Porcine epidemic diarrhea virus (PEDV) is a highly contagious coronavirus that induces diarrhea and death in neonatal piglets, resulting in substantial economic losses to the global swine industry. The mechanisms of PEDV infection and the roles of host factors are still under exploration. In this study, we used the ferroptosis pathway downstream target activator (1S,3R)-RSL3 compound as a starting point, combined with the interactions of N-acetylcysteine and deferoxamine, to elucidate the effects of a series of compounds on PEDV proliferation. We also established glutathione peroxidase 4 (GPX4) gene overexpression to further elucidate the relationship between the ferroptosis pathway and PEDV. (1S,3R)-RSL3 inhibited PEDV replication in Vero cells, while N-acetylcysteine and deferoxamine promoted its proliferation. In addition, (1S,3R)-RSL3 mainly affected the replication stage of PEDV. Overexpression of GPX4 promoted PEDV proliferation, indicating that the ferroptosis pathway could influence PEDV replication in Vero cells. This study focused on the mechanism of (1S,3R)-RSL3 inhibition on PEDV, laying the foundation for exploring the pathogenic mechanisms of PEDV and drug development.

Rabies is a zoonotic viral disease that causes encephalitis in humans and other mammals, such as dogs, bats, raccoons and foxes (1). This disease generally includes two clinical forms, namely furious rabies and paralytic rabies (2). The former is characterized by hyperactivity and hallucinations; the latter is characterized by paralysis and coma. Rabies induces progressive and fatal inflammation of the brain and spinal cord. Once its clinical sign begins, the mortality rate is virtually 100% in humans. Rabies is still a serious public problem in over 150 countries and territories, mainly in Asia and Africa (3).The etiological agent of rabies is rabies virus (RV), a typical neurotropic virus. Its transmission is commonly through saliva, bites, scratches, or direct contact with mucosa (4).According to the latest taxonomic classification, RV has been renamed lyssavirus rabies, classified into the genus Lyssavirus in the family Rhabdoviridae. The virion is a bullet-shaped particle with envelope, containing a single-stranded, negative-sense RNA genome, approximately 11.9 nt in length, encoding five proteins in order: nucleoprotein (N), phosphoprotein (P), matrix protein (M), glycoprotein (G), and RNA-dependent RNA polymerase (RdRp or L protein).The RV genome can be readily modified to accommodate a foreign antigen sequence for rescuing a recombinant virus using revere genetics (5). The recombinant, if demonstrated to be able to induce specific immune responses in vivo, would play a potential role in developing the RV-vectored vaccine. To date, there have been three types of RV-vectored vaccines: live-attenuated, inactivated and replication-deficient patterns. They showed their individual strengths and weaknesses, both of which were critically discussed here.The reverse genetics platform of RV was initially reported in 1994 (6), subsequently revolutionizing the researches on RV and even on other RNA viruses. This reverse genetics platform includes four plasmids, and one cell line. The four-plasmid system contains one viral cDNA clone, and three helper plasmids that separately express N, P and L proteins. An RV-vectored cDNA clone generally possesses an extra transcriptional unit of foreign antigen.Recovery of RV involves co-transfection of these four plasmids into a cell line [for a review on the protocol, see (5)]. The rescued chimeric RV will be characterized for verifying its ability in the expression of foreign antigen in vitro, and then subjected to the animal test for unveiling its potential in eliciting specific immune responses. Table 1 The requirements for developing live-attenuated RV-vectored vaccines (LRVs) include many basic features: no or low virulence in hosts, ability of reaching high-level titers via cell culture, continuously eliciting cellular and humoral immune responses, thermal stability, and last but not least, genetic stability of foreign sequence. LRVs are factually the replication-competent RVs, able to replicate continuously in animals. They usually require fewer doses, and moreover provide more long-lasting protection than inactivated vaccines. A single-dose vaccination schedule is enough to induce high titers of specific antibodies in vivo (27). Moreover, LRVs offer more comprehensive and long-lasting protection in animals from pathogens.Besides the humoral immunity, the LRVs also induce cellular immunity, because viable RVs propagate in host's cells and express endogenous antigens for further processing and presentation.The cell-mediated immune response is crucial for eliminating pathogens inside the host's cells. against RV G protein and SHIV 89.6P Env was detectable after the initial immunization, whereas the cell-mediated immune response was not identified against the SHIV antigens (36).Although LRVs have been widely demonstrated to be powerful in eliciting protective immune responses in animals, there are still two weaknesses that should not be neglected for the development of LRVs. The first one is the potential risk in reversion to virulence. Most RNA viruses are genetically unstable during genomic replication, due to the low-fidelity characteristics of their RdRps (38). RVs have been rapidly evolving (39), and been even recombining with one another (40). A single mutation of amino acid in its G protein will quicken its spread, and even intensify its pathogenicity (41)(42). Therefore, the potential reversion to virulence hampers the further application of LRVs. The other weakness, albeit rarely reported as yet, should not also be neglected to design an LRV. This weakness is that a foreign sequence is possibly unstable in a chimeric RV genome, since the foreign sequence is theoretically uninvolved in virus-associated events. If a certain foreign sequence is deleted from a chimeric RV genome, the resultant RV would be still a replication-competent strain, but lose its own primary properties of vector vaccine.The inactivated RV-vectored vaccine (IRV) is produced as a killed version of antigen-expressing RV. The prerequisite for developing a certain IRV is that a target antigen must be incorporated into the envelope of chimeric RV virion (43). Some viral glycoproteins, if expressed through the RV vector in cells, can be further processed, modified and finally transported to the cell surface. These viral glycoproteins, as membrane-spanning proteins, will be embedded into the cell envelope. Along with the viral budding, the foreign antigen can be incorporated into the envelope of RV virion. Many viral glycoproteins, like those of Lassa virus (20) and Ebola virus (12), were reported to have such a feature, therefore playing a potential role in the development of the IRVs.However, not all viral glycoproteins can be directly used as a complete foreign antigen for preparing the IRV. Some ones need to be modified for the incorporation into RV virions. For instance, Rift Valley fever virus (RVFV) morphogenesis is by means of budding from the Golgi complex. In...

RNA recombination: non-negligible factor for preventing emergence or reemergence of Senecavirus A

Salmonella is a major foodborne pathogen, yet real-time data on duck-derived strains in China remain scarce. This study investigated the epidemiology, antimicrobial resistance (AMR), gene profiles, and PFGE patterns of 114 Salmonella isolates recovered from 397 deceased ducks (2021–2024) across nine provinces (isolation rate: 28.72%). Fourteen serotypes were identified, with S. Typhimurium (23.68%), S. Indiana (21.93%), S. Kentucky (18.42%), and S. Enteritidis (12.28%) being predominant. Most isolates showed high resistance to β-lactams, tetracyclines, quinolones, and sulfonamides, with extensive multidrug resistance (MDR) observed—especially in S. Indiana, S. Typhimurium, and S. Kentucky. Among the 23 detected resistance genes, tet(B) had the highest prevalence (75.44%), particularly in S. Indiana. Biofilm formation was observed in 99.12% of isolates, with 84.21% demonstrating moderate to strong capacity. Eighteen virulence genes were detected; S. Enteritidis carried more spvB/C, sipB, and sodC1, while S. Indiana had higher cdtB carriage. PFGE revealed substantial genetic diversity among strains. This comprehensive analysis highlights the high AMR and biofilm potential of duck-derived Salmonella in China, emphasizing the urgent need for enhanced surveillance and control measures to mitigate public health risks.