Cross-species transmission of an emerging porcine circovirus (PCV4): First molecular detection and retrospective investigation in dairy cows.

Porcine circovirus 4 (PCV4), a novel porcine circovirus identified in pigs, has recently been proved to be pathogenic to piglets. However, little is known about its cross-species transmission, and demonstration of PCV4 in dairy cows is lacking. To explore whether the PCV4 genome exists in dairy cows, 1170 fecal samples were collected from dairy farms in 7 cities in Henan Province of China during 2012-2021, and screened by qPCR for the presence of PCVs (PCV2-PCV4).

Modulation of Gut Microbiota, Short-Chain Fatty Acid Production, and Inflammatory Cytokine Expression in the Cecum of Porcine Deltacoronavirus-Infected Chicks.

Porcine deltacoronavirus (PDCoV) is a novel swine enteropathogenic coronavirus that causes watery diarrhea and induces proinflammatory cytokine responses in piglets. Our previous research showed that the specific-pathogen-free (SPF) chicks exhibited mild diarrhea and low fecal viral shedding, along with cecum lesions after PDCoV infection. Disturbances in the homeostasis of the gut microbiota have been associated with various diseases.

Porcine deltacoronavirus infection alters bacterial communities in the colon and feces of neonatal piglets.

Porcine deltacoronavirus (PDCoV) is a novel enteropathogenic coronavirus that causes watery diarrhea in piglets. Little is known regarding the alteration of the gut microbiota in PDCoV-induced diarrhea piglets. In this study, 5-day-old piglets were experimentally infected with PDCoV strain CH-01, and all piglets developed typical clinical disease, characterized by acute and severe watery diarrhea.

A nano silicon adjuvant enhances inactivated transmissible gastroenteritis vaccine through activation the Toll-like receptors and promotes humoral and cellular immune responses.

Inactivated transmissible gastroenteritis virus (TGEV) vaccines are widely used in swine herds in China. These are limited, however, by the need to elicit both humoral and cellular immunity, as well as the efficiency of adjuvants. In this study, a 70-nm nano silicon particle was applied with inactivated TGEV vaccine in mice, and its immune-enhancing effects and mechanism of action investigated.

Porcine parvovirus infection activates inflammatory cytokine production through Toll-like receptor 9 and NF-κB signaling pathways in porcine kidney cells.

Porcine parvovirus virus (PPV) is an animal virus that has caused high economic losses for the swine industry worldwide. Previous studies demonstrated that PPV infection induced significant production of interleukin 6 (IL-6) in vitro and in vivo. However, the inflammatory cytokines and specific signaling pathways induced during PPV infection remain largely unknown.

Construction and immunogenicity of a recombinant pseudorabies virus co-expressing porcine circovirus type 2 capsid protein and interleukin 18.

A novel recombinant pseudorabies virus (PRV) expressing porcine circovirus type 2 (PCV2) capsid protein and IL-18 was constructed. The PCV2 open reading frame 2 (ORF2) and porcine IL-18 genes were amplified by PCR and then inserted into the PRV transfer vector (pG) to produce a recombinant plasmid (pGO18). Plasmid pGO18 was transfected into porcine kidney cell (PK15) pre-infected with PRV HB98 vaccine strain to generate a recombinant virus.

Molecular detection and genomic characterization of Torque teno sus virus 1 and 2 from domestic pigs in central China.

In the present study, Torque teno sus viruses (TTSuVs) were detected in tissue and blood samples obtained from domestic pigs in central China, and complete genomes of TTSuVs were characterized. A total of three tissue samples (3/20, 15 %) from post-weaning multisystemic wasting syndrome-affected pigs and 30 blood samples (30/40, 75 %) from healthy pigs were positive for Torque teno sus virus 1 (TTSuV1) and/or 2 (TTSuV2). Two TTSuV strains (TTV1Hn54 and TTV2Hn93) comprising 2,794 and 2,875 nucleotides, respectively, each had four open reading frames (ORFs) and the untranslated region with TATA box and GC-rich region.

Simultaneous detection of porcine parvovirus and porcine circovirus type 2 by duplex real-time PCR and amplicon melting curve analysis using SYBR Green.

The development of a SYBR Green-based duplex real-time PCR is described for simultaneous detection of porcine parvovirus (PPV) and porcine circovirus type 2 (PCV-2) genomes. Viral genomes were identified in the same sample by their distinctive melting temperature (T(m)) which is 77.5°C for PPV VP2 313bp amplicon and 82.

Enhancing immune responses to inactivated porcine parvovirus oil emulsion vaccine by co-inoculating porcine transfer factor in mice.

Inactivated porcine parvovirus (PPV) vaccines are available commercially and widely used in the breeding herds. However, inactivated PPV vaccines have deficiencies in induction of specific cellular immune response. Transfer factor (TF) is a material that obtained from the leukocytes, and is a novel immune-stimulatory reagent that as a modulator of the immune system.

Inhibitory effects of indigowoad root polysaccharides on porcine reproductive and respiratory syndrome virus replication in vitro.

Background: Indigowoad root polysaccharide (IRPS) is a natural polysaccharide isolated from the traditional Chinese medicinal herb Radix Isatidis, and has many kinds of biological activities. However, the IRPS antiviral activity, especially the anti-porcine reproductive and respiratory syndrome virus (PRRSV) effect, has not been evaluated.

