Veterinary Research最新文献

{"title":"Hemolysin EthA is an Edwardsiella T3SS effector that induces PANoptosis in macrophages.","authors":"Pu Yu Tang, Xiu Long Jiang, Xin Yong Zhou, Tian Tian He, Pin Nie, Hai Xia Xie","doi":"10.1186/s13567-026-01814-x","DOIUrl":"10.1186/s13567-026-01814-x","url":null,"abstract":"<p><p>Edwardsiella piscicida is an enteric intracellular bacterial pathogen. It has been reported that this bacterium produces two types of hemolysins: the secreted, pore-forming toxin HlyA and the cell-associated toxin EthA. EthA has been reported to enter epithelial cells by binding to outer membrane vesicles (OMVs) and that once inside the host cells, it releases lipopolysaccharide from the OMVs to induce pyroptosis. We report here the existence of another pathway by which EthA is secreted and delivered into host cells: the type III secretion system (T3SS) of E. piscicida. The ΔFur box-P_ethB strain that highly expresses EthA was constructed by deleting the binding motif of Fur in front of the ethB-ethA operon. The ΔFur box-P_ethB strain induces PANoptosis (a combination of pyroptosis, apoptosis and necroptosis) in a T3SS-dependent manner in murine macrophages. The highly expressed EthA stimulates pyroptosis partially via the NLRP3 inflammasome and concomittantly induces apoptosis and necroptosis, as evidenced by elevated ratios of positive cells in TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) staining, elevated protein levels of cleaved caspase-3 and phosphorylated MLKL. PANoptosis is characterized by cell swelling, membrane rupture and cell blebbing. Additionally, the highly expressed EthA inhibits the phosphorylation of the serine/threonine kinase TAK1 and transcription factor p65, preventing the nuclear translocation of phosphorylated p65 into murine macrophages. Overall, EthA has been identified as a novel T3SS substrate in E. piscicida. Its high expression inhibits the phosphorylation of TAK1, thereby increasing PANoptosis and blocking the inflammatory pathway.</p>","PeriodicalId":23658,"journal":{"name":"Veterinary Research","volume":"57 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13355344/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148424774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new recombinant avian metapneumovirus vaccine candidate provides complete protection against the novel variant infectious bursal disease virus in chickens.","authors":"Lingzhai Meng, Yuntong Chen, Mengmeng Yu, Xiaole Qi, Yongzhen Liu, Suyan Wang, Xiaoxiao Xue, Tao Zhang, Wenrui Fan, Zibo Zhang, Ying Wang, Ru Guo, Mingxue Hu, Yanping Zhang, Yulu Duan, Hongyu Cui, Yulong Gao","doi":"10.1186/s13567-026-01735-9","DOIUrl":"10.1186/s13567-026-01735-9","url":null,"abstract":"<p><p>Infectious bursal disease (IBD) is an acute, highly contagious, and immunosuppressive condition in chickens, caused by the infectious bursal disease virus (IBDV). The recent emergence of novel variant IBDV (nVarIBDV) poses a significant threat to the global poultry industry. However, currently available vaccines provide only limited protection against nVarIBDV strains. In this study, a recombinant avian metapneumovirus subtype B (aMPV/B) expressing the nVarIBDV VP2 gene (rLN16A-nVarVP2) was successfully rescued by inserting the gene between the G and L genes of the attenuated aMPV/B strain LN16-A. Immunofluorescence and Western blotting analyses confirmed stable VP2 expression in vitro. Further evaluation showed that VP2 insertion did not alter the growth kinetics of the parental virus, and the expression remained stable after 20 serial passages. A single immunization with rLN16A-nVarVP2 elicited robust humoral and cellular immune responses in specific pathogen-free chickens, inducing high levels of neutralizing antibodies against both nVarIBDV and aMPV/B, as well as Th1 (IL-2, IFN-γ) and Th2 (IL-4, IL-6) cytokines. Moreover, rLN16A-nVarVP2 conferred complete (100%) protective efficacy against both nVarIBDV and aMPV/B, fully prevented bursal atrophy and clinical signs associated with aMPV/B infection, and markedly decreased bursa viral load (nVarIBDV) and turbinate viral shedding (aMPV/B). Our findings suggest that rLN16A-nVarVP2 represents a promising live attenuated bivalent vaccine candidate for preventing infections caused by nVarIBDV and aMPV/B.