Search Results (497)

Salmonella is a globally important pathogen and one of the World Health Organization and One Health priority organisms. Reptiles represent environmental reservoirs of Salmonella serovars that can cause reptile-associated salmonellosis (RAS) in humans. Due to distinct biochemical features and uncommon O and H antigen variants, reptile-associated isolates may be difficult to identify using standard microbiological diagnostics. This study analyzed 62 Salmonella isolates obtained from wild and kept snakes in Poland. Samples originated from Natrix natrix, N. tessellata, Coronella austriaca, Zamenis longissimus, Elaphe dione and Nerodia fasciata species. Serovar prediction using SeqSero1.2 was compared with classical slide agglutination. Seventeen serovars were confirmed, with S. enterica subsp. diarizonae (IIIb) 38:r:z being the most frequent. For seven isolates, molecular and serological results were inconsistent. Among three isolates from Coronella austriaca predicted as IIIb 38:z₁₀:z₅₀, three distinct second-phase flagellar phenotypes were detected. Slide agglutination confirmed the presence of serovar 38:z₁₀:z₆, which has not been previously listed in the White–Kauffmann–Le Minor scheme or described in the scientific literature. The findings highlight the utility of genetic serovar prediction while emphasizing the need for continuous validation, particularly for the identification of rare or atypical Salmonella serovars associated with reptiles. Full article

To investigate the molecular characteristics of H3N2 canine influenza viruses circulating in Jiangsu, China, we isolated a H3N2 strain (A/Canine/Nanjing/CnNj01-2025) from a dog presenting with respiratory signs at the Veterinary Teaching Hospital of Nanjing Agricultural University. All eight gene segments were sequenced and compared with those of two human H3N2 strains and five avian H3N2 strains. Antigenicity and receptor-binding properties were also assessed. Phylogenetic analysis revealed that the canine isolate descended from the avian lineage and formed an independent evolutionary clade, while the human strains were more distantly related to the avian lineage. Glycosylation analysis of the HA protein revealed that the canine strain carried seven N-glycosylation sites, including a unique site at residue 97/81 (HA/H3 numbering), which serves as a molecular signature of the canine strain. Several amino-acid substitutions were identified in major antigenic sites, including D97/81N, A176/160T, N204/188D, V212/196I, and W237/222L. Analysis of internal genes showed that the canine strain harbored PB2 292T and 590S mammalian adaptation mutations, which are also present in human strains. Hemagglutination inhibition (HI) assays of the canine strain indicated moderate serologic cross-reactivity with a human H3N2 antiserum (16-fold reduction), whereas avian strains showed no cross-reactivity. Receptor-binding assays demonstrated that the virus retained predominant α-2,3 sialic acid binding, comparable to that of avian influenza viruses, and gained a modest affinity for human-type α-2,6 sialic acid receptors. Therefore, the canine H3N2 virus has undergone significant antigenic drift, developed partial serological cross-reactivity with human strains, and acquired detectable but limited binding affinity for human-type receptors. Overall, our findings suggest that the current canine H3N2 influenza virus exhibits distinct genetic and antigenic variations from human and avian strains. Continuous molecular and serological surveillance of canine influenza viruses is therefore warranted to monitor their evolutionary trends and assess the potential for cross-species transmission. Full article

Botulinum neurotoxin serotype A (BoNT/A) is the most potent known neurotoxin. While its light chain (LC) catalytic domain is a prime target for next-generation vaccines and therapeutics, the functional differences among BoNT/A subtype LCs (A1, A2, A3) remain to be definitively characterized, despite notable sequence variation. This work aimed to systematically compare the proteolytic activity and immunoprotective efficacy of recombinant BoNT/A1-LC, A2-LC, and A3-LC. Recombinant A1-LC-His, A2-LC-His, A3-LC-His, and A3-LC-Twin-Strep proteins were expressed in Escherichia coli (E. coli) and purified with affinity chromatography. Their proteolytic activity was assessed via in vitro SNAP-25 cleavage assays. The protective potency of these antigens was evaluated in a mouse model. In vitro cleavage assays revealed a substrate cleavage efficiency order of A2-LC > A1-LC > A3-LC. In vivo, both A1-LC and A2-LC immunization conferred robust, broad protection against high-dose challenges with all three toxin subtypes. In stark contrast, A3-LC provided only minimal protection against its homologous toxin and none against heterologous subtypes. Crucially, the functional deficit of A3-LC was confirmed to be an intrinsic property, as the A3-LC-TS variant, designed to exclude tag-specific interference, exhibited comparable low efficacy. According to structural research, A3-LC’s compromised function may be caused by a four-amino-acid loss. The inferior performance of A3-LC is inherent to its primary structure. This work identified A1-LC or A2-LC as the potential proteolytic activity molecule and vaccine antigen by demonstrating functional differences among BoNT/A subtype LCs. These findings provide crucial insights for developing subtype-specific countermeasures against botulism. Full article

