Research Advances in the Porcine Deltacoronavirus / 病毒学报

The deltacoronavirus is a new member of the subfamily Coronaviridae of the family Coronaviridae. Deltacoronaviruses can infect birds and mammals. Deltacoronaviruses were detected in early 2007 in Asian leopard cats and Chinese ferret badgers. In 2014, porcine deltacoronavirus (PDCoV) infection spread rapidly in the USA. Moreover, cell culture-adapted PDCoV has been obtained from infected piglets. Animal experiments have confirmed that the isolated PDCoV is highly pathogenic and causes severe diarrhea in piglets. Thus, the PDCoV can be considered to be a good model to study the deltacoronavirus. In this review, we discuss the etiology, epidemiology, pathogenicity, culture, and diagnostic methods of the PDCoV.

The development and application of the latex agglutination test to detect serum antibodies against Japanese encephalitis virus.

The attenuated SA14-14-2 strain of Japanese encephalitis virus (JEV) was cultured in BHK-21 cells. The viral supernatant was purified and concentrated with PEG (MW 20,000). A suitable concentration of JEV antigen was used to sensitize latex to prepare the latex antigen. The specificity, sensitivity and stability of the antigen were assessed. A latex agglutination test (LAT) was developed for rapidly detecting antibody against JEV infection. The LAT and haemagglutination inhibition (HI) assay were compared by simultaneously testing 35 porcine serum samples from five farms. Ninety per cent (20/23) of the samples were seropositive by both assays. No significant difference was found between the two methods (p > 0.05). Furthermore, when 1,613 porcine sera from 120 farms were tested by LAT, the number of positive sera was 652, while that of negative sera was 961, ranging from 20% to 50% positive throughout the year. These results indicate that LAT is an appropriate candidate method for epidemiological surveys for and diagnosis of Japanese encephalitis.