Fish & shellfish immunology最新文献

{"title":"Impacts of encapsulated azadirachtin (Azadirachta indica) in the diet of Nile tilapia (Oreochromis niloticus)","authors":"Matheus Berlofa Ferreira ,&nbsp;Gabriel Antonio Cuzma Costa ,&nbsp;Paola Capistrano dos Santos ,&nbsp;Domickson Silva Costa ,&nbsp;Vanessa Perenguez Riofrio ,&nbsp;Camila Lisarb Velasquez Bastolla ,&nbsp;Miguel Saldaña-Serrano ,&nbsp;Marília Tedesco ,&nbsp;Gracienhe Gomes dos Santos ,&nbsp;Maria Clara Miguel Libanori ,&nbsp;Caio Francisco Santana Farias ,&nbsp;Bruno Corrêa da Silva ,&nbsp;Alexsandra Valério ,&nbsp;Afonso Celso Dias Bainy ,&nbsp;Mauricio Laterça Martins ,&nbsp;Marco Shizuo Owatari ,&nbsp;José Luiz Pedreira Mouriño","doi":"10.1016/j.fsi.2026.111156","DOIUrl":"10.1016/j.fsi.2026.111156","url":null,"abstract":"<div><div>Various plant-based products are currently undergoing testing in aquaculture as growth and/or health enhancers for fish, serving as substitutes for chemicals and antibiotics that may be detrimental to animal and consumer well-being. Azadirachtin is a bioactive compound extracted from the <em>Azadirachta indica</em> plant, with great microbicidal and immunostimulant potential. The aim of this study was to evaluate the effects of dietary azadirachtin supplementation on the zootechnical performance and health of juvenile Nile tilapia (<em>Oreochromis niloticus</em>) reared in a recirculating aquaculture system. Juvenile tilapia (<em>n</em> = 400; mean weight 13.03 ± 0.77 g) were randomly distributed into 20 experimental units (EUs) divided into five groups with four replicates each. Over a 45-day period, four groups were given diets containing azadirachtin at concentrations of 20, 70, 120, and 170 mg kg⁻¹, while a control (0 mg kg⁻¹) group was fed a diet without the compound. At the end of this period, assessments were conducted on growth performance, haematoimmunological parameters, histological conditions of the liver, spleen, kidney, and intestine, as well as analyses of intestinal microbiota, hepatic antioxidant enzymatic activity, and malondialdehyde content. No significant differences were found in growth performance, whereas the inclusion of 170 mg kg⁻¹ of azadirachtin resulted in higher antimicrobial activity of fish blood plasma against <em>Aeromonas hydrophila</em> and lower intestinal <em>Streptococcus</em> spp. counts compared to non-supplemented fish. The mean corpuscular haemoglobin concentration was significantly lower in fish from the 170 mg kg⁻¹ treatment group than in the control group. Conversely, dietary inclusion of azadirachtin adversely affected the structure and overall health of organs, especially the kidney and liver. Malondialdehyde content in the hepatic tissue of Nile tilapia was significantly higher in fish from the 120 mg kg⁻¹ treatment than in the 20 mg kg⁻¹ treatment and the control group. Fish from the 120 and 170 mg kg⁻¹ treatments showed a significant increase in superoxide dismutase activity compared to the control group. Although some beneficial effects on immunity have been observed, such as increased agglutination titre and enhanced antimicrobial activity of fish blood plasma against <em>A. hydrophila</em>, as well as reduced levels of <em>Streptococcus</em> spp. in the intestine, caution is advised when incorporating azadirachtin into the diet of juvenile <em>O. niloticus</em> as it may have the potential to compromise the integrity of tissues in vital organs.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111156"},"PeriodicalIF":3.9,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146057336","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":"Integrated immune responses in Manila clam: Antimicrobial activity, immune-related enzymes activity and gene expression profiles following Vibrio anguillarum challenge","authors":"Yongchao Li,&nbsp;Tianshuo Huang,&nbsp;Pengxiang Lin,&nbsp;Jie Yu,&nbsp;Hongtao Nie","doi":"10.1016/j.fsi.2026.111166","DOIUrl":"10.1016/j.fsi.2026.111166","url":null,"abstract":"<div><div>This study examines the innate immune response of the Manila clam (<em>Ruditapes philippinarum</em>) to <em>Vibrio anguillarum</em> infection. Clams were experimentally challenged with <em>V. anguillarum</em>, and