Methods: PRRSV was propagated in the MARC-145 cell line, and viral titre was determined by cytopathic effect and expressed as the 50% tissue culture infection dose (TCID(50)) in the current study.

Use of a Multiplex RT-PCR Assay for Simultaneous Detection of the North American Genotype Porcine Reproductive and Respiratory Syndrome Virus, Swine Influenza Virus and Japanese Encephalitis Virus.

A multiplex reverse transcriptase-polymerase chain reaction (multiplex RT-PCR) assay was developed and subsequently evaluated for its efficacy in the detection of multiple viral infections simultaneously, in swine. Specific primers for each of the 3 RNA viruses, North American genotype porcine reproductive and respiratory syndrome virus, Japanese encephalitis virus, and swine influenza virus, were used in the testing procedure. The assay was shown to be highly sensitive because it could detect as little as 10 ng of each of the respective amplicons in a single sample containing a composite of all 3 viruses.

Enhancement of the immunogenicity of an infectious laryngotracheitis virus DNA vaccine by a bicistronic plasmid encoding glycoprotein B and interleukin-18.

A DNA vaccine against infectious laryngotracheitis virus (ILTV) can induce specific humoral and cell-mediated immunity. However, compared to conventional vaccines, DNA vaccines usually induce poor antibody responses. To determine if co-expression of a cytokine can result in a more potent ILTV DNA vaccine, immunogenicity and protective efficacy of a monocistronic vector encoding the glycoprotein B (gB) of ILTV was compared to that of a bicistronic vector separately encoding the gB and chicken interleukin-18.

Cloning, in vitro expression, and bioactivity of interleukin-18 isolated from a domestic porcine breed found in Henan.

To evaluate the effects of recombinant porcine interleukin-18 (rpIL-18) on the replication of viruses in host cells and proliferation of lymphocytes, porcine IL-18 (pIL-18) isolated from a domestic big-white porcine breed found in the Henan province (HN) was cloned using a reverse transcriptase-PCR. The cloned HN pIL-18 contained an ORF of 579 base pairs encoding a 192-amino-acid precursor protein. The amino acid sequence of HN pIL-18 was compared with all the other pIL-18 amino acid sequences and varied by at least one amino acid to the consensus of all the others available.

Nitric oxide inhibits the replication cycle of porcine parvovirus in vitro.

This study investigated the inhibitory effect and mechanism of nitric oxide (NO) on porcine parvovirus (PPV) replication in PK-15 cells. The results showed that two NO-generating compounds, S-nitroso-L-acetylpenicillamine (SNAP) and L-arginine (LA), at a noncytotoxic concentration could reduce PPV replication in a dose-dependent manner and that this anti-PPV effect could be reversed by the NO synthase (NOS) inhibitor N-nitro-L-arginine methyl ester (L-NAME). By assaying the steps of the PPV life cycle, we also show that NO inhibits viral DNA and protein synthesis.

A TaqMan-based real-time polymerase chain reaction for the detection of porcine parvovirus.

A real-time polymerase chain reaction (PCR) using a TaqMan probe was developed to detect porcine parvovirus (PPV). Real-time PCR was optimized to quantify PPV using a detection system (Rotor Gene 2000 detector) and a dual-labeled fluorogenic probe. The gene-specific labeled fluorogenic probe for the VP2 gene of PPV was used to detect PPV.

Phenotypic and molecular characterization of TEM-116 extended-spectrum beta-lactamase produced by a Shigella flexneri clinical isolate from chickens.

Extended-spectrum beta-lactamases (ESBLs) produced by a clinical isolate of Shigella flexneri from chickens were detected with confirmatory phenotypic tests of the Clinical and Laboratory Standards Institute, and minimum inhibitory concentrations of several antibacterial drugs against the isolate were determined by the twofold dilution method. The genotype and subtype of the ESBL-producing S. flexneri isolate were identified by PCR amplifying of ESBL genes and DNA sequencing analysis.

[Prokaryotice expression of the NS1 gene of PPV and renaturation of the recombinant protein].

The antigen of NS1 gene of PPV was amplified by PCR, and the amplified fragments were cloned into the prokaryotic expression vector pGEX-4T-1. The insert position, the size and the frame were identified by PCR, restriction enzyme digestion and the sequence analysis of the recombinant plasmids. The sequence analysis results of pGEX-NS1-HN1 showed that the prokaryotic expression vector was successfully constructed.

[Construction of the eukaryotic expression vector with IL-2 gene and VP2 gene of PPV and research on immunogenicity].

To construct gene vaccine of PPV and to investigate the effects of interleukin 2 (IL-2) as an adjuvant on immune responses in mouse, the recombinant expression plasmid of pCIneo-IL2-VP2 was constructed and transfected into PK-15 cells by lipofectamine, the expressed product was detected by immunofluore assay. To study the immune effects of DNA vaccine in vitro and in vivo, mice were used as the animal model. The recombinant plasmid pCIneo-IL2-VP2, the control plasmid pCI-neo and the PPV live vaccine were immunized by intramuscular injection.