The global incidence of multidrug-resistant (MDR) ESKAPE pathogens—comprising Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species—has surged alarmingly in recent years, posing a significant challenge to healthcare systems worldwide. These organisms are notorious for their capacity to evade the effects of multiple classes of antibiotics, leading to treatment failures, increased morbidity and mortality, and escalating healthcare costs, all of which have placed unprecedented strain on existing infection control measures. This review encapsulates the progress in target-driven vaccine research, including the genomic discovery of highly conserved surface antigens, iron acquisition systems, biofilm- and quorum-sensing-related proteins, and computationally predicted epitopes, which are considered the most attractive targets for broad-spectrum vaccination. Novel vaccine platforms, such as outer membrane vesicles (OMVs), mRNA technologies, and multi-epitope constructs, will rapidly drive the translation of these targets into next-generation vaccine formulations. Nevertheless, challenges such as antigenic variation and immune evasion, as well as the need for a robust mucosal and cross-protective immune response, persist. The sustainability in interdisciplinary investigations are required, along with adjunctive measures and investment in the development of advanced discovery and delivery systems, to achieve the ultimate goal of successful vaccines against MDR ESKAPE infections and to mitigate the worldwide burden of antimicrobial resistance. Full article

Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, continues to be a significant global health issue, especially in Latin America, with increasing international prevalence due to migration. Despite advancements in diagnosis and treatment, it remains a neglected tropical disease characterized by significant morbidity and mortality, mainly influenced by the complex interaction between parasite diversity and host immune responses. Importantly, the remarkable genetic diversity of T. cruzi lineages also contributes to clinical heterogeneity, influencing immune evasion, therapeutic responses, and vaccine feasibility. This review analyzes the impact of immunogenetics on host–parasite interactions in Chagas disease and explores its implications for personalized therapy approaches. Recent research, particularly over the last decade, has indicated that processes including antigenic variation, extracellular vesicle-mediated regulation, and disruption of host signaling pathways facilitate parasite persistence. Host genetic variables significantly influence susceptibility, disease development, and treatment outcomes, including changes in Human Leukocyte Antigen (HLA) genes, cytokine gene polymorphisms, and immunogenetic determinants of cardiac pathology. These findings underscore the potential of immunogenetic markers as tools for prognosis and as targets for personalized therapies. However, there are still considerable research deficiencies. Inadequate comprehension of gene–environment interactions, lack of representation of varied populations, and inconsistencies in study design limit the use of immunogenetic findings in therapeutic settings. At present, the concept of personalized medicine in Chagas disease remains largely aspirational, better understood as a framework for precision public health or stratified interventions guided by host immunogenetic and parasite lineage data. Addressing these issues necessitates comprehensive genomic research, mechanistic investigations of host–parasite interactions, and clinical validation of genetic markers. This study emphasizes the necessity of incorporating immunogenetics into personalized patient management strategies based on existing evidence. This integration has the potential to improve diagnosis, enhance treatment efficacy, and inform preventive interventions, thereby advancing personalized therapy for Chagas disease. Full article

Oz virus, an emerging tick-borne thogotovirus, has been reported to cause fatal human infection in Japan. However, its ecology and geographic distribution remain largely unknown. In this study, we developed a double-antigen sandwich enzyme-linked immunosorbent assay (DAgS ELISA) for detecting Oz virus antibodies in animals and used it to conduct a seroepidemiological survey of wild boars (Sus scrofa) in Miyazaki Prefecture, Japan. Recombinant Oz virus nucleoprotein was expressed in E. coli and used as both the capture and detection antigen. Relative to the neutralization test, the DAgS ELISA showed a sensitivity of 72.2%, a specificity of 88.2%, and an overall concordance rate of 79.0%. We used this assay to examine 1045 wild boar serum samples collected between November 2022 and May 2025, finding a seroprevalence of 33.5%. The seroprevalence did not significantly differ by sex, age, or region, but showed significant seasonal variation, peaking in summer (p < 0.0001). Oz virus RNA was detected by quantitative RT-PCR in one serum sample (0.09%). Phylogenetic analysis of the partial Oz virus glycoprotein gene showed that this strain shared 98.8% nucleotide identity with the EH8 strain, which was the first Oz virus isolate obtained from ticks in Ehime Prefecture. These findings suggest that wild boars in Miyazaki are frequently exposed to Oz virus and that ticks in the region harbor the virus. However, no human cases have been reported to date. The DAgS ELISA developed in this study provides a practical tool for serological surveillance in animals. Continuous monitoring of animal populations is warranted to clarify the epidemiology of Oz virus in the region and to identify potential reservoir species. Full article