</p>","PeriodicalId":23658,"journal":{"name":"Veterinary Research","volume":"57 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13355354/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148424748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oxidative stress-triggered UMPylation of SodA by YdiU modulates oxidative stress resistance in Salmonella.","authors":"Nannan Song, Li Zhai, Yingying Yue, Weiwei Wang, Cuiling Li, Qing Liu, Xinyi Wang, Yanan Wang, Zihan Shao, Junyong Yang, Zhaotai Zang, Bingqing Li, Haihong Jia","doi":"10.1186/s13567-026-01818-7","DOIUrl":"10.1186/s13567-026-01818-7","url":null,"abstract":"<p><p>YdiU is a novel UMPylation modification enzyme that plays an important role in regulating chaperones, flagellar synthesis, and iron absorption in Salmonella. Here, we report that YdiU plays an important role in regulating oxidative stress in Salmonella. The expression of ydiU was dramatically induced by hydrogen peroxide (H₂O₂) and the survivability of ∆ydiU was significantly stronger than that of WT under oxidative stress. Interestingly, in vitro and in vivo experiments showed that YdiU can interact with SodA and UMPylate it only in the presence of H₂O₂. Further study showed slight changes in the secondary structure of SodA under oxidative stress. Structural analysis of native protein and H₂O₂-treated protein showed that H₂O₂ treatment affected the conformation of Met24. The modification site Tyr12 is near Met24, and Tyr12 exposure may facilitate UMPylation by YdiU after H₂O₂ treatment. In addition, in vivo and in vitro experiments showed that YdiU negatively regulates SodA activity. Therefore, our results identify new biological functions of YdiU, highlight the importance of UMPylation in bacterial oxidation balance, and provide the theoretical basis to study Salmonella survival and pathogenesis.</p>","PeriodicalId":23658,"journal":{"name":"Veterinary Research","volume":"57 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13355359/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148424735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modification of PCNA by ISG15 plays a crucial role in porcine deltacoronavirus infection.","authors":"Cheng Li, Xiao-Ran Guo, Yu-Jin Gao, Ling-Zhai Meng, Hong-Qing Zheng, Xiu-Li Li, Zhi-Min Dong, Wei-Ke Ren, Hui-Zhong Sun, Fu-Qiang Li, Qi Zhu, Linyuan Feng, Li Zhang, Ming-Hua Yan","doi":"10.1186/s13567-026-01802-1","DOIUrl":"10.1186/s13567-026-01802-1","url":null,"abstract":"<p><p>Porcine deltacoronavirus (PDCoV), an emerging enteropathogenic coronavirus belonging to the deltacoronavirus genus, has caused massive losses to the livestock industry and poses a potential risk of cross-species transmission. Interferon-stimulated gene 15 (ISG15) plays a crucial role in virus infection and immune regulation through interactions with cellular and viral proteins. However, the mechanisms underlying the effect of ISG15 on PDCoV infection are poorly understood. In this study, we demonstrated that the knockout of ISG15, mediated by CRISPR-Cas9, facilitates PDCoV replication and that ISG15 modification (ISGylation) deficiency attenuates the antiviral ability of ISG15. To clarify the novel roles of ISG15 during PDCoV infection, we constructed a stable ISG15-overexpressed IPEC-J2 cell line. We employed tandem affinity purification followed by mass spectrometry analyses with ISG15, enabling the identification of 538 known and novel candidate ISGylation proteins including proliferating cell nuclear antigen (PCNA) which is a sign of DNA damage. We showed that ISGylation of PCNA significantly inhibited PDCoV replication. During PDCoV infection, HERC5, an ISG15 E3 ligase, interacted with PCNA and promoted its ISGylation, whereas USP18 eventually de-ISGylated PCNA. Our results not only reveal that ISGylation acts as a post-translational modification of PCNA but also elucidate the function of ISGylation in PCNA during PDCoV infection, thereby adding a novel layer of complexity to the virus-host interaction interface.</p>","PeriodicalId":23658,"journal":{"name":"Veterinary Research","volume":"57 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13356795/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148424791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Residues Y142, I143, T146, Q206, S215, R228, G267, and M268 in the surface glycoprotein of FGV-like subgroup A avian leukosis virus are the key sites determining Tva receptor binding and infectivity.","authors":"Jinqun Li, Qi Li, Yilin Yuan, Biyue Dai, Kangping Lu, Hongyan Pan, Ming Liao, Weisheng Cao","doi":"10.1186/s13567-026-01788-w","DOIUrl":"10.1186/s13567-026-01788-w","url":null,"abstract":"<p><p>Avian leukosis virus subgroup A (ALV-A) invades cells through the specific recognition of the cellular receptor Tva