samples were collected at different time to assess hemocyte counts, antibacterial and bacteriolytic activity, acid phosphatase (ACP) and lysozyme (LZM) activity, and expression of immune-related genes (<em>CTL-3</em>, <em>Defensin</em>, <em>NFκB1</em>, <em>IκBα</em>, <em>TNF-αL</em>, <em>IL17</em>). Results showed a significant increase in total hemocyte count after <em>V. anguillarum</em> challenge. Antibacterial activity in hemolymph peaked at 6 h post challenge (hpc) with a 2.2-fold increase, while bacteriolytic activity reached 2.4-fold at 24 hpc. ACP activity in hepatopancreas and gills peaked at 12 hpc (1.3- and 1.6-fold increases), and LZM activity peaked at 6 hpc (1.4- and 1.5-fold). Gene expression was dynamically upregulated in a tissue-specific manner, with key genes such as <em>CTL-3</em>, <em>Defensin</em>, and <em>NFκB1</em> showing early peaks in hepatopancreas. The concentration of TNF-α and IL17 also rose significantly after <em>V. anguillarum</em> challenge. The concentration of TNF-α showed a significant difference from the control group at 6–72 hpc (<em>P</em> &lt; 0.05), and the concentration of IL17 showed a significant difference from the control group at 24–72 hpc (<em>P</em> &lt; 0.05). These findings demonstrate that <em>V. anguillarum</em> induces a rapid and integrated immune response in Manila clam, involving both cellular and humoral components, and provide new insights into bivalves innate immunity.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111166"},"PeriodicalIF":3.9,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146085017","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":"Butyrate-induced trained immunity enhances bacterial killing ability of head kidney macrophages in turbot (Scophthalmus maximus L.)","authors":"Shu Zhao ,&nbsp;Jinjin Zhang ,&nbsp;Wentao Wang ,&nbsp;Shufei Liang ,&nbsp;Mengqi Chen ,&nbsp;Rui Shao ,&nbsp;Xinmeng Liao ,&nbsp;Qinghui Ai ,&nbsp;Kangsen Mai ,&nbsp;Min Wan","doi":"10.1016/j.fsi.2026.111165","DOIUrl":"10.1016/j.fsi.2026.111165","url":null,"abstract":"<div><div>Trained immunity represents an evolutionarily conserved form of innate immune memory established through epigenetic and metabolic reprogramming. This study has demonstrated for the first time that butyrate, a key gut microbiota-derived metabolite, induces trained immunity in teleost macrophages. Our results revealed that priming head kidney macrophages (HKMs) from turbot (<em>Scophthalmus maximus</em> L.) with 1 μM of sodium butyrate (NaB) for 24 h followed by a 5-day training period, established a durable memory phenotype of HKMs. Importantly, the bactericidal capacity against <em>Edwardsiella tarda</em> (<em>E.</em> <em>tarda</em>) infection was significantly enhanced in butyrate-trained HKMs, accompanied by the elevated pro-inflammatory response with significantly elevated expression of <em>il</em><em>-</em><em>1β</em> and <em>tnf</em><em>-</em><em>α</em>. Mechanistically, butyrate training activated the HIF-1α signaling pathway, modulated a late-phase metabolic shift towards anaerobic glycolysis and TCA cycle, evidenced by altered citrate metabolism and glutamine pathway activation. Furthermore, the gene expression of <em>acly</em>, <em>acss1</em> and <em>acss2</em> was increased, while the expression of <em>acc1</em> was suppressed, leading to the increased acetyl-CoA pools. On the other hand, butyrate induced persistent epigenetic remodeling, evidenced by increased expression of histone acetyltransferase CBP/P300, HDAC3 suppression, and a robust accumulation of H3K27 acetylation. Remarkably, <em>in vivo</em> pretreatment with butyrate at a low dose conferred a 20 % survival advantage against a lethal <em>E. tarda</em> challenge in juvenile turbot after 14 days post-exposure to butyrate compared to that in control group. These findings have established that butyrate drives innate immune memory in fish, offering novel insights and a promising candidate for prophylactic strategies against pathogenic infection in aquaculture.