Exosome-based vaccines represent a transformative platform in modern vaccinology, combining nanoscale delivery, biocompatibility, and potent immunogenicity. Among these, the StealthX platform developed by Capricor, Inc. has demonstrated exceptional versatility, enabling antigen presentation at nanogram level doses without the need for adjuvants. Preclinical studies using StealthX have shown strong humoral and cellular immune responses against SARS-CoV-2 variants, including Delta and Omicron, as well as broader applications against influenza and RSV antigens. The platform’s ability to accommodate multiple antigens within a single formulation addresses the challenges of viral variation and facilitates multivalent “mix-and-match” immunization strategies. This review offers an in-depth evaluation of the StealthX vaccine platform, covering the biological mechanisms underlying exosome function, the engineering approaches used to load antigens, and preclinical results demonstrated across three pivotal studies. By synthesizing current evidence, this review underscores the platform’s applicability for emerging infectious diseases and explores the strategic value of multivalent exosome-based vaccines in global immunization efforts as an emerging next-generation vaccine technology. Full article

Background: Individual differences in immune responses to African swine fever virus (ASFV), whether induced by vaccination or natural infection, may be linked to genetic variation in the genes involved in antigen presentation. Methods: A total of nine pigs from the 112-population were selected for RNA-seq analysis. To pinpoint key transcription factors (TFs) regulating gene expression in the lymph nodes, weighted Kendall’s Tau rank correlation analysis was performed to link the TF binding potential with the extent of differential expression of target genes. Results: CD8⁺ T cells expressing a specific epitope of the ASFV p72 protein (ACD8⁺) accounted for 41% of the total CD8⁺ T cells in peripheral blood. A total of 2062 transcripts were identified as differentially expressed across the nine pigs (q-value < 1 × 10⁻⁸). Differential expression levels of the target genes for MECP2, ETS1, ZBTB33, ELK4, and E2F4 were significantly correlated with their TF binding potential (p < 0.05). Six SNPs were identified in the promoter region of ELK4. Analysis of the 112-pig population revealed that SNPs at S.-404A>G and S.-668C>T loci were significantly associated with ACD8⁺ levels (q-value < 0.01). Individuals with the AA genotype at S.-404A>G had significantly higher ACD8⁺ counts compared to those with AG and GG genotypes (q-value < 0.05). At the S.-668C>T locus, ACD8⁺ levels were highest in the CC genotype, followed by CT and TT genotypes, with CC showing notably higher ACD8⁺ counts (q-value < 0.05). Notably, the S.-404A>G site overlaps with potential binding sites for TFs FOXA2, GATAs, and TRPS1, while the S.-668C>T site lies within the binding regions for NR1H3, RARA, VDR, and NR1I3. Conclusion: These mutations may disrupt TFs binding to the ELK4 promoter, potentially reducing ELK4 expression and impairing antigen processing and presentation. Full article

Aflatoxin B₁ (AFB₁), a highly toxic and carcinogenic mycotoxin, poses significant public health risks due to its widespread contamination of staple food crops such as peanuts and maize. Although conventional lateral flow immunoassays (LFIAs) are widely employed for rapid on-site screening, their limited sensitivity frequently compromises accurate quantification at trace levels. To improve the analytical performance of LFIAs, we developed a novel time-resolved fluorescence-based lateral flow immunoassay (TRFN-LFIA) by integrating reverse artificial antigen labeling with time-resolved fluorescence signal amplification. This method enhances detection sensitivity and enables rapid, ultra-sensitive, visible, and quantitative determination of AFB₁ in peanut and maize samples. Under optimized conditions, the TRFN-LFIA achieved a visible limit of detection (vLOD) of 0.30 ng/mL (2.22 µg/kg), a quantitative limit of detection (qLOD) of 0.04 ng/mL (0.30 μg/kg), and a half-maximal inhibitory concentration (IC₅₀) of 0.09 ng/mL. Recoveries from spiked peanut and maize samples ranged from 81.33% to 117.86%, with coefficients of variation (CVs) below 13.04%. Analysis of 21 real samples (13 maize and 8 peanut samples) yielded results highly consistent with those obtained by liquid chromatography–tandem mass spectrometry (LC-MS/MS). Moreover, the method demonstrates significant advantages in terms of detection speed, cost-effectiveness, and operational convenience. Therefore, the results established the TRFN-LFIA method as a reliable and practical tool for on-site rapid detection of AFB₁ in contaminated food matrices, providing both a rapid and accurate approach for trace-level quantification and a novel strategy for enhancing the sensitivity of lateral flow immunoassays. Full article

