Effect of duck Tembusu virus infection on exosomes of BHK-21 cells / 中国免疫学杂志

Objective:To explore the effect of duck Tembusu virus infection on secretion of exosomes in BHK-21 cells and the pathogenesis of the Tembusu virus.Methods:The exosomes were collected and purified from the culture supernatant of BHK-21 cells infected with duck Tembusu virus AH-F10 strain and the control BHK-21 cells by PEG precipitation method respectively.The purified exosomes were identified by electron microscopy,Western blot assay and mass spectrometry.Results: The classical exosome particle morphology was observed with hyperchromic cup-shaped vesicles and average particle size of 30-160 nm in diameter under transmission electron microscopy.The mean size of the exosome from the infected cells were bigger than the mean size of the exosome from the unin-fected.Western blot assay demonstrated that CD9 and CD63 were detected in purified exosomes as exosome marker molecula.A total of 106 proteins were identified by mass spectrometry assay,84 proteins of infected BHK-21 cells exosome,49 proteins of the uninfected, and the infected and the uninfected BHK-21 share 27 common proteins on exosomes.Conclusion:Duck Tembusu virus infection affect the exosome secretion of cells in connection to the particle size and protein molecular composition.This experiment can lay the foundation for further research of Tembusu virus infection and pathogenesis.

Genetic diversity of porcine sapoviruses from Lulong county in China / 病毒学报

Porcine sapoviruses (SaVs), which belong to the family Caliciviridae, have been considered potential zoonotic agents for human infection, and several cases have been reported in Asian countries. In this study, a total of 200 porcine fecal samples collected from Lulong county of China were tested. Among 200 samples, porcine sapoviruses were detected by RT-PCR in 17 samples (8.5%) showing their circulation in China. 14 out of 17 positive sapovirus strains were genetically related to the genogroup III (GIII) and were further divided into three different clusters or genotypes according to the phylogenetic analysis. In addition, the remaining three sapovirus strains belonged to GVII (one strain) and a potential novel genogroup (two strains) according to the phylogenetic analysis and the nucleotide identity and amino acid identity. These data suggested the genetic diversity of porcine sapoviruses in China.

Characteristics analysis on major genes and the encoded proteins of human G9P8 rotaviruses LL52696 and LL52727 / 病毒学报

Two Rotavirus G9P[8] strains (LL52696 and LL52727) were recognized during a sentinel-based survey in Lulong, China. Phylogenetic analysis of the VP7 gene showed that both strains isolated constituted a divergent genetic cluster distinct from the other G9 strains isolated in China. Analysis of VP4, VP6, and NSP4 genes revealed that these strains were closely related to Lulong strains. We hold that two strains were reassortant between G9 and Lulong predominant strains.

Rotavirus diarrhea among children in three hospitals under sentinel surveillance, from August 2001 to July 2004 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To learn the epidemiologic characteristics of rotavirus diarrhea in three hospitals under sentinel surveillance from August 2001 to July 2004 and to provide background information for developing and implementing rotavirus vaccine.</p><p><b>METHODS</b>Data from hospital-based rotavirus surveillance among children < 5 years old hospitalized with acute diarrhea was used. Patients' clinic information and feces specimens were collected. Specimens were tested and typed for rotavirus.</p><p><b>RESULTS</b>Totally, 3121 specimens were tested and the detection rate of rotavirus was 51%. Among all the children with rotavirus diarrhea, 94% were < 2 years old. G3 (69.9%) was the most prevalent serotype followed by G1 (6.6%) and G2 (2.9%). P[8] was the most common genotype of rotavirus. The most common G-P combination identified in this study was P[8] G3 (64.0%). Seveal other combinations of minor frequency were also identified.</p><p><b>CONCLUSION</b>Rotavirus infection was most commonly seen among children < 5 years old hospitalized with acute diarrhea in the three hospitals. It is important to develop and implement rotavirus vaccine to prevent and control severe rotavirus infection. Because of the diversity of rotavirus strains, it is necessary to perform rotavirus strain surveillance to understand the dynamic nature of viral transmission.</p>

Epidemiological study of human caliciviruses among children with acute diarrhea in Lulong county, 1999 - 2001 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the epidemiological characteristus of human caliciviruses (HuCVs) among children under 5 years of age with acute diarrhea and to estimate the disease burden in Lulong county.</p><p><b>METHODS</b>HuCVs were detected by enzyme linked immunosorbent assay (ELISA) and reverse transcription-polymerase chain reaction (RT-PCR). Some PCR amplicons were cloned and sequenced. Phylogenetic tree was constructed for strain characterization. The rate of HuCVs-attributed hospitalization was estimated according to the positive rate of HuCVs detection in fecal specimens collected from hospitalized diarrhea patients.</p><p><b>RESULTS</b>Between July 1999 and June 2001, 708 fecal specimens were collected, of which 393 rotavirus-negative and 5 rotavirus-positive specimens were detected for HuCVs. Thirty-one point six percentage of fecal specimens from patients with diarrhea was HuCVs positive. Among inpatients, HuCVs positive rate was 17.5%. HuCVs detection was mainly distributed in 3 - 17 mouth-old children, in winter. All 11 strains belonged to NLV GII in which 6 strains GII-3, 2 strains GII-4 and 3 strains GII-7, and they shared 55.1% - 100% nucleotide identity. NLV GII-4 and GII-7 were identified in 2000, while NLV GII-3 and GII-7 in 2001. The preliminary estimate of HuCVs-attributed hospitalization rate was 3.6 per thousand.</p><p><b>CONCLUSION</b>Human caliciviruses with different genotypes circulated among children in Lulong county with GII NLVs were the prevalent strains. The disease burden of HuCVs was second to rotavirus.</p>