Veterinary microbiology最新文献

{"title":"Characterisation of lung cell infiltration during the early stage of infection by porcine reproductive and respiratory syndrome virus type 1 strains of different virulence","authors":"Karola Fristiková ,&nbsp;José María Sánchez-Carvajal ,&nbsp;Carmen Álvarez-Delgado ,&nbsp;Fernanda Larenas-Muñoz ,&nbsp;Macarena Rodríguez-Ruiz ,&nbsp;Inés Ruedas-Torres ,&nbsp;Inmaculada Barranco ,&nbsp;Francisco Javier Salguero ,&nbsp;Francisco José Pallarés ,&nbsp;Enric Mateu ,&nbsp;Librado Carrasco ,&nbsp;Irene Magdalena Rodríguez-Gómez ,&nbsp;Jaime Gómez-Laguna","doi":"10.1016/j.vetmic.2025.110747","DOIUrl":"10.1016/j.vetmic.2025.110747","url":null,"abstract":"<div><div>Virulent strains of porcine reproductive and respiratory syndrome virus (PRRSV) have been associated with more severe clinical signs and more pronounced interstitial pneumonia, as well as other associated lung lesions, than classical PRRSV strains. However, there is no description regarding the activation of different mechanisms linking the strain virulence with the severity of pulmonary lesions. This study aims to analyse the pulmonary cell infiltration from piglets at the early stage of infection by several PRRSV-1 strains of differing virulence. A retrospective study was carried out using lung tissue samples from piglets infected with classical (215–06, LV), moderately virulent strain (3249) and virulent (Lena, SU1-bel, and Rosalía) PRRSV-1 strains, which were evaluated by gross pathology, histopathology, and immunohistochemical methods. Immunohistochemistry was performed to detect specific cell markers, including CD163, calprotectin, CD14, CD3, CD20, and TTF-1. Piglets infected with highly virulent PRRSV-1 strains, such as Lena and Rosalía, showed more severe lung pathology, including a marked interstitial pneumonia compared to classical PRRSV-1 strains. The higher frequency of cells infiltrating the alveolar septa was made up of CD3⁺ and TTF-1⁺ cells, followed by calprotectin⁺ cells, with the higher counts being observed in the lungs of piglets infected with virulent PRRSV-1 strains, especially in those infected by Rosalía strain. The proportion of the studied cell populations was similar between strains, with no differences at the first week post-infection, which indicates that the mechanisms activated after infection with strains of different virulence may be similar but differing in intensity at this stage of infection.</div></div>","PeriodicalId":23551,"journal":{"name":"Veterinary microbiology","volume":"311 ","pages":"Article 110747"},"PeriodicalIF":2.7,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145247878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Major vault protein inhibits CSFV replication by promoting cell apoptosis","authors":"Bihao Luo ,&nbsp;Na Su ,&nbsp;Yuehan Quan ,&nbsp;Ning Li ,&nbsp;Chen Chen ,&nbsp;Liang Zhang ,&nbsp;Lei Xu ,&nbsp;Kangkang Guo","doi":"10.1016/j.vetmic.2025.110745","DOIUrl":"10.1016/j.vetmic.2025.110745","url":null,"abstract":"<div><div>Classical swine fever virus (CSFV) remains a major pathogen posing substantial threats to the global swine industry. CSFV infection modulates the expression of numerous host cell proteins, with certain factors facilitating viral replication while others exert inhibitory effects. This study investigated the influence of CSFV infection on Major Vault Protein (MVP) expression, revealing that CSFV upregulates MVP in PK-15 cells. Functional analyses demonstrated that stable MVP overexpression significantly suppressed CSFV replication, whereas MVP knockout enhanced viral propagation. Furthermore, MVP was found to upregulate pro-apoptotic proteins Bax, caspase-3, and caspase-9-while downregulating the anti-apoptotic protein Bcl-2. These results indicate that MVP promotes apoptosis and that MVP-mediated apoptotic mechanisms contribute to the inhibition of CSFV replication. Collectively, these findings suggest that CSFV-induced MVP upregulation promotes apoptosis, thereby restricting viral replication. MVP may therefore represent a promising molecular target for developing novel therapeutic interventions against CSFV infection.