Chimeric antigen receptor (CAR)-based immunotherapy has emerged as a transformative strategy in anticancer treatment, driven by advances in CAR construct design, manufacturing platforms, and expansion to diverse immune cell types. The landmark success of CD19-targeted CAR-T cell therapy in B cell malignancies has paved the way for broader clinical applications. As of 2025, the U.S. FDA has approved multiple autologous CAR-T products, underscoring their therapeutic promise. However, challenges persist, including cytokine release syndrome (CRS), neurotoxicity, product inconsistency, and the high cost and complexity of cell manufacturing. Variations in cell source, gene delivery methods, expansion protocols, and CAR design significantly influence the safety, efficacy, and scalability of these therapies. In this review, we comprehensively examine the current advances in manufacturing protocols for CAR-modified T cells, natural killer (NK) cells, and unconventional T cell subsets, including γδ T, invariant natural killer T (iNKT), and mucosal-associated invariant T (MAIT) cells. We also highlight emerging innovations such as in vivo CAR-T generation and off-the-shelf allogeneic approaches. By integrating updated strategies with a critical evaluation of current limitations, this review aims to support the development of standardized, robust, and accessible CAR-based immunotherapies. Full article

Salmonellosis remains a major cause of morbidity and mortality in low- and middle-income countries, despite the availability of effective vaccines against Salmonella enterica serovar Typhi (S. Typhi). In response, substantial efforts have been underway to develop vaccines against the key serovars responsible for invasive non-typhoidal Salmonella (iNTS) disease, such as S. Typhimurium and S. Enteritidis, as well as against S. Paratyphi A, which, together with S. Typhi, is responsible for enteric fever. The O-antigens (OAg) are considered potential protective antigens; therefore, the most advanced vaccine candidates focus on these moieties. However, no correlate of protection has been identified for either iNTS or paratyphoid fever, highlighting the importance of developing robust functional assays to assess vaccine-induced immunogenicity. In this study, we present the characterization of a high-throughput luminescence-based serum bactericidal assay (L-SBA) against multiple S. enterica serovars, using human sera. The assay was evaluated for repeatability, intermediate precision, linearity, and specificity against a panel of Salmonella strains belonging to serogroups O:4, O:9, and O:2, which were selected for their epidemiological relevance and diversity in OAg expression, quantity, and glucosylation/acetylation patterns. This assay will enable testing of clinical sera from vaccine trials to evaluate the breadth of the functional activity stimulated by current Salmonella vaccine candidates. L-SBA demonstrated an acceptable performance with all the tested strains, resulting in being linear, specific, and precise. This study also provided preliminary evidence that human sera containing antibodies against serogroup-specific OAg can efficiently kill Salmonella strains expressing OAg of the matched serovar, even in the presence of variation in OAg molecular weight, glucosylation, and acetylation. The L-SBA will enable testing of clinical sera from vaccine trials to evaluate the breadth of the functional activity stimulated by current Salmonella vaccine candidates. Full article

Background: Hepatitis B virus (HBV) remains a transfusion-transmissible infection of global concern. While mandatory screening for hepatitis B surface antigen (HBsAg) has reduced overt infections, occult hepatitis B infection (OBI) poses ongoing risk. This meta-analysis aimed to estimate the pooled prevalence of anti-HBc, HBsAg, and OBI in Saudi blood donors, as well as to assess regional variations and temporal trends. Methods: A systematic meta-analysis was conducted using nine studies published between 2013 and 2024, encompassing a total of 87,820 blood donors. Prevalence was pooled using random-effects models with logit transformation and Hartung–Knapp adjustment. Heterogeneity was quantified with I² and τ². Subgroup analyses examined geographic regions; meta-regression assessed publication year. Publication bias was evaluated with Egger’s regression; sensitivity analyses tested robustness. Results: The pooled prevalence of anti-HBc was 5% (95% CI: 3–7%), HBsAg was 0.46% (95% CI: 0.31–0.69%), and OBI was 0.12% (95% CI: 0.03–0.39%). High heterogeneity was observed (I² = 90.6–98.9%). Subgroup analyses revealed regional disparities, and meta-regression showed no significant temporal trends. Conclusions: The findings suggest that past HBV exposure remains relatively common among Saudi blood donors, while current active infection and OBI are infrequent. These results support continued enhanced screening, including anti-HBc and nucleic acid testing (NAT), to ensure transfusion safety. The lack of a national hemovigilance system that monitors transfusion-transmitted infections among recipients represents a critical gap in Saudi Arabia’s transfusion safety framework. Addressing this gap is essential to fully assess residual risks, evaluate the real-world effectiveness of screening policies, and align with global best practices in blood safety. Full article

