Determination of Porcine Rotavirus Serotypes by RT-PCR and RFLP Analysis

G and P tying of group A porcine rotaviruses (P(o)RV) from field fecal samples were performed using reversetranscriptase polymerization chain reaction (RT-PCR) and restriction fragment length polymorphism (RFLP) analysis. After amplifying full length VP7 and partial length VP4 genes, restriction endonucleases were used to digest and analyze the cutting pattern of the gene products. After analysis of digests with restriction endonucleases, seven and six RFLP types were observed for VP7 and VP4, respectively. The G typing analysis of 50 fecal samples revealed that 68% (34/50) were G4, which included G4-like (22/50); 22% (11/50) were G5; 6% (3/50) were G4 and G5 mixed types. The P typing analysis of the same fecal samples revealed that 36% (18/50) were P2B, 52% (26/50) were P9, 1 sample (2%) was a mixture of P2B and P9. Combinations of G and P types, the G4P2B and G4P9 types including G4-like accounted for 26% (13/50) and 32% (16/50), respectively. The G5P2B and G5P9 type also represented 4% (2/50) and 18% (9/50) of the samples. No G3 and G11 or other new P types were identified from the samples tested. Information on the G and P types and G/P combinations in the field fecal samples is useful for developing more effective PoRV vaccines and understanding the epidemiology of PoRV infections in the field.

Expression of the Structural Proteins of Japanese Encephalitis Virus

Japanese encephalitis virus (JEV) is one of the most important human pathogens, which causes the permanent neuropsychiatric sequelae and even fatal diseases with high mortality and morbidity, especially among children. In this study, we expressed the structural proteins (C, prM, and E) of JEV using a Sindbis virus-based heterologous gene expression vector, the pSinRep5. We designed two expression vectors (pSinRep5/JEV C-E and pSinRep5/JEV C-NS1), which encode the precise coding sequence of JEV C-E and JEV C-NS1 proteins, respectively. These cloned JEV structural protein genes were designed to express under the Sindbis virus subgenomic promoter. Upon the transfection and expression of the pSinRep5/JEV C-E or pSinRep5/JEV C-NS1 plasmid, the transfected cells expressed approximately 55 kDa JEV E prtiens. As designed, the JEV NS1 proteins were expressed only in the SinRep5/JEV C-NS1 RNAtransfected cells. In addition, we found in the pSinRep5/JEV C-NS1-transfected cells that the viral proteins were predominantly localized around the perinuclear membranes. On the other hand, cytoplasmic staining was mainly observed in the pSinRep5/JEV C-E RNA-transfected cells in the absence of NS1 protein. Thus, our system will provide a useful tool to dissect intracellular membrane localization signals located in the JEV structural proteins without handling the infectious JEV viral particles and to characterize viral morphogenesis of this pathogen.