</div></div>","PeriodicalId":23551,"journal":{"name":"Veterinary microbiology","volume":"310 ","pages":"Article 110745"},"PeriodicalIF":2.7,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PRKAG1 mediates the anti-Japanese encephalitis virus effect of Nitazoxanide through autophagy","authors":"Hui Ma ,&nbsp;Xiaoyang Wang ,&nbsp;Chunmei Wang ,&nbsp;Wenchong Ye ,&nbsp;Wen Zhou ,&nbsp;Fengcai Zou ,&nbsp;Keyu Zhang","doi":"10.1016/j.vetmic.2025.110740","DOIUrl":"10.1016/j.vetmic.2025.110740","url":null,"abstract":"<div><div>Nitazoxanide (NTZ) not only demonstrates broad-spectrum activity against various pathogens that infect both animals and humans, but also has the capacity to induce cellular autophagy. Previous studies have indicated that NTZ may interact with PRKAG1 (AMPKγ1 subunit); however, it remains unclear whether NTZ mediates autophagy through PRKAG1 to exert antiviral effects. To investigate the potential interaction and associated biological effects between NTZ and PRKAG1, we demonstrated that NTZ can regulate the PRKAG1 protein using Western blotting and Solvent-induced protein precipitation profiling (SIP). RNA interference experiments revealed that knockdown of PRKAG1 gene expression enhances both the autophagy level in cells and their ability to inhibit the replication of Japanese encephalitis virus (JEV), with this effect showing a synergistic interaction with NTZ treatment. Conversely, PRKAG1 overexpression reduces cellular autophagy and promotes JEV replication. Phosphorylation quantitative proteomic analysis of PRKAG1-silenced cells showed that the phosphorylation levels of several key functional proteins, including TP53 and GSK3B, were significantly increased. These findings suggest that PRKAG1 modulates multiple critical cellular signaling pathways involved in promoting autophagy and antiviral responses. In conclusion, our results indicate that PRKAG1 interacts with NTZ and plays a central role in NTZ-induced autophagy and anti-JEV activity, thereby providing novel insights into the molecular mechanisms underlying NTZ’s antiviral efficacy.</div></div>","PeriodicalId":23551,"journal":{"name":"Veterinary microbiology","volume":"310 ","pages":"Article 110740"},"PeriodicalIF":2.7,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145207893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of H9N2 Avian Influenza Virus in commercial raw meat-based diets for dogs and cats in South Korea","authors":"Chang-Tae Kim ,&nbsp;Dong-Wook Lee ,&nbsp;Da-Won Kim ,&nbsp;Ji-Yun Kim ,&nbsp;Ye-Jin Lee ,&nbsp;Hee-Su Kim ,&nbsp;Seulgi Bae ,&nbsp;Jung-Hoon Kwon","doi":"10.1016/j.vetmic.2025.110741","DOIUrl":"10.1016/j.vetmic.2025.110741","url":null,"abstract":"<div><div>Raw meat-based diets (RMBDs) present inherent potential risks associated with microbial pathogen transmission that is attributed to the absence of heat treatment. Recent incidents involving highly pathogenic avian influenza (HPAI) in cats, potentially linked to RMBD consumption, underscore the urgency for assessing the risks associated with RMBDs in South Korea. In this study, 62 RMBDs produced in South Korea for consumption by dogs or cats were tested to evaluate the potential risk of avian influenza virus (AIV) contamination. Two live AIVs were isolated from two RMBDs through egg-inoculation. Entire genome sequences of the two AIVs were generated using next-generation sequencing (NGS), confirming their classification as low pathogenic avian influenza (LPAI) H9N2. Eight genes of the two isolated samples formed a monophyletic cluster with Y280-lineage H9N2 viruses that were identified in South Korea in 2020. These findings substantiate potential AIV risks associated with RMBDs, emphasizing the necessity for ongoing surveillance and viral transmission management. The implications of this study highlight the need for careful management and monitoring of RMBDs to mitigate potential zoonotic risks. Additionally, thorough control and supervision of poultry-related foods for humans are essential.