Prevalence of Antibodies against Transmissible Gastroenteritis Virus and Porcine Respiratory Coronavirus among Pigs in Six Regions in Japan

Abstract

ABSTRACT. A total of 2,703 pig sera from 171 farms in six regions in Japan were screened for virus-neutralizing (VN) antibody against transmissible gastroenteritis virus (TGEV). Although none of the farms had clinical signs of transmissible gastroenteritis (TGE) or vaccination against TGEV, VN antibody was detected in 14.4% of sera at 30 farms (17.5%) across all six regions. On testing of 263 VN antibody-positive sera from 27 farms with a commercial blocking ELISA to distinguish TGEV and porcine respiratory coronavirus (PRCV) antibodies, 78.3% were positive for PRCV antibody only, while 12.5% were positive for TGEV antibody only or both TGEV and PRCV antibodies. Seven of the eight TGEV antibody-positive farms were also positive for PRCV antibody. Five months after the antibody examination, a TGE outbreak occurred at one of these seven farms. These results suggest that most of the detected VN antibodies were to PRCV, and that TGEV infection might be present at some PRCV-positive farms in Japan.

Prevalence of antibodies against transmissible gastroenteritis virus (TGEV) in Hungary

“…This difference is recognized minimal at the genetic level, which explains how both viruses are considered as one species Alphacoronavirus 1 (Lin et al, 2015), but it can be great phenotypically, as it may be the result of their different tissue tropism, as the expressed S glycoprotein is responsible for cell entry (Ballesteros, Sanchez, & Enjuanes, 1997). In contrast to TGEV, PRCV has respiratory tropism and usually causes an undiscerned subclinical infection (Pensaert, Cox, Van Deun, & Callebaut, 1993), which can induce the production of cross-reacting antibodies, causing difficulties in serological diagnostics (Miyazaki, Fukuda, Kuga, Takagi, & Tsunemitsu, 2010). The virus neutralization assay cannot be used to differentiate TGEV and PRCV, therefore various enzyme-linked immunosorbent assays (ELISA) were developed using monoclonal antibodies targeting the different epitopes of the S protein (Carman et al, 2002).…”

Sporadic re-emergence of enzootic porcine transmissible gastroenteritis in Hungary

“…Although we have no direct proof of this assumption, namely that the presence of PCV is responsible for the TGEV problem, serological results (Table 1) showed that primiparous pigs may remain seronegative for both TGEV and PRCoV. Similar increases of TGE incidence have been reported from Japan (Miyazaki et al, 2010) and China (Wang et al, 2013), the world's largest pork producer.…”

“…However, occasional reports of TGEV-specific seropositivity (Elvander et al, 2000;Brendtsson et al, 2006;Roic et al, 2012) and even sporadic outbreaks in different parts of the world (Pritchard et al, 1999;Kim et al, 2000;Miyazaki et al, 2010;Wang et al, 2010) indicate that TGE cannot be neglected, as the virus is still present in pig herds, although mostly without clinical manifestations.…”

Transmissible gastroenteritis virus: Identification of M protein-binding peptide ligands with antiviral and diagnostic potential

“…Despite the availability of commercial vaccines, TGE still poses a regional threat to the swine industry due to the high morbidity and mortality that TGEV causes in suckling piglets under 2 weeks of age (Miyazaki et al, 2010). Although passive, lactogenic immunity induced by virulent or attenuated TGEV vaccines can provide effective protection, sufficient risk remains.…”

“…Three experimental approaches were used to evaluate the antiviral activity of pepTGEV-M7 (Miyazaki et al, 2010;Ren et al, 2011b). First, to assess the ability of the peptide to bind TGEV in vitro, 100 TCID50 of TGEV was pre-incubated with pepTGEV-M7 at 500, 250, 125, 62.5 or 31.25 lg/ml before infecting ST cells.…”