Sequence analysis of the spike gene of Porcine epidemic diarrhea virus isolated from South China during 2011–2015

The spike gene of porcine epidemic diarrhea virus (PEDV) was sequenced from 55 South China field strains isolated from pigs with symptoms of diarrhea. The sequences were compared within the set of field strains as well as with reference strains available in GenBank. Within the 55 South China PEDV field strains, the deduced amino acid sequence identities ranged from 93.8% to 99.9 % and ranged from 90.7% to 99.5% when compared with the foreign reference strains in GenBank. Our phylogenetic analysis showed that 10 of the 55 South China PEDV strains belonged to G1b and 45 belonged to G2b.

Genetic diversity and phylogenetic analysis of porcine reproductive and respiratory syndrome virus in southern China from 2007 to 2014

Porcine reproductive and respiratory syndrome virus (PRRSV) has a high degree of genetic variation. In this study, we characterized the genetic variation and evolutionary relationships among circulating PRRSV strains in southern China. We analyzed 29 NSP2 strains and 150 ORF5 strains from clinical samples collected in southern China during 2007–2014. The alignment results showed that the nucleotide identity similarities of the two genes among these strains were 80.5%–99.7% and 80.9%–100%, respectively. Phylogenetic analysis based on the NSP2 gene showed that highly pathogenic (HP)-PRRSV was still the dominant virus in southern China from 2013 to 2014. Compared with reference strains CH-1a and VR-2332, the field strain 131101-GD-SHC, which shared high homology with JXA1-P170, had a novel 12 amino acid deletion at position 499–510. Phylogenetic analysis based on the ORF5 gene showed that HP-PRRSV, VR2332-like strains, and QYYZ-like strains were simultaneously circulating in southern China from 2007 to 2014, suggesting that, in recent years, the type 2 PRRSV was more diverse in southern China. In conclusion, mutations in the decoy epitope and primary neutralizing epitope could be markers of viral evolution and used to study evolutionary relationships among PRRSV strains in China.

Molecular characterization and phylogenetic analysis of pseudorabies virus variants isolated from Guangdong province of southern China during 2013–2014

Outbreaks of pseudorabies (PR) have occurred in southern China since late 2011, resulting in significant economic impacts on the swine industry. To identify the cause of PR outbreaks, especially among vaccinated pigs, 11 pseudorabies virus (PRV) field strains were isolated from Guangdong province during 2013–2014. Their major viral genes (gE, TK, gI, PK, gD, 11K, and 28K) were analyzed in this study. Insertions or deletions were observed in gD, gE, gI and PK genes compared with other PRV isolates from all over the world. Furthermore, sequence alignment showed that insertions in gD and gE were unique molecular characteristics of the new prevalent PRV strains in China. Phylogenetic analysis showed that our isolates were clustered in an independent branch together with other strains isolated from China in recent years, and that they showed a closer genetic relationship with earlier isolates from Asia. Our results suggest that these isolates are novel PRV variants with unique molecular signatures.

Effects of matrine on proliferation and apoptosis of human renal cell carcinoma cell line GRC-1 / 中西医结合学报

OBJECTIVE: To observe the effects of matrine on proliferation and apoptosis of human renal cell carcinoma cell line GRC-1 in vitro, and to explore its mechanism. METHODS: The human renal cell carcinoma cell line GRC-1 was treated with matrine of different concentrations for 24, 48, 72 and 96 h respectively. The MTT assay was used to evaluate the cytotoxic effects of matrine on GRC-1 cells. The transmission electron microscope and flow cytometry were utilized to observe and detect the apoptosis of GRC-1 cells induced by matrine. The expression levels of Bcl-2 and Bax proteins were evaluated by streptavidin-biotin-peroxidase method. RESULTS: The matrine of different concentrations all have cytotoxic effects on GRC-1 cells, with obvious dose- and time-dependent effects. The apoptosis induced by matrine was confirmed in GRC-1 cells. With intervention of matrine (1.5 g/L) for 12 h, the expression level of Bcl-2 in GRC-1 cells was decreased while the expression level of Bax was increased as compared with those in the untreated group. CONCLUSION: The proliferation-inhibiting effects of matrine on human renal cell carcinoma cell line GRC-1 may be related to down-regulating the ratio of Bcl-2/Bax protein expression and promoting the apoptosis.