</div></div>","PeriodicalId":23551,"journal":{"name":"Veterinary microbiology","volume":"311 ","pages":"Article 110741"},"PeriodicalIF":2.7,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145271298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diagnosis and genotyping of melioidosis in a domestic cat in New Caledonia","authors":"K. Laroucau ,&nbsp;A. Stefanini ,&nbsp;B. Klotoe ,&nbsp;J. Terret ,&nbsp;F. Vorimore ,&nbsp;S.A. Granier ,&nbsp;J. Colot ,&nbsp;M. Gasque ,&nbsp;B.J. Currie ,&nbsp;A. Desoutter","doi":"10.1016/j.vetmic.2025.110739","DOIUrl":"10.1016/j.vetmic.2025.110739","url":null,"abstract":"<div><h3>Objectives</h3><div>To report a case of melioidosis in a domestic cat in New Caledonia, describing the diagnostic, microbiological and molecular findings. To evaluate the potential of a glanders serological test for assessing exposure to <em>Burkholderia pseudomallei</em>.</div></div><div><h3>Methods</h3><div>A domestic cat presenting with respiratory symptoms underwent clinical and radiographic examination. Bacterial culture was performed on bronchoalveolar lavage fluid, and the strain was characterised using MALDI-TOF mass spectrometry and whole-genome sequencing. In silico multi-locus sequence typing (MLST) and phylogenetic analyses were also conducted. Serology was assessed using a commercial ELISA (GLANDA ELISA, IDVet), which was originally developed for diagnosing glanders.</div></div><div><h3>Results</h3><div><em>Burkholderia pseudomallei</em> was isolated and sequenced, revealing ST2147, which has been previously identified in New Caledonia. Phylogenetic analysis confirmed clustering with strains from the Pacific region. The cat's serum tested strongly positive by ELISA, suggesting the potential of this test for assessing exposure to <em>B. pseudomallei</em> in cats and other animals. Screening of archived feline sera identified only one additional seropositive cat, suggesting low prevalence.</div></div><div><h3>Conclusions</h3><div>This case supports the presence of multiple <em>B. pseudomallei</em> genotypes in New Caledonia and highlights the risk of melioidosis in cats. The commercial GLANDA ELISA shows promise as a tool for demonstrating animal exposure to <em>B. pseudomallei,</em> directing the need for culturing for confirmation of melioidosis. Enhanced awareness among veterinarians is essential for the early diagnosis and management of this disease in companion animals.</div></div>","PeriodicalId":23551,"journal":{"name":"Veterinary microbiology","volume":"310 ","pages":"Article 110739"},"PeriodicalIF":2.7,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145233612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emergence of cfr(C) variant in Campylobacter coli derived food-producing animal origin","authors":"Hao Li ,&nbsp;Yong Liu ,&nbsp;Shuaiwei Ge ,&nbsp;Hexiang Huang ,&nbsp;Wenjun Li ,&nbsp;Shihong Li ,&nbsp;Xiaonan Li ,&nbsp;Chenglong Li ,&nbsp;Xiang-Dang Du ,&nbsp;Chunyan Xu ,&nbsp;Hong Yao","doi":"10.1016/j.vetmic.2025.110742","DOIUrl":"10.1016/j.vetmic.2025.110742","url":null,"abstract":"<div><div><em>Campylobacter</em> is the leading cause of foodborne bacterial gastroenteritis globally. The <em>cfr</em>(C) gene encodes a 23S rRNA methyltransferase conferring cross-resistance to multiple classes of antibiotics. Here, we identified three novel <em>cfr</em>(C) variants in <em>C. coli</em> of swine origin. Compared to the original <em>cfr</em>(C), <em>cfr</em>(C)-variant-69 carried substitutions (Glu94Ala, Pro159Leu, Lys178Gln, Ile318Val), and <em>cfr</em>(C)-variant-104 and <em>cfr</em>(C)-variant-1921C17 harbored frame-shift mutations. Functional assay demonstrated that only <em>cfr</em>(C)-variant-69 conferred elevated MIC values 8-fold (florfenicol), 4-fold (chloramphenicol), and 2-fold (linezolid) compared to the parental strain NCTC 11168, respectively. In addition, a total of 67 <em>C. coli</em> isolates were identified to carry <em>cfr</em>(C) (64 from Genbank database and three from this study). WGS analysis revealed the global distribution of <em>cfr</em>(C) across five countries. MLST analysis indicated that 22 distinct sequence types were associated with <em>cfr</em>(C) dissemination, with ST1068 representing the predominant lineage. wg-MLST analysis stratified by collection time, geographic origin, and source, revealed significant clonal relatedness among strains from different years, countries, or origins. Furthermore, 18 distinct genetic environments flanking <em>cfr</em>(C) were identified among the isolates, with type 11 representing the predominant genotype [<em>hph</em>-<em>pcp</em>-<em>hp</em>-<em>aphA3</em>-<em>cfr</em>(C)-<em>hp</em>-<em>hp</em>]. Notably, the <em>cfr</em>(C) gene was flanked by multiple transposable elements (IS<em>Acsp6</em>, IS<em>Cco2</em>, IS<em>Chh1</em>, IS<em>Encal</em>, and IS<em>Sag10</em>) across different genetic contexts, in which ISA<em>csp6</em> and IS<em>Encal</em> were firstly reported. In conclusion, we identified a novel functional <em>cfr</em>(C) variant in poultry-derived <em>C. coli</em> and characterized the global dissemination of <em>cfr</em>(C), demonstrating both horizontal gene transfer and regional clonal expansion among <em>C. coli</em>. One Health genomic surveillance for <em>cfr</em>(C)-positive <em>Campylobacter</em> spp. is critical to mitigate this escalating antimicrobial resistance threat.</div></div>","PeriodicalId":23551,"journal":{"name":"Veterinary microbiology","volume":"310 ","pages":"Article 110742"},"PeriodicalIF":2.7,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145213846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to “Immunological characteristics of the recombinant pseudorabies virus with chimeric PCV Cap protein in pigs” [Vet. Microbiol. 305 (2025) 110529]","authors":"Chenhe Lu ,&nbsp;Wenjing Chen ,&nbsp;Heng Chen ,&nbsp;Gang Xing ,&nbsp;Jiayu Ma ,&nbsp;Hui Zhou ,&nbsp;Linglong Qin ,&nbsp;Da Liu ,&nbsp;Shiping Sun ,&nbsp;Peng Peng ,&nbsp;Haimin Li ,&nbsp;Yulan Jin ,&nbsp;Yan Yan ,&nbsp;Shiyue Pan ,&nbsp;Weiren Dong ,&nbsp;Jinyan Gu ,&nbsp;Jiyong Zhou","doi":"10.1016/j.vetmic.2025.110727","DOIUrl":"10.1016/j.vetmic.2025.110727","url":null,"abstract":"","PeriodicalId":23551,"journal":{"name":"Veterinary microbiology","volume":"310 ","pages":"Article 110727"},"PeriodicalIF":2.7,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145178826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Probiotic characteristics and protective effects of chicken-derived Enterococcus faecium against infection with Avian Pathogenic Escherichia coli and Salmonella in laying hens","authors":"Yanan Cui ,&nbsp;Kangping Liu ,&nbsp;Peng Chen ,&nbsp;Pengxin Jiang ,&nbsp;Xutao Wang ,&nbsp;Ning Chen ,&nbsp;Jiamei Cui ,&nbsp;Zijuan Hou ,&nbsp;Puyu Liu ,&nbsp;Jianguo Li ,&nbsp;Shishan Dong ,&nbsp;Qian Li ,&nbsp;Yan Li","doi":"10.1016/j.vetmic.2025.110738","DOIUrl":"10.1016/j.vetmic.2025.110738","url":null,"abstract":"<div><div><em>Avian Pathogenic Escherichia coli</em> (APEC) and <em>Salmonella Enteritidis</em> (SE) cause high mortality and economic losses in poultry. This study identified chicken-derived probiotics that can effectively combat APEC O78 and SE infection in laying hens. 7-day-old Dawu Jinfeng chicks naturally resistant to APEC O78 and SE infection were pre-screened and subjected to antibiotic treatments, revealing that <em>Enterococcus</em> species are crucial for maintaining resistance, as their reduction led to susceptibility and diarrhea. A total of 34 <em>Enterococcus faecium</em> (<em>E. faecium</em>) strains were isolated from the feces of resistant chicks. Three isolates (P4, C7, and 2S4) displayed <em>in vitro</em> probiotic potential by tolerating low pH and bile salts, inhibiting the growth of APEC O78 and SE, and lacking hemolytic activity and antibiotic resistance. <em>In vivo</em>, 7-day-old chicks were orally administered three doses of P4, C7, and 2S4 isolates (1 × 10⁴ CFU/mL, 1 × 10⁸ CFU/mL, 3 × 10⁸ CFU/mL) daily for 28 days. <em>E. faecium</em> administration significantly enhanced intestinal antioxidant capacity, superoxide dismutase (SOD) activity, and glutathione peroxidase (GPx) activity (all <em>P</em> &lt; 0.05), while reducing malondialdehyde levels (<em>P</em> &lt; 0.05). It also elevated secretory IgA levels in the intestinal fluid (<em>P</em> &lt; 0.05) and altered the gut microbiota composition by promoting beneficial genera (<em>Parabacteroides, Barnesiella</em>) and reducing <em>Desulfovibrio</em> abundance<em>.</em> The treatment led to a notable reduction in diarrhea and intestinal hemorrhage in chicks challenged with APEC O78 and SE. Overall, <em>E. faecium</em> isolates P4, C7, and 2S4 have significant potential as probiotics for preventing chick diarrhea caused by APEC and <em>Salmonella</em>.