Porcine reproductive and respiratory syndrome (PRRS) is one of the most important diseases that has brought significant economic losses to the swine industry worldwide. Rapid and accurate PRRS virus (PRRSV) detection is one of the key factors for PRRS prevention and control. This study developed a real-time fluorescence-based reverse transcription recombinase-aided amplification (RF-RT-RAA) method for type 2 PRRSV (PRRSV-2) detection. The RF-RT-RAA assay could be performed at 42 °C for 20 min with the optimal primers and a probe. RF-RT-RAA results could be monitored using real-time fluorescence read-out or visually observed with the naked eye using a portable blue light transilluminator. The method had a strong specificity; no cross-reaction was identified with the detected common swine viruses. Moreover, the technique yielded high sensitivity with the lowest detection limit of 10¹ copies/μL and exhibited good repeatability and reproductively with the coefficients of variation (CV) less than 10%. Eighty-seven clinical samples were tested using RF-RT-RAA and a commercial PRRSV-2 RT-qPCR detection kit. The coincidence rate was 100% between RF-RT-RAA (real-time fluorescence read-out) and RT-qPCR, and 97.7% between RF-RT-RAA (visually observed) and RT-qPCR. The RF-RT-RAA assay provides a new method for rapid and visual detection of PRRSV-2.

African swine fever (ASF) is one of the most severe diseases caused by the ASF virus (ASFV), causing massive economic losses to the global pig industry. Serological tests are important in ASF epidemiological surveillance, and more antigen targets are needed to meet market demand for ASFV antibody detection. In the present study, ASFV p15 protein was fusion-expressed in Escherichia coli (E. coli) with elastin-like polypeptide (ELP), and the ELP-p15 protein was purified using a simple inverse transition cycling (ITC) process. The ELP tag was cleaved off using tobacco etch virus protease (TEVp), resulting in a tag-free p15 protein. Western blot analysis demonstrated that the p15 protein reacted strongly with ASFV-positive serum. The p15 protein was used as a coating antigen in an indirect ELISA (iELISA) for detecting ASFV antibodies. The p15-iELISA method demonstrated high specificity to ASFV-positive sera, with a maximum detection dilution of 1:1600. Moreover, the method exhibited good reproducibility, with less intra-assay and inter-assay CV values than 10%. Therefore, p15-iELISA offers a novel approach for accurately detecting ASFV antibodies with significant clinical application potential.

Liver disease is a serious threat to health worldwide. Flavonoids from Suaeda glauca (SGF) is able to alleviate liver lipid peroxidation. However, it is unclear whether SGF could protect against liver glycogen accumulation, inflammation and fibrosis. In this study, the extraction conditions of SGF were optimized with response surface methodology. The qualitative analysis of components in SGF was carried out by a LC-MS/MS method. Moreover, SGF was administered orally to male mice given 10 % carbon tetrachloride (CCl₄) for 4 weeks at doses of 25 and 50 mg/kg once daily for 4 weeks. The optimal extraction conditions of SGF were as follows: the ratio of material to liquid 1:35, the temperature 67 °C, the time 3 h, and the ethanol concentration 89 %. Thirty-five compounds were preliminarily identified in SGF. Furthermore, SGF could significantly improve liver dysfunction, regulate the hepatic protein levels of glucose-6-phosphatase, glycogen synthase, glycogen phosphorylase L, Laforin, interleukin-1β, gasdermin-D, NOD-like receptor (NLR) family, pyrin domain containing 3 inflammasome, α-smooth muscle actin, the hepatic mRNA levels and enzyme activities of matrix metallopeptidase 9, tissue inhibitor of metalloproteinases 1, and collagen 1α1, reduce the liver glycogen accumulation, inflammation and fibrosis in mice induced by CCl₄. These results indicated that SGF may be a promising drug for the treatment of liver injury.