T. gondii is a globally prevalent intracellular parasite that poses significant public health challenges. However, its virulence mechanisms remain poorly understood. Here, we identified cleft lip and palate transmembrane protein 1 (CLPTM1, TGME49_205240) as a critical virulence factor and systematically characterized its role. The CLPTM1 deletion strain (Δclptm1) grows normally in vitro but completely loses virulence in vivo, with 100% survival of infected mice and no brain cyst formation. Serum IL-6 levels and tissue pathology in major organs were significantly reduced in Δclptm1-infected mice, indicating attenuated systemic inflammation and tissue damage. Transcriptomic analysis revealed that Δclptm1 infection markedly downregulated key chemokine genes (CCL5, CCR7 and CCL22) in macrophages. This trend was further supported by the reduced expression of these chemokines and decreased F4/80⁺ macrophage infiltration in liver and lung tissues. Concomitantly, diminished phosphorylation of IκB-α, along with decreased levels of p65 and its activated form pp65, suggests that CLPTM1 promotes chemokine expression by facilitating the activation of the NF-κB signaling pathway. Consistently, pp65 expression in liver and lung tissues was markedly reduced in the Δclptm1-infected group. Here, we delineate a mechanistic axis whereby CLPTM1 influences T. gondii virulence through the activation of the host NF-κB/chemokine/macrophage pathway, thereby promoting inflammation and immune cell infiltration. This study provides new insight into T. gondii pathogenesis and lays a foundation for the future development of diagnostic, therapeutic, and vaccine strategies against toxoplasmosis.

Lumpy skin disease (LSD), a highly contagious viral infection caused by Lumpy Skin Disease Virus (LSDV), has caused severe economic losses. We analyzed three representative outbreaks in 2024, combining clinical, histopathological, serological, and molecular data to refine regional control strategies. According to our findings, affected cattle presented with generalized cutaneous nodules, fever and peripheral edema; one-third of in-contact animals remained clinically normal yet seroconverted within ten days. Antibody titers peaked at approximately 20 d post-onset and were accompanied by persistent viral DNA in saliva, ocular secretions and skin scabs. Histology revealed alveolar septal edema, hepatocellular ballooning, and glomerular necrosis, whereas biochemical profiling revealed hypalbuminemia, hyperglobulinemia, and elevated alanine aminotransferase in one patient. Immunohistochemistry revealed intense LSDV antigen in the spleen, alveolar septa of the lung, and throughout the dermis of the skin nodules, identifying these tissues as the most reliable diagnostic targets. The combined findings confirm active viral replication in cutaneous, respiratory and lymphoid tissues, highlight the occurrence of subclinical infection and underscore the value of paired serology and PCR for herd screening. Prompt isolation, vector control and vaccination with homologous capripox vaccines are recommended to curtail transmission and economic impact.

African swine fever (ASF), caused by African swine fever virus (ASFV), is a devastating disease of domestic pigs with mortality rates approaching 100%, leading to severe global economic losses. No effective vaccines or antivirals are available, highlighting the urgent need for novel therapeutic strategies and efficient screening tools. We developed a recombinant ASFV-expressing dual reporter (mCherry and NanoLuc), rASFV_mChNluc, and established a high-content screening (HCS) platform optimized for cost-effective, low-labor analysis via the mCherry reporter. The assay demonstrated excellent robustness (Z′-factor = 0.669±0.064) and successfully verified the activity of the known ASFV inhibitor AraC, confirming inhibition at the postinfection stage. Screening of an in-house fungal extract library (493 extracts) identified 25 hits (5.07%) that reduced viral infectivity to < 5%. Extracts from the insect fungi Beauveria neobassiana and Samsoniella aurantia showed potent activity, with an SI > 62.81 (EC₅₀ = 1.99±0.71 µg/mL) and an SI > 42.92 (EC₅₀ = 11.65±2.99 µg/mL), respectively. Time-of-addition assays indicated that B. neobassiana acts at multiple replication stages, whereas S. aurantia targets the postinfection stage. This study establishes a robust ASFV HCS platform for efficient high-throughput antiviral discovery and highlights fungi as a promising source of novel ASFV inhibitors.

