strains, except for insertions and deletions at the 5'NTR and the 3 NTR regions. The complete genome sequence of strain 05293 displayed 80. 8% nucleotide and 96% amino acid identity to the prototype strain USA/CA75-10213, and 80. 6% and 95. 9% to another isolated strain Rikaze-136. The P1, P2 and P3 coding regions of strain 05293 displayed 81. 5%, 80. 0%, 79. 7% nucleotide and 95. 9%, 96. 0%, 96.2% amino acid identity to the prototype strain USA/CA75-10213, and 81. 9%, 78. 8%, 79. 5% and 95. 9%, 96. 1%, 95. 7% to strain Rikaze-136, respectively. The phylogenetic tree and Simplot analysis on 05293 and HEV-B genome sequences were performed, and the result indicated frequent recombination within HEV-B.
Subject(s)
Humans , 3' Untranslated Regions , Genetics , 5' Untranslated Regions , Genetics , Base Sequence , China , Enterovirus B, Human , Classification , Genetics , Enterovirus Infections , Virology , Evolution, Molecular , Genome, Viral , Genetics , Muscle Hypotonia , Paralysis , Virology , Phylogeny , RNA, Viral , Genetics , Recombination, Genetic , Sequence Alignment , Sequence Analysis, DNAABSTRACT
To find out whether the mutations of HIV-1 Env have influence on the assembly of pseudovirus and their abilities to infect cells, site-directed mutation (A457D)was performed using cycling mutagenesis and selection of mutants with DpnI. Transformation and plasmid purification technologies were used to obtain mutated env clone. Then both the prototype and the mutant were co-transfected with pSG3(delta(env)) to 293FT cells, respectively. Single-cycle infection assay was employed to analyze the effect of the prototype and the mutant on the ability of functional pseudovirus assembly. The transient expression of both the prototype S12-42-1 and mutant S12-42M were confirmed by Western blot essay. The S/CO value was less than 1 for S12-42-1 and 6.65 for S12-42M, demonstrating the functional pseudovirus was generated only for S12-42M. So mutation on HIV-1 Env has influence on the assembly of pseudovirus and their abilities to infect cells.