Isolation and Complete Genomic Sequence Analysis of a New Sindbis-like Virus

The Sindbis-like virus was first discovered in China in 1986. Its complete genomic sequence consists of more than 11 000 bp encoding more than 3 700 amino acids. It contains a 5＇ non-transcriptional region （5＇-NTR） in a non-structural region, four non-structural proteins （nsP1, nsP2, nsP3, nsP4） regions, capsids in conserved and non-conserved regions and structural El, E2, E3, 6K regions and a 3＇ non-transcriptional region （3＇-NTR）. The Sindbis-IMB was isolated from the blood of a patient suspected to have encephalitis, and was followed by identification and passage. The virus RNA was extracted from virus supernatant in infected cells and the whole genome was divided into 12 fragments; RT-PCR was then performed to amplify the 12 fragments for complete sequencing. The results showed that the whole genomic sequence of Sindbis-IMB consists of 11 717 bp encoding 3 773 amino acids. Homology comparison with other Sindbis-like isolates demonstrated the highest similarity was the YN87448 with a variation of 1% strain isolated in Yunnan Province and the second highest to the SAAR86 strain with a variation of -1.2%. The nucleotide sequence variations were present in non-structural regions, resulting in amino acids K, E, N, R, H, and L in protein sequences in positions 230, 231,443,781, 1 582, and 1746 in the new isolation respectively. Furthermore, three additional amino acids-glutamic acid, serine and alanine-were noted in nsp4 terminus as compared to the YN87448 isolate

Experimental infection of tree shrews(Tupaia belangeri) with Coxsackie virus A16

Coxsackie virus A16(CA16) is commonly recognized as one of the main human pathogens of hand-foot-mouth disease(HFMD). The clinical manifestations of HFMD include vesicles of hand, foot and mouth in young children and severe inflammatory CNS lesions. In this study, experimentally CA16 infected tree shrews(Tupaia belangeri) were used to investigate CA16 pathogenesis. The results showed that both the body temperature and the percentages of blood neutrophilic granulocytes / monocytes of CA16 infected tree shrews increased at 4-7 days post infection. Dynamic distributions of CA16 in different tissues and stools were found at different infection stages. Moreover, the pathological changes in CNS and other organs were also observed. These findings indicate that tree shrews can be used as a viable animal model to study CA16 infection.

SARS-CoV-2: Vaccines in the pandemic era

Coronavirus disease 2019(COVID-19),caused by the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),has caused millions of infections and deaths worldwide since its emergence in December 2019.As there is little or no natural immunity in the human population or specific anti-COVID-19 drugs,researchers from the government,academia and industry are developing vaccines at an unprecedented speed to halt the pandemic.In this review,the results of animal experiments and clinical trials on several vaccine technical platforms are summarized,and several challenges are also discussed to further promote the development,evaluation and application of vaccines during the challenging situation of the global pandemic.

Confirmed Diagnosis by RT-PCR and Phylogenetic Analysis of Peste des Petits Ruminants Viruses in Tibet, China

This paper reports the confirmed diagnosis by nested RT-PCR of PPR cases in Tibet, China in 2007, and results of phylogenetic analysis. Results showed that the 11 tested samples were PPRV positive by nested RT-PCR, of which 2 samples were genetically close to the X7443 strain (Nigeria 75/1) of lineage I, and 3 samples close to the strain AY560591 (Sungri96) of linage IV with 96.6%、97.3%、97.6% and 98% nucleotide sequence homogeneity respectively, based on partial sequencing of the F gene from 5 samples and complete sequencing of the N/M/F/H genes from one sample. This study suggested that there are at least 2 origins of PPRV in China.

Biological effects of EV71 infection in neural cells

Enterovirus 71 (EV71) can cause serious nervous system lesions but to date the pathogenesis has been unclear. Our results show that EV71 proliferates in the neural cells and leads to neural cell lesions. The study of the pathology of EV71 infection in neonatal rat brains shows that the invasive ability of EV71 to the nervous system in vivo may depend on many unknown factors.