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Porcine hemagglutinating encephalomyelitis virus (PHEV), porcine pseudorabies virus (PRV), and classical swine fever virus (CSFV) are currently prevalent worldwide and cause similar neurological symptoms in infected pigs. It is very important to establish a detection method that can rapidly and accurately detect and differentiate these three viruses. Targeting the PHEV N gene, PRV gB gene, and CSFV 5′ untranslated region (5′UTR), three pairs of specific primers and probes were designed, and a triplex crystal digital reverse transcription-PCR (cdRT-PCR) was developed to detect PHEV, PRV, and CSFV. The results indicated that this assay had high sensitivity, and the limitation of detection (LODs) for PHEV, PRV, and CSFV were 4.812, 4.047, and 5.243 copies/reaction, respectively, which was about 50 times higher than that of multiplex real-time quantitative RT-PCR (RT-qPCR). This assay showed good specificity, without cross-reaction with other important swine pathogens, i.e., FMDV, PRRSV, PEDV, SIV, TGEV, PoRV, and PCV2. This assay had high repeatability, with intra-assay coefficients of variation (CVs) of 0.73–1.87%, and inter-assay CVs of 0.57–2.95%. The developed assay was used to test 1,367 clinical tissue samples from Guangxi province in China, and the positive rates of PHEV, PRV, and CSFV were 3.44% (47/1,367), 1.24% (17/1,367), and 1.90% (26/1,367), respectively, with a coincidence rate of 98.98% and a Kappa value of 0.94 to the reference multiplex RT-qPCR. The established triplex cdRT-PCR was a highly rapid, sensitive, and accurate assay to detect and differentiate PHEV, PRV, and CSFV. [ABSTRACT FROM AUTHOR]

The aim of this experiment was to investigate the regulatory effects of Spirulina platensis polysaccharide (PSP) on oxidative stress in spleen of mice infected with porcine pseudorabies virus (PRV). A total of 120 BALB/c mice were randomly divided into 5 groups, including high-dose PSP-1 (4 mg) group, medium-dose PSP-1 group (2 mg) group, low-dose PSP-1 group (1 mg) group, PRV group and blank control group. On the first day, the high, medium, and low-dose PSP-1 groups and the PRV group were intraperitoneally injected with PRV solution, while the blank control group was intraperitoneally injected with sterile physiological saline. Then, from day 1 to 6, the high, medium, and low-dose PSP-1 groups were orally administered with corresponding doses of PSP-1, while the PRV group and blank control group were orally administered with sterile physiological saline. On the 7th day, the mice were sacrificed. The contents of MDA and NO and the enzyme activities of SOD and iNOS in the mouse spleen were determined by assay kit method. H.E. staining was used to observe the pathological changes of spleen of the animals. The expression of HO-1 and iNOS in the mouse spleen was detected by immunohistochemistry. The findings indicated that the contents of MDA and NO and the activity of iNOS in spleen of mice in high dose PSP-1 group were significantly decreased when compared with PRV group (P<0.05), and the activity of SOD was significantly increased (P<0.05). H.E. staining showed that the pathological changes of spleen were alleviated to different degrees after treatment with different doses of PSP-1. Immunohistochemical results showed that the expression of HO-1 in spleen of PRV-infected mice increased in different doses of PSP-1, while the expression of iNOS decreased in different degrees. The results showed that PSP-1 can alleviate the spleen damage of PRV-infected mice and alleviate oxidative stress caused by PRV-infected mice. [ABSTRACT FROM AUTHOR]