</div></div>","PeriodicalId":23551,"journal":{"name":"Veterinary microbiology","volume":"310 ","pages":"Article 110738"},"PeriodicalIF":2.7,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ASFV activates STAT3 to induce proviral M2 macrophage polarization","authors":"Yanru Chen ,&nbsp;Haowei Chen ,&nbsp;Weijia Zhang ,&nbsp;Penghao Lv ,&nbsp;Zhichao Wang ,&nbsp;Hanlin Liao ,&nbsp;Kaiyue Wei ,&nbsp;Qigai He ,&nbsp;Min Cui","doi":"10.1016/j.vetmic.2025.110733","DOIUrl":"10.1016/j.vetmic.2025.110733","url":null,"abstract":"<div><div>African swine fever (ASF) is an acute and highly infectious disease caused by African swine fever virus (ASFV) that has dealt a massive blow to the development of the pig industry in China. Macrophages, the primary target cells of ASFV, exhibit high plasticity. However, their phenotypic changes during infection remain poorly understood. In this study, we observed a significant increase in M2 monocytes within the peripheral blood of ASFV-infected pigs. In vitro experiments demonstrated that ASFV drives macrophage polarization toward the M2 phenotype through early phosphorylation of STAT3. STAT3 inhibition with STATTIC not only blocked M2 polarization but also suppressed ASFV replication. While M2 macrophages do not impede viral attachment or internalization, they display reduced killing capacity compared to M1 macrophages. Furthermore, in a mixed lymphocyte reaction (MLR) system, CD4⁺ T cells cocultured with ASFV-infected M2-polarized macrophages presented suppressed early activation, marked by downregulated CD25 expression, ultimately impairing adaptive immunity. These findings reveal a critical immune evasion strategy employed by ASFV and provide key insights into ASF pathogenesis and viral persistence.</div></div>","PeriodicalId":23551,"journal":{"name":"Veterinary microbiology","volume":"311 ","pages":"Article 110733"},"PeriodicalIF":2.7,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145313879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Eight-year monitoring of Mycobacterium avium subsp. paratuberculosis (MAP) infection in a herd of farmed sika deer (Cervus nippon) following known pasture contamination","authors":"Nasser Alotaibi ,&nbsp;Padraig Norton ,&nbsp;Elvira Ramovic ,&nbsp;Máire C. McElroy ,&nbsp;Viktor Perets ,&nbsp;Damien Farrell ,&nbsp;Stephen V. Gordon ,&nbsp;Hanne Jahns","doi":"10.1016/j.vetmic.2025.110737","DOIUrl":"10.1016/j.vetmic.2025.110737","url":null,"abstract":"<div><div>Paratuberculosis (PTB), a chronic granulomatous enteritis caused by <em>Mycobacterium avium</em> subsp. <em>paratuberculosis</em> (MAP), results in considerable economic losses in deer farming globally. Transmission mainly occurs via the faecal-oral route when the environment is contaminated by subclinically infected deer shedding MAP. Field studies on the spread of disease in naturally infected sika deer do not exist. In this short communication, we report on the 8-year close monitoring of a small sika deer herd on year-round grazing to investigate MAP transmission after a subclinically MAP infected stag B33 had been inadvertently introduced. On a monthly basis, pooled faecal samples were collected from the pasture between January 2017 and 2019 and analysed for MAP detection. Full postmortems were conducted of all animals from the herd (n = 36) and the infection status was investigated by MAP liquid culture on faeces (n = 36), ileocaecal lymph nodes (n = 33) and ileum samples (n = 29). Further, samples of ileum, ileocaecal lymph nodes and relevant gross lesions were examined by histopathology (n = 36) and ELISA was conducted on serum samples (n = 29). MAP was consistently absent from pooled faecal samples collected from the pasture. Despite identifying the stag B33 as a moderate and low shedder on two occasions, none of the other deer got infected over the 8 years of monitoring. Culture and whole genome sequencing identified the MAP isolate as Type C (cattle) strain. This suggests that a subclinically infected sika deer may pose a lower risk for transmission of MAP than anticipated and raises the question of other possible sources to initiate disease in deer herds.</div></div>","PeriodicalId":23551,"journal":{"name":"Veterinary microbiology","volume":"310 ","pages":"Article 110737"},"PeriodicalIF":2.7,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}