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111165"},"PeriodicalIF":3.9,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146085014","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":"Robigenin in combating largemouth bass ranavirus: Investigating the antiviral potency and underlying mechanisms","authors":"Wenyu Liao ,&nbsp;Lin Huang ,&nbsp;Jieying Yu ,&nbsp;Mingzhu Liu ,&nbsp;Nijia Xue ,&nbsp;Junxiang Lai ,&nbsp;Ermeng Yu ,&nbsp;Fei Ling ,&nbsp;Shuyu Han ,&nbsp;Ying Pan ,&nbsp;Pengfei Li ,&nbsp;Qing Yu","doi":"10.1016/j.fsi.2026.111163","DOIUrl":"10.1016/j.fsi.2026.111163","url":null,"abstract":"<div><div>The largemouth bass ranavirus (LMBV) represents a significant pathogen causing severe damage to the aquaculture industry, for which specific prevention and control measures are currently lacking. This study systematically evaluated the anti-LMBV activity of the natural flavonol compound robigenin and elucidated its underlying molecular mechanisms through both in <em>vitro</em> cell experiments and in <em>vivo</em> infection models. The results demonstrated that robigenin at concentrations ≤6.25 μg/mL exhibited no significant cytotoxicity to the fathead minnow cells (FHM). Within this concentration range, its anti-LMBV efficacy increased in a dose-dependent manner. Robigenin was found to inhibit LMBV infection by blocking viral entry and replication phases without interfering with virus-receptor binding. Additionally, the results revealed that robigenin upregulated the expression of interferon-related genes, including <em>IRF3</em>, <em>IRF7</em>, <em>IFN</em>, <em>ISG15</em>, and <em>MAVS</em>, thereby enhancing cellular immune responses. In <em>vivo</em> experiments further confirmed that robigenin significantly alleviated LMBV-induced symptoms in juvenile <em>Micropterus salmoides</em> and markedly improved survival rates. In conclusion, this study provides the first evidence that robigenin effectively suppresses LMBV infection, offering both a promising candidate compound and theoretical foundation for the eco-friendly control of aquatic viral diseases.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111163"},"PeriodicalIF":3.9,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146085051","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":"Vertical transmission of Edwardsiella ictaluri in laboratory zebrafish revealed by highly-sensitive single molecule RNA in situ hybridization","authors":"Chaofan Wang ,&nbsp;Liyue Liu ,&nbsp;Houpeng Wang ,&nbsp;Jiangyue Lei ,&nbsp;Jiang Zeng ,&nbsp;Yonghua Sun ,&nbsp;Ding Ye","doi":"10.1016/j.fsi.2026.111159","DOIUrl":"10.1016/j.fsi.2026.111159","url":null,"abstract":"<div><div><em>Edwardsiella ictaluri</em> (<em>E. ictaluri</em>) is a significant bacterial pathogen responsible for severe losses in freshwater aquaculture and poses emerging concerns for laboratory zebrafish (<em>Danio rerio</em>) colonies. Although previous studies have suggested the potential for intergenerational or vertical transmission of <em>E. ictaluri</em>, direct experimental evidence supporting this hypothesis has remained lacking. In this study, we developed a hybridization chain reaction–enhanced single-molecule fluorescence in situ hybridization (HCR-smFISH) assay that enables highly sensitive, single-cell– and single-molecule–level detection of <em>E. ictaluri</em> within host tissues. Using an established zebrafish infection model, we characterized the tissue tropism and spatial distribution of the pathogen in key immune and metabolic organs, including the spleen, gills, and liver. Notably, whole-embryo imaging provided direct evidence of maternally mediated transmission, demonstrating that bacterial signal adhere to the chorion surface of eggs. Subsequent disinfection trials demonstrated that NaClO surface sterilization effectively eliminated egg-associated bacteria and alleviated infection-induced inflammatory responses in the progeny. Collectively, these findings fill a critical knowledge gap regarding the vertical transmission of <em>E. ictaluri</em> and offer practical guidance for disease prevention, broodstock management, and the establishment of specific pathogen-free zebrafish lines in research and aquaculture settings.