Simple Summary: African swine fever virus (ASFV), porcine reproductive and respiratory syndrome virus (PRRSV), classical swine fever virus (CSFV), and porcine pseudorabies virus (PRV) are important pathogens circulating in pig herds in many countries. Pigs infected with these viruses show similar signs, such as increased body temperature and loss of appetite, and are prone to respiratory symptoms, digestive symptoms, neurological symptoms, and/or abortion in pregnant sows. To accurately detect these viruses and differentially diagnose these diseases, four pairs of specific primers and TaqMan probes were designed aiming at the B646L (p72) gene of ASFV, the 5′ untranslated region (5′UTR) of CSFV, the ORF6 gene of PRRSV, and the gB gene of PRV. After optimizing the reaction conditions, a multiplex real-time quantitative RT-PCR (RT-qPCR) assay was developed for the differential detection of ASFV, CSFV, PRRSV, and PRV. The assay was further validated to test 3116 clinical samples, and the positivity rates of ASFV, CSFV, PRRSV, and PRV were 10.84% (338/3116), 0.80% (25/3116), 14.92% (465/3116), and 1.38% (43/3116), respectively. The assay provides a highly specific, sensitive, and reproducible method for the detection of ASFV, CSFV, PRRSV, and PRV. African swine fever virus (ASFV), classical swine fever virus (CSFV), porcine reproductive and respiratory syndrome virus (PRRSV), and porcine pseudorabies virus (PRV) induce similar clinical signs in infected pigs, including hyperthermia, anorexia, hemorrhage, respiratory distress, neurological symptoms, and/or abortions in pregnant sows. The differential diagnosis of these diseases relies on laboratory examinations. In this study, a quadruplex RT-qPCR was established using four pairs of specific primers and probes aimed at the B646L (p72) gene of ASFV, the 5′ untranslated region (5′UTR) of CSFV, the ORF6 gene of PRRSV, and the gB gene of PRV for the detection and differentiation of ASFV, CSFV, PRRSV, and PRV. The assay exhibited great sensitivity with limits of detection (LODs) of 134.585, 139.831, 147.076, and 142.331 copies/reaction for ASFV, CSFV, PRRSV, and PRV, respectively. The assay exclusively identified ASFV, CSFV, PRRSV, and PRV, yielding negative results for the other control swine viruses used in this study. The intra-assay and inter-assay coefficients of variation (CVs) were not higher than 1.12%, indicating good reproducibility of the assay. The quadruplex RT-qPCR assay was used to analyze 3116 clinical tissue samples from pigs in Guangxi province, China, from April 2023 to September 2024. ASFV, CSFV, PRRSV, and PRV had positivity rates of 10.84% (338/3116), 0.80% (25/3116), 14.92% (465/3116), and 1.38% (43/3116), respectively, demonstrating a coincidence rate of ≥99.45% with the previously described RT-qPCR assays, which were also used to test these same samples. The established assay was rapid, sensitive, and accurate in detecting and differentiating ASFV, CSFV, PRRSV, and PRV. [ABSTRACT FROM AUTHOR]

Porcine hemagglutinating encephalomyelitis virus (PHEV), porcine pseudorabies virus (PRV), and classical swine fever virus (CSFV) are currently prevalent worldwide and cause similar neurological symptoms in infected pigs. It is very important to establish a detection method that can rapidly and accurately detect and differentiate these three viruses. Targeting the PHEV N gene, PRV gB gene, and CSFV 5′ untranslated region (5′UTR), three pairs of specific primers and probes were designed, and a triplex crystal digital reverse transcription-PCR (cdRT-PCR) was developed to detect PHEV, PRV, and CSFV. The results indicated that this assay had high sensitivity, and the limitation of detection (LODs) for PHEV, PRV, and CSFV were 4.812, 4.047, and 5.243 copies/reaction, respectively, which was about 50 times higher than that of multiplex real-time quantitative RT-PCR (RT-qPCR). This assay showed good specificity, without cross-reaction with other important swine pathogens, i.e., FMDV, PRRSV, PEDV, SIV, TGEV, PoRV, and PCV2. This assay had high repeatability, with intra-assay coefficients of variation (CVs) of 0.73–1.87%, and inter-assay CVs of 0.57–2.95%. The developed assay was used to test 1,367 clinical tissue samples from Guangxi province in China, and the positive rates of PHEV, PRV, and CSFV were 3.44% (47/1,367), 1.24% (17/1,367), and 1.90% (26/1,367), respectively, with a coincidence rate of 98.98% and a Kappa value of 0.94 to the reference multiplex RT-qPCR. The established triplex cdRT-PCR was a highly rapid, sensitive, and accurate assay to detect and differentiate PHEV, PRV, and CSFV.

Porcine hemagglutinating encephalomyelitis virus (PHEV), porcine pseudorabies virus (PRV), classical swine fever virus (CSFV), and Japanese encephalitis virus (JEV) cause similar neurological symptoms in the infected pigs, and their differential diagnosis depends on laboratory testing. Four pairs of specific primers and probes were designed targeting the PHEV N gene, PRV gB gene, CSFV 5′ untranslated region (5’UTR), and JEV NS1 gene, respectively, and a quadruplex real-time quantitative RT-PCR (qRT-PCR) was developed to detect and differentiate PHEV, PRV, CSFV, and JEV. The assay showed high sensitivity, with the limit of detection (LOD) of 1.5 × 101 copies/μL for each pathogen. The assay specifically detected only PHEV, PRV, CSFV, and JEV, without cross-reaction with other swine viruses. The coefficients of variation (CVs) of the intra-assay and the inter-assay were less than 1.84%, with great repeatability. A total of 1,977 clinical samples, including tissue samples, and whole blood samples collected from Guangxi province in China, were tested by the developed quadruplex qRT-PCR, and the positivity rates of PHEV, PRV, CSFV, and JEV were 1.57% (31/1,977), 0.35% (7/1,977), 1.06% (21/1,977), and 0.10% (2/1,977), respectively. These 1,977 samples were also tested by the previously reported qRT-PCR assays, and the coincidence rates of these methods were more than 99.90%. The developed assay is demonstrated to be rapid, sensitive, and accurate for detection and differentiation of PHEV, PRV, CSFV, and JEV.