Expression of the S glycoprotein of transmissible gastroenteritis virus (TGEV) in transgenic potato and its immunogenicity in mice / 대한수의학회지

Transgenic plants have been tested as an alternative host for the production and delivery of experimental oral vaccines. Here, we developed transgenic potatoes that express the major antigenic sites A and D of the glycoprotein S from transmissible gastroenteritis coronavirus (TGEV-S0.7) under three expression vector systems. The DNA integration and mRNA expression level of the TGEV-S0.7 gene were confirmed in transgenic plants by PCR and northern blot analysis. Antigen protein expression in transgenic potato was determined by western blot analysis. Enzyme-linked immunosorbent assay results revealed that based on a dilution series of Escherichia coli-derived antigen, the transgenic line P-2 had TGEV-S0.7 protein at levels that were 0.015% of total soluble proteins. We then examined the immunogenicity of potato-derived TGEV-S0.7 antigen in mice. Compared with the wild-type potato treated group and synthetic antigen treated group, mice treated with the potato-derived antigen showed significantly higher levels of immunoglobulin (Ig) G and IgA responses.

Sero-surveillance of Transmissible Gastroenteritis Virus (TGEV) and Porcine Respiratory Coronavirus (PRCV) in South Korea

Transmissible gastroenteritis (TGE) is sporadic in South Korea. Since porcine respiratory coronavirus (PRCV) infection was identified in South Korea in 1996, the TGE infection has decreased with the PRCV occurrence. In this study, we described the sero-surveillance of TGE/PRCV infection by using a commercially available ELISA kit. A total of 1,295 sera from slaughtered pigs and 69 sera from wild boars were collected in years 2009 and 2010 throughout the country and tested for antibodies against TGE and PRCV. Although there was no clinical sign observed for TGE and vaccination had not been done for TGEV, 4.9% of sera showed positive for antibody against TGEV. Furthermore, 63.7% of finisher and 8.7% of wild boars were positive for antibody against PRCV. Our result suggests that the TGEV infection might still be present in some farms in South Korea.

Antiviral Activity of Lactobacillus spp. and Polysaccharide

Lactobacillus species have been widely used in both human and animals to prevent or treat gastrointestinal disorders. Recently, it was reported that Lactobacillus spp. inhibited infections by respiratory and gastroenteric viruses; however, its mechanism is not clear. Lactobacillus spp. play direct and indirect roles in the inhibitory effects of viral replication. 1) In vitro study: Highest protection effects were showed with the known probiotics L. rhamnosus GG (LGG) and L. casei Shirota against both rotavirus (RV) and transmissible gastroenteritis virus (TGEV). 2) In vivo study: L. acidophilus had significant immunopotentiating effects, and was therefore recommended for use as a safe oral adjuvant for rotavirus vaccines in pigs. Oral administration of lactobacilli, such as LGG and L. gasseri, might protect a host animal from influenza virus (IFV) infection. Polysaccharides are regarded to be potentially useful and biologically active as an ingredient for pharmaceutical uses due to a variety of biological activities. Especially, sulphated polysaccharides exhibit broad-spectrum antiviral activity against enveloped viruses in vitro. With respect to human immunodeficiency virus type 1 (HIV-1), its in vitro antiviral activity is, specifically, the inhibition of virus-cell attachment, the first step in the infection process. Recently, it was reported that sulphated polysaccharides exhibited antiviral activity against HBV, HCMV, HSV and IFV. In conclusion, Lactobacillus spp. and polysaccharides with antiviral activity against diverse viruses are potential candidates as ingredients for probiotics and medicine candidate for the prevention and treatment of viral infections in animals and humans.

Ocorrência de infecção por parvovírus suíno e gastrenterite transmissível em suínos, criados de forma extensiva, em Goiás / Occurrence of porcine parvoviral infection and transmissible gastroenteritis virus infection in swine from extensive raising systems in the state of Goiás, Brazil

The serological status of porcine parvovirus (PPV) infection and transmissible gastroenteritis virus (TGEV) infection were determined in swine from extensive raising systems in the state of Goiás, Brazil. Ninety-seven serum samples were collected from animals in 12 extensive farms distributed in six cities located nearby Goiânia, GO, and 74 samples were collected from animals in a slaughterhouse in Goiânia, GO. For the PPV-specific antibody detection, the hemaglutination inhibition test (HI) was used; and for TGE antibody detection, the serum neutralization test was performed. Results showed that 25 out of the total 171 (14.4%) analyzed sera were positive for PPV antibodies, and the HI titers varied between 256 to 4,096. None of the 136 serum samples analyzed for TGEV was positive. This is probably the first study that detected PPV and TGEV-specific antibodies in swine herd in the state of Goiás. Data suggest that PPV but not TGEV circulated between and among this population of swine in that state.

Isolation and genomic sequence analysis of porcine transmissible gastroenteritis virus / 病毒学报

A transmissible gastroenteritis virus strain was isolated from suspect samples in Sichuan province and identified by ST cell culture, direct fluorescent antibody test (FA), neutralization test (NT), TME examination and some other methods, then it was named SC-Y. The isolated strain could produce obvious cytopathic effects (CPE), The TCID50 was 10(-3.664)/0.05 mL, The neutralization index is 52.5. cDNA fragments covering the complete genome were amplified by the long reverse transcription PCR. The amplified fragments were further cloned and sequenced. The genome of SC-Y strain was assembled by BioEdit. The length of complete genome was 28590 nucletides, and was composed of 7 ORFs, which was flanked by untranslated regions (UTRs) with 315 bases at the 5'-end and 277 bases at the 3'-end. Phylogenetic analysis based on genome suggested that SC-Y might belong to same subgroup with Purdue strain.