by its encoded surface glycoprotein gp85. Certain Fowl glioma-inducing virus (FGV) strains and their variants belong to ALV-A, but their gp85 proteins differ substantially from classical ALV-A strains. To identify the key residues in the gp85 of FGV-like ALV-A strain 2023ZW001 that determine Tva-binding affinity and infectivity, a strategy of substituting the corresponding gp85 residues between ALV-A 2023ZW001 and ALV-E ev-1 (which uses Tvb as its receptor) was adopted. A series of chimeric gp85 proteins for receptor binding assays were expressed, and multiple recombinant retroviral vectors RCASBP(ZW/ev-1)-EGFP/mCherry were constructed to transfect DF-1 cells for replication capacity analysis. The results showed that host range region 1 (hr1), host range region 2 (hr2), and variable region 3 (vr3) play a decisive role in mediating viral infection. Among these regions, residues 140-146 in hr1 and residues 267-273 in vr3 are the indispensable regions for 2023ZW001 to bind the receptor and mediate viral infection. Residues Y142, I143, and T146 in hr1; residues Q206, S215, and R228 in hr2; and as residues G267 and M268 in vr3 are the key sites determining Tva receptor binding and infectivity. This study indicated that hr1 and hr2 of the FGV-like ALV-A strain contain the major receptor interaction determinants, while vr3 also plays a key role in receptor-binding affinity and infectivity.</p>","PeriodicalId":23658,"journal":{"name":"Veterinary Research","volume":"57 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13360851/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148438136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of fowl adenovirus isolates in Taiwan: genome, antigenicity, and pathogenicity.","authors":"Lu Peng, Min Liu, Ming-Chu Cheng, Hui-Wen Chen","doi":"10.1186/s13567-026-01793-z","DOIUrl":"10.1186/s13567-026-01793-z","url":null,"abstract":"<p><p>Fowl adenoviruses (FAdVs) are important avian pathogens associated with inclusion body hepatitis and hydropericardium-hepatitis syndrome, contributing to significant economic losses in the poultry industry. Despite an increasing number of cases in Taiwan, the comprehensive characterization of circulating strains remains limited. This study investigated the molecular features, antigenic properties, and pathogenicity of FAdVs isolated in Taiwan between 2020 and 2025. Among suspected cases from broiler, layer, breeder, and colored broiler flocks, ten FAdV isolates were obtained. Whole-genome sequencing revealed six serotypes (FAdV-2, -3, -4, -8a, -8b, and -11) belonging to three species (C, D, and E), with one isolate exhibiting intertypic recombination. Cross-neutralization assays confirmed distinct serotypes with minimal antigenic overlap, highlighting the diversity of FAdVs circulating in Taiwan. A representative strain (NTU/C1120/2023) was selected for experimental infection in specific-pathogen-free chickens to evaluate pathogenicity. The isolate induced mild clinical signs and characteristic hepatic lesions in infected birds. Histopathology and immunohistochemistry further confirmed marked hepatic involvement. In addition, co-infection experiments with infectious bronchitis virus (IBV) were conducted to investigate potential interactions between the two viruses. Under co-infection conditions, FAdV viral loads in tissues were lower, whereas viral shedding tended to persist longer and antibody responses were reduced. In vitro assays using chicken embryo kidney cells further demonstrated reciprocal effects on viral replication. Collectively, this study provides new insights into the genetic and antigenic diversity of FAdVs in Taiwan and suggests that interactions with IBV may influence viral replication dynamics.</p>","PeriodicalId":23658,"journal":{"name":"Veterinary Research","volume":"57 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13348634/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148424730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correlation between the barrier function of the intestinal epithelium and susceptibility to PEDV infection in piglets at different ages.","authors":"Yabin Lu, Shuxian Li, Shanshan Yang, Caiying Wang, Yuguang Fu, Xin Huang, Jing Zhao, Han Shi, Jing Yang, Jianing Chen, Qingyong Guo, Ling Kuang, Guangliang Liu","doi":"10.1186/s13567-026-01803-0","DOIUrl":"10.1186/s13567-026-01803-0","url":null,"abstract":"<p><p>Porcine epidemic diarrhoea (PED) results in vomiting, diarrhoea, dehydration, and death in pigs. To analyse the relationship between intestinal development