The Japanese encephalitis virus (JEV) remains a major cause of viral encephalitis in Asia, and recent epidemiological shifts driven by the predominance of genotype I and the re-emergence of genotype V have renewed concerns regarding control efforts. Licensed vaccines have a reduced incidence of more than 90% in several endemic regions; however, evidence of reduced cross-neutralization against heterologous genotypes indicates that vaccines derived from genotype III strains may not fully match the evolving antigenic landscape. This review synthesizes current knowledge on vaccine performance, genotype-driven antigenic variation, and implications for future strain alignment. Emerging platforms, including mRNA, DNA, virus-like particles, and structure-guided recombinant antigens, have been evaluated for their potential to enhance cross-genotype breadth, scalability, and thermostability. We also summarize the progress in antiviral discovery targeting viral nonstructural proteins, host pathways, and monoclonal antibody development, along with immunomodulatory and neuroprotective strategies. Translational challenges, such as blood–brain barrier penetration, therapeutic timing, and durability of immunity, have been highlighted as key barriers to clinical application. By integrating molecular, immunological, and epidemiological evidence, this review outlines strategic directions for developing broad-spectrum vaccines and therapeutics capable of addressing the evolving genetic and ecological landscape of JEV. Full article

Background: BRCA1/2 mutations are the most recognized causes of hereditary breast cancer (BC), but their penetrance is incomplete. BRCA1-driven tumors are often chromosomally unstable and exhibit increased antigenicity. We hypothesized that inherited variations in immune-related pathways may influence BRCA1 penetrance. Methods: Case–control comparison of BC-affected versus non-affected BRCA1-mutated women is generally complicated because the latter groups are often low in numbers, represented by younger subjects and may contain relatives of the analyzed patients. We utilized a novel approach, i.e., we compared young-onset and late-onset BRCA1-associated BC cases, assuming that the early age at disease manifestation may be an indicator of increased BRCA1 penetrance. Results: NGS for 353 genes implicated in inborn errors of immunity was performed on 42 young-onset (<39 y.o.) and 35 late-onset (>57 y.o.) BC patients carrying BRCA1 pathogenic variants. This effort identified 22 potentially relevant variants, which were further analyzed in an extended cohort (up to 90 patients per group). The PRF1 p.Ala91Val variant, associated with familial hemophagocytic lymphohistiocytosis, was found in 9.6% of young-onset patients and none of the late-onset group (7/73 vs. 0/78, p = 0.005). The significance of this allele was further validated in an additional group of Russian patients (14/164 (8.5%) vs. 8/236 (3.4%), p = 0.042). This trend also retained upon the pooled analysis of Russian and Polish subjects (24/278 (8.6%) vs. 15/337 (4.4%), p = 0.045). Conclusions: Rare variants in immune-related genes, such as PRF1 p.Ala91Val, may influence BRCA1 penetrance. Broader exome-wide analyses comparing affected vs. unaffected BRCA1/2 mutation carriers, or women stratified by age at cancer onset, could help identify additional genetic modifiers of cancer risk. Full article

African swine fever virus (ASFV) is a highly contagious pathogen causing African swine fever in wild boars, warthogs and domestic pigs. The disease leads tosubstantial economic losses to the global pork industry and poses a grave threat to biodiversity. The early-encoded structural protein p22, owing to its immunodominant characteristics and high conservation across most genotypes, represents a promising diagnostic target and subunit vaccine candidate. In this study, the soluble extracellular domain of p22 protein (aa 30–177) was successfully expressed and purified, yielding 1.220 g/L. Eleven strains of monoclonal antibodies against p22 were generated, with four selected for B-cell epitope screening. Bioinformatic prediction-guided design was employed to generate overlapping truncations and peptides for epitope mapping. Based on those strategies, three novel linear B-cell epitopes were identified to be ³⁰KKQQPPKK³⁷, ¹³⁰WGTDDCTG¹³⁷ and ¹⁵⁰YVYNNPHH¹⁵⁷ by monoclonal antibodies. Sequence alignment across ASFV isolates revealed 100% evolutionary conservation in genotypes I/II, with minor variation in genotypes IV/VIII/XX/XXII. This study provided valuable data for broadening the ASFV antigen spectrum and identifying immunological targets for subunit vaccine formulation strategies. Full article