Nipah virus disease, caused by Nipah virus (NiV), is a zoonotic infectious disease with an extremely high fatality rate. Owing to the absence of effective countermeasures, Nipah virus disease has caused substantial economic losses in the swine farming industry. Vaccines represent the most cost-effective approach for prevention and control. Herein, we describe the development of a recombinant pseudorabies virus (PRV)-vectored vaccine (designated PRV-HNX-ΔTK/gE-NiV-G), which expresses the codon-optimized full-length glycoprotein of Nipah virus (NiV-G). The biological characteristics of this strain, including plaque morphology, growth kinetics, and genetic stability, were evaluated in vitro. Furthermore, the recombinant virus exhibited favorable safety profiles in mice. Intramuscular administration of PRV-HNX-ΔTK/gE-NiV-G elicited high-titer neutralizing antibodies against NiV-G and a robust cellular immune response in BALB/c mice. Taken together, these findings indicate that PRV-HNX-ΔTK/gE-NiV-G has potential as a promising candidate for the development of bivalent vaccines that target both NiV and PRV infections.

Feline panleukopenia virus (FPV) is a highly contagious parvovirus that causes acute gastroenteritis, leukopenia, and high mortality in felids. Although domestic cats are commonly vaccinated, FPV continues to threaten captive and wild felids because of its environmental stability, rapid progression, and potential antigenic drift. In June 2022, a one-year-old captive female cougar (Puma concolor) at Hongshan Forest Zoo, Nanjing, China, was found dead following a peracute course without prodromal signs. The animal had previously received a trivalent feline vaccine containing feline panleukopenia, herpesvirus, and calicivirus antigens. Postmortem examination revealed perianal fecal staining, oral discharge, pulmonary congestion with peripheral emphysema, a darkened liver, and intestinal mucosal sloughing with petechiae. Histopathology revealed crypt epithelial necrosis, mucosal sloughing, and lymphoid depletion, which was consistent with parvoviral enteritis. Fecal and intestinal samples tested positive for FPV according to the lateral-flow assay and PCR. Viral replication was confirmed in CRFK cells via indirect immunofluorescence, and FPV antigen was shown to be localized to the intestinal crypt epithelium via immunohistochemistry. VP2 gene sequencing (1,753 bp) revealed that the isolate clustered with field strains from domestic cats in Jiangsu and Shanghai, which share near-complete nucleotide identity but differ from the Felocell vaccine strain in three amino acid substitutions (A91S, I232V, and L562V), two of which lie in antigenic loops and may affect antigenicity. No further FPV cases were detected during or after the 14-day observation period, reflecting successful containment through disinfection, relocation, feral cat control, and movement restrictions. This represents the first confirmed fatal FPV infection in a captive cougar in China and highlights the potential for local spillover from domestic reservoirs. The case underscores the need for continuous molecular surveillance, vaccination evaluation, and One Health–based biosecurity to protect susceptible wildlife populations at the human–domestic–wildlife interface.

Porcine reproductive and respiratory syndrome virus 1 (PRRSV-1) has emerged as a critical pathogen that threatens swine herds across China. In this study, a novel PRRSV-1 strain, designated XJEU2308, was isolated from a PRRSV outbreak in a previously confirmed PRRSV-negative (both RNA and antibody negative) swine herd in Xinjiang, China. During the outbreak surveillance period, production records revealed a mean stillbirth rate of 12.19% and a suckling piglet mortality rate of 56.07%. Phylogenetic analysis on the basis of the ORF5 gene classified XJEU2308 as a BJEU06-1-like strain, whereas whole-genome analysis clustered it within the newly identified "New subgroup 1" of Chinese PRRSV-1. Notably, this strain carried a unique 3-amino acid deletion (at positions 693–695) in nonstructural protein 2 (NSP2). In challenge experiments, XJEU2308 induced typical clinical symptoms and exhibited moderate pathogenicity. Importantly, the implementation of the load-close-exposure (LCE) strategy combined with field virus (FLV) exposure successfully restored the herd to a provisional PRRSV-negative status. Overall, this study isolated a new subgroup 1-like PRRSV-1 strain from a swine farm that experienced a reproductive failure outbreak; the strain is characterized by a unique 3-amino-acid deletion in the NSP2 gene and moderate pathogenicity. Additionally, this study validated the effectiveness of the LCE-FLV strategy for containing PRRSV-1.