and susceptibility to porcine epidemic diarrhoea virus (PEDV), six new-born, 1-, 2-, 3-, 4-, and 8-week-old piglets were orally inoculated with 2 × 10⁷ copies of the PEDV strain LJX01/2014 and sacrificed 48 h after infection. The results demonstrated that PEDV infection elicits diarrhoea of diverse severity across piglets of distinct ages. Moreover, viral shedding and villous atrophy were most pronounced in neonatal piglets. With increasing age, the shedding of villi gradually decreased, resulting in significantly lower villi/crypt ratios in the duodenum of newborn, 1-week-old, and 3-week-old piglets and significantly lower villi/crypt ratios in the jejunum and ileum of newborn and 1-week-old piglets than in the control. Indirect immunofluorescence and immunohistochemistry revealed a positive correlation between intraepithelial lymphocyte counts and epithelial cells and piglet age. PEDV infection led to a significant increase in intraepithelial lymphocytes and a decrease in epithelial cells, with the most severe effects observed in newborn piglets. The numbers of goblet cells, absorptive enterocytes, and enteroendocrine cells significantly decreased, whereas the numbers of Paneth cells, stem cells, and proliferating cells significantly increased with increasing piglet age. Overall, the results indicate that intestinal tissue repair increases with increasing age. Consequently, this results in a more robust intestinal epithelial barrier and reduced PEDV-induced damage to the small intestine.</p>","PeriodicalId":23658,"journal":{"name":"Veterinary Research","volume":"57 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13348892/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148413050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recombination, mobile genetic elements, and genetic transfer contribute to the adaptation of Streptococcus uberis causing mastitis.","authors":"Anyaphat Srithanasuwan, Yang Zou, Ruth N Zadoks, Witaya Suriyasathaporn, Ynte H Schukken","doi":"10.1186/s13567-026-01795-x","DOIUrl":"10.1186/s13567-026-01795-x","url":null,"abstract":"<p><p>Streptococcus uberis is a major cause of bovine mastitis. However, the genomic mechanisms that facilitate adaptation of the pathogen within different host-associated environment or selection pressures remain poorly understood. This study analyzed whole-genome sequence data from three Thai dairy herds to investigate the contributions of recombination and mobile genetic elements (MGEs) to S. uberis evolution and adaptation. Among the 138 S. uberis genomes, 42 core genome sequence types (cgSTs) were identified, along with frequent detection of MGEs such as plasmid-associated genes (81.1% of isolates), prophages (67.4% of isolates), and insertion sequences (26.1% of isolates). The isolates from farm A exhibited the longest recombined fragment size, but with extremely low recombination frequency and recombination-to-mutation ratio. By contrast, the isolates from farm B, which had the highest prevalence of antimicrobial resistance (AMR) gene, showed a high recombination-to-mutation ratio (R/θ = 4.42) and more frequently contained MGEs associated with AMR genes. Finally, isolates from farm C shared a single core genome and AMR profile but harbored diverse prophages. Several prophages shared high sequence similarity (>99%) with phages infecting other bacterial genera, suggesting that ecological overlap between bacterial species may facilitate cross-genus genetic exchange, highlighting the influence of microbial ecology on the evolution of S. uberis. Collectively, our results illustrate the variety of mechanisms and genetic elements that contribute to the adaptive evolution of S. uberis in dairy farming environments.</p>","PeriodicalId":23658,"journal":{"name":"Veterinary Research","volume":"57 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13343983/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148406008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Immunogenicity and efficacy of a Mycoplasma hyopneumoniae/porcine circovirus type 2 combination vaccine against experimental Mycoplasma hyopneumoniae infection in pigs.","authors":"Li Wang, Filip Van Immerseel, Ilias Chantziaras, Karina Sonalio, Ana Karolina Panneitz, Xiaoyan Ma, Roman Krejci, Dominiek Maes, Bert Devriendt","doi":"10.1186/s13567-026-01808-9","DOIUrl":"10.1186/s13567-026-01808-9","url":null,"abstract":"<p><p>Vaccination is an important control measure against infections with Mycoplasma hyopneumoniae (M. hyopneumoniae), the primary pathogen of enzootic