Detection and genotype analysis of sapovirus associated with sporadic diarrhea in Shenzhen in 2009 / 南方医科大学学报

<p><b>OBJECTIVE</b>To conduct an epidemiological and genotype analysis of sapovirus (SaV) associated with sporadic diarrhea in Shenzhen in the year 2009.</p><p><b>METHODS</b>A total of 852 fecal samples were collected from sporadic cases of diarrhea in Shenzhen in 2009 and detected by reverse-transcription polymerase chain reaction (RT-PCR) using the primers of SLV5317/5749. The PCR products were analyzed with 1.5% agarose gel electrophoresis and sequenced to construct the phylogenetic tree.</p><p><b>RESULTS</b>Sixteen samples were found positive for SaV, with a positivity rate of 1.88%. Sequence analysis identified 8 isolates as SaV GI genotype (including 3 SaV GI.1 and 5 SaV GI.2), 7 as SaV GIV genotype, and 1 as GII genotype.</p><p><b>CONCLUSIONS</b>SaV infection is present in Shenzhen with GI as the predominant genotype. This is the first report of SaV GIV strains in China, which differs from the strains of Anhui-A141 and Beijing-CHN99/BJ360, suggesting the genotypic variety of SaV infection in China.</p>

Genetic evolution of VP1 of enterovirus type 71 in Shenzhen / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>Genetic evolution of VP1 of enterovirus type 71 in Shenzhen were analyzed.</p><p><b>METHODS</b>All samples were tested by RT-PCR using EV71 specific primer. The VP1 of EV71 were amplified and sequenced. A phylogenetic tree was constructed by comparison of the sequences with subgenotype A, B and C using DNAStar, BioEdit and Mega 3.1 software.</p><p><b>RESULTS</b>Among 35 strains, the homogeneity of the VP1 nucleotide sequence was between 92.1%-100%. The homogeneity of the VP1 nucleotide sequence with subgenotype A and B was between 81.4% -91.1%. The VP1 nucleotide sequence of 35 strains of Shenzhen shared between 93% -97.4% identity with cluster C4. The prevalence strains of EV71 were cluster C4b from 1998 to 2004, and gradually moved to C4a since 2003. All of EV71 were C4b from 2006 to 2008. Also, the homogeneity of the VP1 nucleotide sequence with Anhui FY23 EV71 strain were 94.5% -94.7%, 95.7% -95.8%, 96.2%, 95.4% -97.5%, 96.3% -99.2% from 2003 to 2008. It shows that the homogeneity was increased year by year. There was a mutation (A --> C) at No. 66 nucleotide of VP1 of EV71 that two strains were isolated in 2003 and 8 strains in 2008, that caused amino acid mutation (Q --> H) at No. 22 of VP1.</p><p><b>CONCLUSION</b>EV71 C4b was gradually moved to C4a from 1998 to 2008. There was a missense mutation at No. 66 nucleotide of VP1.</p>

Development of a SPA-ELISA method for detecting anti-coronavirus IgG antibodies in serum samples from fulvous fruit bats / 南方医科大学学报

<p><b>OBJECTIVE</b>To develop an simple and sensitive method for detecting anti-coronavirus IgG antibodies in bat sera based on enzyme-linked immunosorbent assay (ELISA).</p><p><b>METHODS</b>A commercial ELISA kit for detecting SARS-CoV antibody was modified for detecting coronavirus antibodies in bat serum samples. The second antibody in the kit was replaced with horseradish peroxidase-conjugated protein-A (HRP-SPA) based on the characteristics of binding between Staphylococcus aureus protein A (SPA) and mammal IgG Fc fragment. The sera of 55 fulvous fruit bats (Rousettus dasymallus) were tested using the SPA-ELISA.</p><p><b>RESULTS</b>The test results of the positive and negative controls in the kit and the serum samples from convalescent ;patient were consistent with expectation. Coronavirus antibody was detected in 2 out of the 55 bat serum samples. Serum neutralization test confirmed the validity of the SPA-ELISA method.</p><p><b>CONCLUSION</b>This SPA-ELISA method is applicable for detecting coronavirus antibody in bat sera.</p>