Effects of Vaccination with the C-Strain Vaccine on Immune Cells and Cytokines of Pigs Against Classical Swine Fever Virus.

The attenuated C-strain vaccine against classical swine fever virus (CSFV) is one of the safest and most effective attenuated vaccines. However, little is known of the host immune response after vaccination with the C-strain vaccine. Blood samples from vaccinated pigs were collected to evaluate the number of immune cells, the level of specific CSFV antibody, and related cytokines induced by the vaccination of C-strain vaccine.

Complete Genome Sequence of a Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus Variant with a New Insertion in Glycoprotein 5, Isolated from a Stillborn Fetus.

Here, we report the complete genome sequence of strain GD-2011, a highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) that was isolated from a stillborn fetus. The GD-2011 strain is characterized by a discontinuous 30-amino acid deletion in the nonstructural protein 2. In addition, GD-2011 had a 1-amino acid insertion in glycoprotein 5, which does not exist in any other HP-PRRSV strains.

Rapid and sensitive detection of PRRSV by a reverse transcription-loop-mediated isothermal amplification assay.

A real-time monitoring reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for the sensitive and specific detection of prototypic, prevalent North American porcine reproductive and respiratory syndrome virus (PRRSV) strains. As a higher sensitivity and specificity method than reverse transcription polymerase chain reaction (RT-PCR), the RT-LAMP method only used a turbidimeter, exhibited a detection limit corresponding to a 10(-4) dilution of template RNA extracted from 250 μL of 10(5) of the 50% tissue culture infective dose (TCID(50)) of PRRSV-containing cells, and no cross-reactivity was observed with other related viruses including porcine circovirus type 2, swine influenza virus, porcine rotavirus and classical swine fever virus. From forty-two field samples, 33 samples in the RT-LAMP assay was detected positive, whereas three of which were not detected by RT-PCR.

Development of a loop-mediated isothermal amplification assay for porcine circovirus type 2.

In this study, the loop-mediated isothermal amplification (LAMP) method was used to develop a rapid and simple detection system for porcine circovirus type 2 (PCV2). According to the PCV2 sequences published in GenBank, multiple LAMP primers were designed targeting conserved sequences of PCV2. Using the DNA extracted from PCV2 isolates HUN-09 and SD-09 as the template, LAMP reactions in a PCV2 LAMP system was performed, the amplification products were detected by adding SYBR Green I and could be observed directly by the naked eye.

[Distributions of pathogenic capsular types and in vitro antimicrobial susceptibility of different serotypes of Streptococcus suis isolated from clinically healthy sows from 10 provinces in China].

Objective: To determine the distributions of major pathogenic capsular types and in vitro antimicrobial susceptibility of different serotypes of Streptococcus suis isolated from clinically healthy sows in China.

Methods: Tonsil specimens of clinically healthy sows from 10 different provinces in China were collected, a total of 421 S. suis were isolated.

[Research of real-time fluorescent PCR in the rapid differential detection of H5, H9, H7 subtype avian influenza inactivated vaccines].

Specific primers and TaqMan MGB probes were designed with Primer Express 2.0 software according to the conserved region of the H5, H9, H7 subtype AIV hemagglutinin gene to make research of real-time fluorescent one-step PCR in the differential detection of H5, H9, H7 subtype avian influenza inactivated vaccines. The result showed that the method was specific and reproducible.

Cloning and expression of interferon-alpha/gamma from a domestic porcine breed and its effect on classical swine fever virus.

To further evaluate the clinical impact of recombinant PoIFN-alpha/gamma, PoIFN-alpha/gamma genes from a Chinese domestic big-white porcine breed were cloned using PCR, and expressed in a high-level prokaryotic system. The antiviral activities of rPoIFN-alpha/gamma on vesicular stomatitis virus (VSV), porcine reproductive and respiratory syndrome virus (PRRSV), and classical swine fever virus (CSFV) were investigated in different cell lines. The cloned PoIFN-alpha gene encodes a protein of 166 amino acids and has been named PoIFN-alphac.