Comparison of plaque-forming characteristics and morphogenetic changes of Newcastle disease virus isolated from chickens and geese on host cells / 病毒学报

The plaque-forming characteristics of Newcastle disease viruses of chickens and geese source were compared on various cells. The result showed that there were obvious differences of plaque formation between F48E9 and NA-1 on Vero cells, chicken embryo fibroblast cells (CEF) and goose embryo fibroblast cells (GEF). The plaque-forming ability of NA-1 was higher than F48E9 on GEF, but lower than F48E9 on CEF. On Vero cells, the plaque-forming ability of NA-1 was slightly stronger than F48E9. It demonstrated that the plaque-forming characteristics were consistent with host tropism of virus. The morphogenesis of F48E9 and NA-1 on Vero cells was observed with transmission electron microscope. There were different replication processes between F48E9 and NA-1 on cells at different stages. NA-1 had stronger adaptability to host than F48E9 according to budding processes and envelope integrity.

Isolation and identification of a canine coronavirus strain from giant pandas (Ailuropoda melanoleuca)

Two giant pandas (Ailuropoda melanoleuca) died of unknown causes in a Chinese zoo. The clinical disease profile suggested that the pandas may have suffered a viral infection. Therefore, a series of detection including virus isolation, electron microscopy, cytobiological assay, serum neutralization and RT-PCR were used to identify the virus. It was determined that the isolated virus was a canine coronavirus (CCV), on the basis of coronavirus, neutralization by canine anti-CCV serum, and 84.3% to 100% amino acid sequence similarity with CCV. The results suggest that the affected pandas had been infected with CCV.

Emergency prophylactic effects of the avian influenza virus immunized serum on the infected mice / 中华预防医学杂志

<p><b>OBJECTIVE</b>To evaluate emergency prophylactic effects of the avian influenza virus immunized serum on experimentally infected mice.</p><p><b>METHODS</b>Serum HI antibody titers of 30 mice were detected at day 1 to 19 after being inoculated with 0.2 ml immune serum to estimate half life of immune serum. Ten mice clinical symptom was recorded to estimate the serum security after mice injected 1.5 ml immune serum. Seventy mice were randomly divided into 7 groups according to random number table and inoculated with 0.2 ml, 0.1 ml and 0.05 ml immune serum respectively via intraperitoneal injection on day 8, 4 and 1 prior to challenged with 10 LD(50) influenza virus intranasal. Mice were observed continually for 14 days to calculate the morbidity, mortality, average survival days and compare the lung index and viral titers in lung.</p><p><b>RESULTS</b>Serum HI antibody titers of mice which inoculated with 0.2 ml immune serum maintained 2(6) in 15 days after injection, but drawdown after day 17, the mice injected 1.5 ml immune serum were all alive and none onset. The survival rate of mice which injected 0.2 ml serum on the day 8, 4, 1 before challenge was 80%, 100% and 100%, and the average survival period was 13.1 days, 14.0 days and 14.0 days respectively. The survival rate of mice which injected 0.1 ml and 0.05 ml serum on day 1 before challenge was 100% and 50%, and the average survival days were 14.0 days and 11.7 days respectively. The mice lung index of experimental groups (0.0096 +/- 0.0033 - 0.0145 +/- 0.0060) was smaller than that of viral control group (0.0199 +/- 0.0025), with a statistical significance (P value 0.0022 - 0.0470, < 0.05). The viral titers in lung were significantly decreased by 2 titer as compared to the viral controls.</p><p><b>CONCLUSION</b>The avian influenza virus immunized serum might contain the emergency prophylactic effects and could be developed as an agent for possible human-avian influenza pandemic.</p>

Study on the histopathology of cats inoculated with H5N1 subtype high pathogenic avian influenza virus originated from tigers / 病毒学报

In this study, the HPAIV A/Tiger/Harbin/01/2002 (H5N1) used was originated from tigers and propagated in SPF embryonated hen eggs. TCID5, of the virus was 10(-7.36)/0. 05mL on MDCK cell. The cats were inoculated through bronchus route and then, the cats of dead and control were collected for histopathological and immunohistochemistry examination. Meanwhile, the emulsion supernatant fluid of organs and the pharyngeal swab samples of the dead cats were collected for RT-PCR, survived cats and the control cats were tested for the presence of HI antibody by standard method. The results indicated that the damage of lungs from the dead cats were most obvious, the wide range of red consolidation focus emerged on the lobus pulmonis, the fused focus of infection caused injury of lungs. Histology under the microscope revealed diffuse alveolar damage, confluence phlegmasia pathology, infiltration of lymphomonocytes, sackful of infiltration of macrophages and manipulus protein-like effusion in the alveolar. By immunohistochemistry, the positively stained virus particles were found on the epithelial cells of bronchus and alveolus, and also in the endochylema of lymphomonocytes. The specific electophoretic band of 464bp amplified by RT-PCR from samples of pharyngeal swabs, lungs, kidneys, hearts and brains was as same as the theory value. HI antibody titers of the survived cat were 1:32.

Selection of recombinant fowlpox virus coexpressing HIV-1 gag-gp120 and IL-6 / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To construct the recombinant fowlpox virus (rFPV) coexpressing HIV-1 gag-gp120 and hIL-6.</p><p><b>METHODS</b>The recombinant expressing plasmid pUTA-GE-IL6 was successfully constructed by inserting gag-gp120 gene and hIL-6 gene into the downstream of the combined promoter ATI-p7.5 and p7.5 tandem promoter respectively. After transfecting the plasmid into chicken embryonic fibroblast (CEF) cells preinfected with FPV 282E4 strain and selecting the recombinant virus under the pressure of BUdR. The recombinant virus was analyzed by nucleic acid probe hybridization and immunoblotting. In addition, the formation of virus-like particle and the expression of interested proteins in the recombinant virus-infected p815 cells were observed, and the immunogenicity of the recombinant virus was also analyzed.</p><p><b>RESULTS</b>There was colorable dot for the positive recombinant virus, immunoblotting analysis showed that the recombinant virus could expressed both gag-gp120 and IL-6. Virus-like particles (VLP) were formed in virus-infected cells, and the interested proteins could be expressed in mammalian cells infected by the recombinant virus. The immunity index from the immunized mice showed that the recombinant virus had good immunogenicity.</p><p><b>CONCLUSION</b>The recombinant fowlpox virus coexpressing gag-gp120 and IL-6 was successfully constructed, which may provide basis for the preparation of live vector genetic engineering vaccine and macromolecule particle vaccine against HIV-1.</p>