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Ge S.Q.,China Animal Health and Epidemiology Center
Bing du xue bao = Chinese journal of virology / [bian ji, Bing du xue bao bian ji wei yuan hui] | Year: 2013

Virus-like particles (VLPs) are composed of multiple copies of one or more expressed recombinant viral structural proteins which spontaneously assemble into particles upon expression. VLPs are non infectious because they assemble without incorporating genetic material. VLPs have structural characteristics and antigenicity similar to the parental virus because they mimick the wild-type virus structure. Hence, they are recognized readily by the immune system which induces strong anti-viral immune responses to stop virus infection. VLPs have therefore shown dramatic effectiveness as candidate vaccines and diagnostic reagent for virus. Here, in order to provide reference to the research of influenza VLPs, we reviewed the current research progress of influenza VLPs, and discussed the characteristics associated with producing VLPs for influenza virus. Source

Zhang J.,North University of China | Jin Z.,North University of China | Sun G.,North University of China | Sun X.,China Animal Health and Epidemiology Center | Ruan S.,University of Miami
Bulletin of Mathematical Biology | Year: 2012

Human rabies, an infection of the nervous system, is a major public-health problem in China. In the last 60 years (1950-2010) there had been 124,255 reported human rabies cases, an average of 2,037 cases per year. However, the factors and mechanisms behind the persistence and prevalence of human rabies have not become well understood. The monthly data of human rabies cases reported by the Chinese Ministry of Health exhibits a periodic pattern on an annual base. The cases in the summer and autumn are significantly higher than in the spring and winter. Based on this observation, we propose a susceptible, exposed, infectious, and recovered (SEIRS) model with periodic transmission rates to investigate the seasonal rabies epidemics. We evaluate the basic reproduction number R 0, analyze the dynamical behavior of the model, and use the model to simulate the monthly data of human rabies cases reported by the Chinese Ministry of Health. We also carry out some sensitivity analysis of the basic reproduction number R 0 in terms of various model parameters. Moreover, we demonstrate that it is more reasonable to regard R 0 rather than the average basic reproduction number R̄ 0 or the basic reproduction number R̂ 0 of the corresponding autonomous system as a threshold for the disease. Finally, our studies show that human rabies in China can be controlled by reducing the birth rate of dogs, increasing the immunization rate of dogs, enhancing public education and awareness about rabies, and strengthening supervision of pupils and children in the summer and autumn. © 2012 Society for Mathematical Biology. Source

Wang K.,China Animal Health and Epidemiology Center
Wei sheng wu xue bao = Acta microbiologica Sinica | Year: 2012

To learn about the function and gene phylogenetic relationship of the conserved regions in capsular polysaccharides synthesis (CPS) locus, based on the CPS locus sequence of Streptococcus suis serotype 1, 2, 7 and 9 and the results to the cross-hybridization experiments, the CPS locus of Streptococcus suis was hypothesized as cassette-like structure which is similar to Streptococcus pneumoniae. PCR, sequencing and southern blotting was used to certify the hypothesis. The CPS locus of Streptococcus suis was cassette-like structure. The 5'-end of the CPS locus contained 4 regulatory genes which are highly similar in all the serotypes. The flanking genes of the CPS locus are conservative. The flanking gene aroA, which is at the downstream to the CPS locus, was selected as the objective gene to develop the PCR to amplify the serotype-specific regions. The orfY, orfX, cpsA, cpsB, cpsC, cpsD and aroA are conserved with high sequence identity in different serotypes. Source

Liu H.L.,China Animal Health and Epidemiology Center
Bing du xue bao = Chinese journal of virology / [bian ji, Bing du xue bao bian ji wei yuan hui] | Year: 2010

Mutation in any of five key amino acid residues (at positions 26, 27, 30, 31 and 34) within the M2 protein of influenza A viruses leads to resistance against the amantodine class of anti-influenza drugs. In this study, a pyrosequencing method was described to rapidly detect established five molecular markers of resistance to M2 blockers, amantadine. The residues L26, V27, A30, S31 and G34 in the M2 protein were targeted for pyrosequencing, and 94 avian influenza viruses were used to perform the amantadine resistance analysis. Our results showed that most of avian influenza viruses were amantadine resistant, Mutations V27I and S31N were founded in these isolates. Source

Chen Y.X.,China Animal Health and Epidemiology Center
Bing du xue bao = Chinese journal of virology / [bian ji, Bing du xue bao bian ji wei yuan hui] | Year: 2012

Based on the genomic sequence of NDV08-004 strain (GenBank accession number FJ794269), seven pairs of primers were designed to amplify the genomic fragments by RT-PCR and cloned into pGEM-Teasy vector. The fragments (named A to G) were sub-cloned into transcription vector pOLTV5 according to the universal RE site and the plasmid named NDV08-004-pO which contained the full length cDNA of NDV08-004 strain was constructed. Three helper plasmids (pCI-NP, pCI-P and pCI-L) together with NDV08-004-pO were co-transfected into BSR T7/5 cells, and the transfection supernatant was inoculated into SPF embryonated eggs to rescue the virus. The virus was rescued successfully and identified by HA and RT-PCR and sequencing. The rescue system constructed in this study provided a good foundation for the further related research. Source

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