Analysis of human metapneumovirus genotype in Hunan, China and its attachment protein G sequence character / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To understand the genotypes of human metapneumovirus (hMPV) and the genetic character of hMPV attachment protein G sequence in Hunan, China.</p><p><b>METHODS</b>232 nasopharyngeal aspirates (NPA) samples from hospitalized children with acute respiratory infections were collected from Hunan, China in 2005. HMPV was detected. The full length of G glycoprotein genes were amplified and sequenced. Bioinformatics soft-wares were employed to analyze the sequences.</p><p><b>RESULTS</b>17/232 (7.3%) were showed hMPV positive. And co-infection rate with other viruses is 35%. The diagnoses of these hMPV positive cases are pneumonia, bronchiolitis and bronchopneumonia. Phylogenetic analysis for G genes from 13 hMPVs revealed the existence of four major subgroups: A1, A2, B1, B2 in Hunan, China in 2005. There are four types of sequence lengths of hMPV G glycoprotein, which are 711, 675, 660, 696nt. It is different in potential N-linked glycosylation sites and number of cysteine residues among these hMPVs of Hunan, China and Beijing, China. Also it is different from those in Japan and North America.</p><p><b>CONCLUSION</b>The investigation of hMPV from Hunan, China in 2005 revealed the high speed of genetic variation and the marked character of geographic epidemic differences.</p>

Evaluation of reverse transcription loop-mediated isothermal amplification for detection of avian influenza A H5N1 virus / 病毒学报

A simple and sensitive Reverse Transcription Loop-mediated Isothermal Amplification (RT-LAMP) method was established to provide a new alternative for clinical diagnosis of Avian influenza A H5N1 virus. The method employed a set of six specially designed primers that recognized eight distinct sequences of the target for amplification of nucleic acid under isothermal conditions. In current study, fifty-one experimentally infected animal specimens and viral cultures that had been tested were analyzed by RT-LAMP for NA gene and HA gene, respectively. The amplification process of LAMP was monitored in real-time by the addition of SYBR Green dye. Meanwhile, the result showed high correlation between nested PCR and RT-LAMP. The specificity of the RT-LAMP assay was confirmed by restriction enzyme digestion analysis and sequencing of the amplified product. When the sensitivity of this assay was tested by serial 10-fold dilutions of RNA molecules from specimens, it was found that the RT-LAMP method achieved theoretically a sensitivity of 10 RNA molecules. Thus, we concluded that the RT-LAMP assay has potential usefulness for rapid detection of the Avian influenza A H5N1 virus.

Genome cloning and phylogenetic analysis of human bocavirus capsid gene / 病毒学报

The full-length genome of one human bocavirus (HBoV) and the VP1 sequences of nine HBoV were amplified from patients' samples by PCR, cloned into pGEM-T vector separately, and sequenced. In this study, the one full length gemome and nine VP1 sequences of HBoV were aligened with 14 sequences of Parvoviruses which were canonical exemplars in Parvovirinae. Phylogenetic analysis showed that HBoV capsid sequences positioned closely to B19 parvovirus, although they positioned far in phylogenetic tree based on full length genome. Many similarities were found between HBoV and B19 in capsid by alignment on secondary structural elements. Because both B19 and HBoV are the only Parvoviruses that infect mankind, so study on HBoV may be used for reference to B19 which had been studied for about 30 years. By analysis of mutational sites, HBoV capsid protein showed a highly conserved secondary structural elements, but highly active in VP1-U, leading end of VP2 and insertions between the strands of the betaG-H. This cued that HBoV inclined to immune evasion and infectant adaptive faculty.