Neutralizing monoclonal antibodies against porcinophilic foot-and-mouth disease virus mapped to antigenic site 2 by utilizing novel mutagenic virus-like particles to detect the antigenic change.

In the case of serotype O foot-and-mouth disease virus (FMDV), antibodies against five neutralizing sites play a pivotal role in protection of animals, with site 1 being considered the most crucial. However, recent studies indicated that the antibodies of vaccinated farm animals are mainly against site 2 rather than site 1. In Taiwan, blanket vaccination had been implemented for more than fifteen years, in which the porcinophilic isolate O/Penghu/2012 showed significant amino acid alterations in site 2 compared to the early isolate O/TW/97.

Evolutionary histories of coxsackievirus B5 and swine vesicular disease virus reconstructed by phylodynamic and sequence variation analyses.

Coxsackievirus (CV)-B5 is a common human enterovirus reported worldwide; swine vesicular disease virus (SVDV) is a porcine variant of CV-B5. To clarify the transmission dynamics and molecular basis of host switching between CV-B5 and SVDV, we analysed and compared the VP1 and partial 3D gene regions of these two viruses. Spatiotemporal dynamics of viral transmission were estimated using a Bayesian statistical inference framework.

Direct coating of culture medium from cells secreting classical swine fever virus E2 antigen on ELISA plates for detection of E2-specific antibodies.

The envelope glycoprotein E2 of classical swine fever virus (CSFV) is widely used as a marker for measuring vaccine efficacy and antibody titer. The glycosylation profile of E2 may affect the immunogenicity of the vaccine and the timing of re-vaccination. In this study, a human embryonic kidney cell line was used to secrete fully-glycosylated CSFV E2, which was then coated onto ELISA plates without purification or adjustment.

Development of a multiplex Luminex assay for detecting swine antibodies to structural and nonstructural proteins of foot-and-mouth disease virus in Taiwan.

Background/purpose(s): Foot-and-mouth disease (FMD) and swine vesicular disease (SVD) are serious vesicular diseases that have devastated swine populations throughout the world. The aim of this study was to develop a multianalyte profiling (xMAP) Luminex assay for the differential detection of antibodies to the FMD virus of structural proteins (SP) and nonstructural proteins (NSP).

Methods: After the xMAP was optimized, it detected antibodies to SP-VP1 and NSP-3ABC of the FMD virus in a single serum sample.

Development of a Luminex assay for the detection of swine antibodies to non-structural proteins of foot-and-mouth disease virus.

Foot-and mouth disease (FMD), swine vesicular disease (SVD), and vesicular stomatitis (VS) are highly contagious vesicular diseases of swine but are not easy to differentiate clinically. For the purpose of instant detecting of FMD and differentiating it from the other vesicular diseases, a Luminex assay was developed. Sera from 64 infected, 307 vaccinated, and 280 naïve pigs were tested by the Luminex assay.

Differentiation of foot-and-mouth disease-infected pigs from vaccinated pigs using antibody-detecting sandwich ELISA.

The presence of serum antibodies for nonstructural proteins of the foot-and-mouth disease virus (FMDV) can differentiate FMDV-infected animals from vaccinated animals. In this study, a sandwich ELISA was developed for rapid detection of the foot-and-mouth disease (FMD) antibodies; it was based on an Escherichia coli-expressed, highly conserved region of the 3ABC nonstructural protein of the FMDV O/TW/99 strain and a monoclonal antibody derived from the expressed protein. The diagnostic sensitivity of the assay was 98.

Development of a chromatographic strip assay for detection of porcine antibodies to 3ABC non-structural protein of foot-and-mouth disease virus serotype O.

A chromatographic strip assay was developed for rapid detection of serum antibodies to non-structural protein of foot-and-mouth disease virus. The assay was based on Escherichia coli-expressed 3ABC non-structural protein and an immunochromatographic technique, which shortened the detection time to about one hour. The sensitivity of the assay was determined to be 96.

Development of a reverse transcription multiplex real-time PCR for the detection and genotyping of classical swine fever virus.

A reverse transcription multiplex real-time PCR (RT-MRT-PCR) was developed for rapid detection and genotyping of classical swine fever virus (CSFV). The universal primers and specific TaqMan probes for each of the three genotypes, genotypes 1, 2, and 3, were designed within the 3'-UTR of the CSFV. Non-CSFV swine virus and clinical samples from specific pathogen-free (SPF) pigs were both demonstrated to be CSFV-negative by RT-MRT-PCR.

Rapid detection and differentiation of wild-type and three attenuated lapinized vaccine strains of classical swine fever virus by reverse transcription polymerase chain reaction.

A simple one-step reverse transcription polymerase chain reaction (RT-PCR) method was developed based on T-rich insertions in the viral genome for simultaneous detection and differentiation of wild type and vaccine strains of Classical swine fever virus (CSFV). The CSFV-specific primers were designed to contain the sequences of the T-rich insertion sites that exist uniquely in the 3' nontranslated regions (3' NTR) of the genome of lapinized CSFV vaccine strains. By using a one-step RT-PCR or a nested PCR followed by an agarose gel electrophoresis or a multicapillary electrophoresis, the wild-type and lapinized vaccine strains of CSFV in clinical samples could be detected and accurately distinguished.

Genetic variation in open reading frame 5 gene of porcine reproductive and respiratory syndrome virus in Taiwan.

In an effort to understand the genetic variation in porcine reproductive and respiratory syndrome virus (PRRSV) isolates in Taiwan, 40 isolates obtained between 2004 and 2006 were analyzed for their sequences of open reading frame 5. After reverse transcription polymerase chain reaction, the amplified open reading frame 5 fragments were analyzed by restriction fragment length polymorphism and sequence comparison. The results showed that all the Taiwanese isolates belonged to the North American genotype.

Sex identification of owls (family Strigidae) using oligonucleotide microarrays.

Molecular sexing of the diversified avian family Strigidae is difficult. Sex identification using the intron length difference between W and Z chromosomal CHD1 genes, as visualized by agarose gel electrophoreses, often produces ambiguous results. Here we describe a simple method for sexing a variety of Strigidae species using oligonucleotide microarrays, on which several sex-specific probes operated complementarily or in concert.

Simultaneous detection and differentiation of Newcastle disease and avian influenza viruses using oligonucleotide microarrays.

Newcastle disease (ND) and avian influenza (AI) are two of the most important zoonotic viral diseases of birds throughout the world. These two viruses often have a great impact upon the poultry industry. Both viruses are associated with transmission from wild to domestic birds, and often display similar signs that need to be differentiated.