Flavonoids are one of the most essential compounds in various plants. This study used the cellulase-assisted method to extract flavonoid-enriched antioxidants from Equisetum arvense L. (EAL). According to a three-factor and three-level central composite design, the response surface methodology was used to obtain the maximum total flavonoid yield, thereby providing the most potent antioxidant activity of EAL extracts. The results indicated that the optimal condition for the total flavonoid extraction was 0.52% (base substrate) enzyme concentration and enzymolysis for 50.58 min at 49.03 °C. The extraction rate of flavonoids from horsetail reached 4.88 mg/g under these optimal conditions. The yield was 51.23% higher than that from the traditional solid–liquid extraction method. The highest DPPH-scavenging ability of the extracts obtained under 0.50% enzyme concentration and enzymolysis for 49.41 min at 46.59 °C was 77.36%. HPLC results revealed that the antioxidant substances had diverse flavonoids. Thus, the extraction condition was consistent for antioxidant activity and total flavonoids. Therefore, the current study provided an efficient method to extract flavonoid compounds from EAL, facilitating technical support for utilizing the plant.

Canine brucellosis, a worldwide zoonotic disease, is mainly caused by Brucella canis. In the present study, we isolated a Brucella strain (CD3) from a subclinically infected pet dog in Sichuan Province, Southwestern China. Classical biotyping methods and molecular biological tests (BCSP31 and BcSS PCR) proved that the strain belonged to B. canis. Furthermore, B. canis CD3 and another two B. canis strains (WJ5 and YA4), which were all isolated from pet dogs in Sichuan, were genotyped using multilocus sequence typing (MLST). Our results showed that the three B. canis strains were identified as the same sequence type (ST21). The present study is the first to report B. canis strain from a subclinically infected pet dog in China, indicating a potential threat to public health posed by subclinical infections in pet dogs. We suggest that screening for B. canis should be incorporated into routine medical examination of pet dogs and other companion animals in areas with a history of animal or human brucellosis.

Porcine circovirus type 3 (PCV3) is a recently identified member of the porcine circovirus family, primarily associated with conditions such as dermatitis and nephropathy syndrome, reproductive failure, and multisystem inflammatory lesions in swine. There has been a significant increase in the prevalence of PCV3 in China, attracting considerable attention. Consequently, there is an urgent need for a highly sensitive, cost-effective, and efficient method for the detection of clinical samples. This study developed a TaqMan-based quantitative real-time PCR (TaqMan-qPCR) assay utilizing specific probes and primers designed based on the PCV3-REP gene. Following the optimization of reaction conditions, sensitivity analysis determined that the detection limit of this method was 7.3 × 10⁰ copies/µL. Specificity analysis demonstrated no cross-reactivity with other common porcine pathogens, underscoring its specificity. Furthermore, the inter- and intra-assay coefficients of variation were both less than 1%, indicating high reproducibility. A total of 2,454 clinical samples were collected and analyzed using the developed method. The findings revealed that the prevalence of PCV3 was highest in testicular fluid samples, with a rate of 71.28% and the lowest detected Cq values among all sample types, indicating a significant likelihood of vertical transmission of PCV3. Additionally, oral fluid samples exhibited the second highest positive rate at 59.83%, highlighting the importance of monitoring infection rates in fattening pig herds from a veterinary perspective. In conclusion, this study successfully developed a highly sensitive and specific TaqMan-qPCR method, which is effective for detecting PCV3 across a variety of clinical samples.

Porcine proliferative enteropathy (PPE) is an infectious disease in pigs, caused by Lawsonia intracellularis (LI), affecting their intestines during growth and finishing stages, leading to higher production costs. Current detection methods for LI face two main challenges, delayed results and high costs, making them impractical for large-scale pig farming epidemiological surveys. This study developed a TaqMan-qPCR method using specific probes and primers based on the LI aspartate ammonia lyase genes from GenBank, completing detection in just 45 min. After optimizing reaction conditions, sensitivity analysis revealed that the detection limit of this method was 4.6 copies/μL targeting standard plasmids. The results of the specificity analysis showed no cross-reactivity with other common porcine pathogens, highlighting its specificity. The inter- and intra-group coefficients of variation were both <1%, indicating high reproducibility. Furthermore, the TaqMan-qPCR demonstrated 100% relative sensitivity, and a 92.50% compliance rate compared to conventional PCR, suggesting it could be a complement to the conventional PCR method. In summary, the TaqMan-qPCR method established in this study is not only suitable for epidemiological investigations and early qualitative and quantitative diagnosis of proliferative enteropathy in pigs, but it is also valuable for studying the biological characteristics of LI.

Viral diseases that cause swine reproductive disorders pose severe threats to the global pig industry and result in enormous economic losses worldwide. The high similarity of clinical symptoms, widespread co-infections, and continuous emergence of novel pathogens urgently require rapid and accurate diagnostic strategies to support efficient disease prevention and control. This narrative review summarizes and analyzes the latest advances in diagnostic technologies for major swine reproductive viral pathogens, including Porcine Reproductive and Respiratory Syndrome Virus (PRRSV), Classical Swine Fever Virus (CSFV), Porcine Circovirus (PCV), Pseudorabies Virus (PRV), and Porcine Parvovirus (PPV). We mainly focus on state-of-the-art diagnostic approaches centered on nucleic acid detection and serological identification. In terms of nucleic acid detection, this review elaborates on the technological evolution from conventional Polymerase Chain Reaction (PCR) to real-time quantitative PCR (qPCR) and digital PCR (dPCR), highlighting the critical value of multiplex PCR (mPCR) in differential diagnosis of swine viral diseases. Meanwhile, we summarize widely applicable isothermal amplification techniques, including Loop-Mediated Isothermal Amplification (LAMP) and Recombinase Polymerase Amplification (RPA)/Recombinase-Aided Amplification (RAA), which are highly suitable for point-of-care testing (POCT). Emerging CRISPR-Cas-based diagnostic systems for swine viral detection are also comprehensively discussed. Regarding serological detection, this article systematically reviews diverse Enzyme-Linked Immunosorbent Assay (ELISA) methods and their practical applications in serological antibody monitoring and the Differentiating Infected from Vaccinated Animals (DIVA) strategy. Furthermore, the potential application of Lateral Flow Immunoassay (LFIA) in rapid on-site screening is evaluated. This review aims to provide a comprehensive and up-to-date theoretical reference for the precise prevention and targeted control of swine reproductive viral diseases.

Avian influenza virus (AIV), a zoonotic pathogen capable of cross-species transmission, poses a significant global health threat due to its rapid evolutionary adaptation. This review consolidates evidence from the past decade on AIV-autophagy interactions, emphasizing mechanistic insights and therapeutic potential. Research indicates that various AIV strains can trigger autophagosome formation via viral components, although the completeness of autophagic flux is not fully understood. These virus–host interactions are notably influenced by viral genotypes (e.g., H5N1 vs. H9N2) and host species (avian vs. mammalian). Current studies suggest that modulating autophagy may reduce AIV-induced acute lung injury, with pharmacological agents showing potential in mitigating inflammatory responses. We systematically explore three research areas: (1) strain-specific mechanisms of autophagy induction, (2) host-specific autophagic responses in poultry and human models, and (3) the therapeutic potential of stage-specific autophagy manipulation. This synthesis clarifies critical knowledge gaps, particularly the need for standardized autophagic flux assessment in avian cells, while providing a conceptual framework for developing autophagy-targeted strategies against AIV pathogenesis.