Foot-and-mouth disease virus (FMDV) causes a severe vesicular disease in domestic and wild cloven-hoofed animals. Because of the limited early protection induced by current vaccines, emergency antiviral strategies to control the rapid spread of FMD outbreaks are needed.

Introduction: Senecavirus A (SVA), an emerging vesicular pathogen, is responsible for porcine idiopathic vesicular disease (PIVD). This disease is closely associated with porcine vesicular disease and acute neonatal piglet mortality, presenting a substantial threat to the global swine industry. At present, the absence of effective drugs or vaccines for treating the disease makes accurate diagnosis of SVA of paramount importance for the effective prevention and control of the disease.Methods: In this study, we combined reverse transcription loop-mediated isothermal amplification (RT-LAMP) and Clustered Regularly Interspaced Short Palindromic Repeats and CRISPR-associated protein12a (CRISPR/Cas12a) using a dual-labelled fluorescence quencher or fluorescent biotin single-stranded DNA reporter molecule to develop two rapid, reliable, and portable visual SVA assays: RT-LAMP-Cas12a-FQ and RT-LAMP-Cas12a-FB.Results: The two methods exhibited comparable detection limits, with 9.6 copies/μL achieved in 40 and 45 minutes, respectively. They did not cross-react with non-target nucleic acids extracted from other related viruses and showed high specificity for SVA RNA detection. Furthermore, the methods demonstrated satisfactory performance in detecting 69 porcine adventitious samples, with no significant differences from that of quantitative reverse transcription polymerase chain reaction (RT-qPCR).Discussion: In summary, the RT-LAMP-Cas12a-FQ and RT-LAMP-Cas12a-FB methods developed are promising for early detection and routine surveillance of porcine SVA in resource-poor areas.

Foot-and-mouth disease (FMD) is an infectious disease in animals caused by the foot-and-mouth disease virus (FMDV). However, the mechanism of FMDV infection in host cells remains unclear. In this study, we utilized ¹²C⁶ heavy ion irradiation technology to process BHK-21 cells and systematically screened and evaluated cell lines with distinct virus replication characteristics. We subsequently employed proteomics to detect the differences between these cell lines and the control BHK-21 cell line following ¹²C⁶ heavy ion irradiation. Both cell lines exhibited common downregulation of cell adhesion molecules but also exhibited distinct upregulation pathways. In terms of immune and metabolic responses, BHK-5 infection triggered an immune response, including the upregulation of cytokine–cytokine receptor signaling pathways and lysosome-related pathways, while the upregulation of drug metabolism pathways enhanced the ability to metabolize exogenous substances. Conversely, BHK-7 infection tended to promote metabolic pathway changes that favor virus replication, such as the upregulation of folate biosynthesis, polysaccharide degradation, and linolenic acid metabolism pathways. Additionally, we observed significant downregulation of Cbr3 in cell lines that promoted virus replication and significant upregulation in those that inhibited virus replication. Upon validating the results in Cbr3 knockout cells, we found that knocking out Cbr3 could increase FMDV replication by increasing the cellular content of prostaglandin E2 (PGE2), suggesting a close relationship between FMDV replication and PGE2 levels. This method can increase the production efficiency of FMDV vaccines while reducing manufacturing costs. This study innovatively employed ¹²C⁶ heavy ion irradiation technology to induce cell transformation and explored its impact on FMDV, offering a new perspective for understanding virus replication mechanisms and potentially providing a target and idea for developing novel antiviral strategies.

African swine fever virus (ASFV) is a highly pathogenic agent that poses a severe threat to the global swine industry. The biological function of A859L, an ASFV-encoded RNA helicase, remains largely elusive. Here, we show that A859L is highly conserved across diverse ASFV isolates and belongs to the SF2 superfamily of RNA helicases, possessing characteristic Walker A (GKT) and Walker B (DECH) motifs. Transcriptomic profiling at multiple time points post-infection further revealed that A859L is a late-expressed gene. Functional assays demonstrated that siRNA-mediated knockdown of A859L significantly inhibited progeny virus production in both susceptible macrophages (PAMs and BMDMs) and WSL cells. This knockdown also markedly reduced the expression of viral proteins p30 and p72, as well as the intracellular mRNA levels of other viral helicase genes (QP509L, Q706L, D1133L, and B962L), underscoring the vital role of A859L in the viral life cycle. Conversely, A859L overexpression enhanced viral propagation. Notably, pharmacological inhibition of viral helicase activity effectively suppressed ASFV replication. Collectively, our data establish A859L as a critical determinant of ASFV replication and a promising candidate for antiviral development.