pneumonia in pigs. The present study investigated local and systemic humoral and cell-mediated immune responses and efficacy upon vaccination of piglets with a combined vaccine containing inactivated M. hyopneumoniae and porcine circovirus 2d (Cirbloc^® M Hyo, Ceva), followed by experimental M. hyopneumoniae infection (D21). Forty-five piglets were allocated to three groups, namely the not-vaccinated and infected (C) (n = 20), vaccinated and infected (V) (n = 20), and not-vaccinated and not-infected (NC) groups (n = 5). Vaccination was applied once (D0) intramuscularly. Four pigs from the V and C groups were euthanized 2 weeks post-infection (D35), and the remaining pigs 2 weeks later (D49). Blood, lung tissue, bronchoalveolar lavage fluid (BALF), and bronchial lymph nodes were collected at different timepoints. Piglets in the V group exhibited seroconversion on days 21 and 35, with markedly elevated levels of specific IgA and IgG in BALF on D35. Furthermore, the V group showed activation of interferon (IFN)-γ⁺/tumor necrosis factor (TNF)-α⁺ CD4⁺CD8α⁺ T cells and T cell proliferation on day 7, with these responses remaining elevated through D21. The concentrations of interleukin (IL)-1β, TNF-α, C-X-C motif chemokine ligand 8 (CXCL-8), and IL-17A in BALF of the C group were higher on D49, correlating with higher M. hyopneumoniae DNA loads. Clinical signs and lung lesions were less severe in vaccinated pigs. The combined vaccine elicited robust M. hyopneumoniae-specific humoral and cellular responses in blood and enhanced post-infection cellular immunity in draining lymph nodes, underscoring its protective efficacy.</p>","PeriodicalId":23658,"journal":{"name":"Veterinary Research","volume":"57 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13339504/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148406044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pathogenesis of Brucella abortus and Brucella melitensis in bovine and ovine-derived trophoblasts and macrophages and impaired intracellular trafficking of the Rev1 vaccine strain.","authors":"Aitor Elizalde-Bielsa, Maite Loperena-Barber, Christiane Pfarrer, Suzana P Salcedo, Amaia Zúñiga-Ripa, Raquel Conde-Álvarez","doi":"10.1186/s13567-026-01781-3","DOIUrl":"10.1186/s13567-026-01781-3","url":null,"abstract":"<p><p>Brucella spp. are Gram-negative facultative intracellular pathogens responsible for brucellosis, a widespread zoonosis. Among them, B. melitensis and B. abortus are the most epidemiologically relevant species, primarily infecting sheep and goats, and cattle, respectively. Upon infection, brucellae multiply within phagocytes and develop placental tropism, particularly targeting trophoblasts. Most studies of Brucella pathogenesis and vaccine development have relied on murine or human-derived epithelial and macrophagic cell lines, which may not fully reproduce the natural ruminant host. Here, we investigated whether the intracellular behaviour described for Brucella in non-natural-host models also occurs in ruminant trophoblasts (AH-1 and F3 cells) and macrophages (BoMac cells). Using confocal immunofluorescence microscopy and bacteriological assays, we observed similar infection rates for B. abortus and B. melitensis. By 24 hours post-infection (hpi), both species had transitioned to LAMP1-negative Brucella-containing vacuoles, with active replication occurring within calnexin-positive compartments. These results confirm that the Brucella intracellular trafficking previously described in non-natural-host models is conserved in these ruminant cells. Additionally, we characterised for the first time the intracellular behaviour of the Rev1 vaccine strain. Although its initial rate of infection was comparable to B. melitensis 16M, Rev1 exhibited a delay in LAMP1-exclusion from the Brucella-containing vacuole, with most bacteria remaining in LAMP1-positive compartments at 24 hpi, and showed delayed initiation of replication. These findings, together with slower in vitro growth, suggest that the Rev1 attenuation results from both delayed intracellular trafficking and impaired intracellular fitness. Our results advance the understanding of Brucella pathogenesis in natural-host and shed light on Rev1 attenuation, offering key insights to enhance current brucellosis vaccines.</p>","PeriodicalId":23658,"journal":{"name":"Veterinary Research","volume":"57 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13339977/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148406038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}