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"170 ","pages":"Article 111159"},"PeriodicalIF":3.9,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146074608","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":"The RNA sensor MDA5 contributes to the antiviral immune response in Crassostrea gigas by modulating the MAVS-mediated signaling pathway","authors":"Yingmei Xu ,&nbsp;Yuhao Jin ,&nbsp;Mengjia Chen ,&nbsp;Yuqing Zeng ,&nbsp;Yiqing Wang ,&nbsp;Xiaoyu Gu ,&nbsp;Xue Qiao ,&nbsp;Lingling Wang ,&nbsp;Linsheng Song","doi":"10.1016/j.fsi.2026.111160","DOIUrl":"10.1016/j.fsi.2026.111160","url":null,"abstract":"<div><div>Melanoma differentiation–associated gene 5 (MDA5) is a key member of the RIG-I-like receptor (RLR) family that detects viral RNA in the cytoplasm and triggers antiviral innate immunity mainly via the MAVS-dependent signaling cascade. In the present study, a MDA5-like homologue (<em>Cg</em>MDA5) containing two N-terminal CARD domains, a central DExD/H-box helicase domain and a C-terminal domain (CTD) was identified from Pacific oyster (<em>Crassostrea gigas</em>). <em>Cg</em>MDA5 mRNA transcripts were detected in all examined oyster tissues, with the highest level in haemocytes. The mRNA expression of <em>Cg</em>MDA5 in haemocytes was significantly upregulated by poly (I:C) and 5′-ppp dsRNA stimulation. <em>Cg</em>MDA5 protein exhibited strong <em>in vitro</em> binding activity toward poly (I:C) and dsRNA of 100 bp and 1000 bp in length, with a marked preference for longer dsRNA. The interaction of <em>Cg</em>MDA5 and <em>Cg</em>MAVS was detected and affirmed by Co-IP after transfection into HEK293T cells. In <em>Cg</em>MDA5-RNAi oyster, the mRNA expression level of <em>Cg</em>MAVS was down-regulated post poly (I:C) stimulation. Moreover, both RNAi of <em>Cg</em>MDA5 and <em>Cg</em>MAVS down-regulated the mRNA expression of <em>Cg</em>IRF1, <em>Cg</em>IRF8 and <em>Cg</em>IFNLP. These findings collectively suggest that <em>Cg</em>MDA5 is capable of interacting with <em>Cg</em>MAVS, thereby activating the <em>Cg</em>IRF-<em>Cg</em>IFNLP signaling pathway to mediate antiviral immune responses in oyster.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111160"},"PeriodicalIF":3.9,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146112653","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":"Two interleukin-1β types reinforce innate immune response modulation in Japanese medaka, Oryzias latipes","authors":"Mizanur Rahman Washim ,&nbsp;Natsuki Morimoto ,&nbsp;Takechiyo Sumiyoshi ,&nbsp;Aki Nishihara ,&nbsp;Siva Nallaperumal ,&nbsp;Tomoya Kono ,&nbsp;Jun-ichi Hikima","doi":"10.1016/j.fsi.2026.111157","DOIUrl":"10.1016/j.fsi.2026.111157","url":null,"abstract":"<div><div>Interleukin-1β is a pro-inflammatory cytokine with pluripotent roles in mediating immune response. In fish, IL-1β plays a major role in inflammatory responses to pathogenic infections, though its immunological functions through direct stimulation have not been studied in detail. In this study, two IL-1β genes (<em>il1b1</em> and <em>il1b2</em>) from the Japanese medaka (<em>Oryzias latipes</em>) were identified and characterized. The broad immunostimulatory effects of recombinant IL-1β (OlrIL-1β) from Japanese medaka were explored using embryonic fibroblast-like cell line (OLHdrR-e3) and primary cultured kidney cells. Recombinant proteins were produced via prokaryotic expression based on predicted mature isoforms IL-1β1_Asp⁹⁵ (type II) and IL-1β2_Asp¹²¹ (type I) to investigate their distinct functional characteristics. Then, their immune-related gene expression, phagocytosis, and reactive oxygen species (ROS) production ability were evaluated <em>in vitro</em> and <em>ex vivo</em>. rIL-1β triggers the expression of not only pro-inflammatory cytokines such as <em>il1b</em>, <em>tnfa</em>, <em>il6</em>, <em>il8</em>, <em>mcp1b</em>, and <em>csf1b</em><em>,</em> but also the antimicrobial peptide, <em>def1b</em>. Additionally, they upregulate the expression of cell specific markers, including macrophage- and granulocyte-specific genes <em>mpeg1.1</em>, <em>mpx2</em>, and <em>epx</em>, and nitric oxide synthase (NO) gene <em>nos1</em>. Moreover, medaka OlrIL-1β proteins exhibited robust phagocytosis and superoxide anion production ability than those in unstimulated control. In all evaluations, the OlrIL-1β proteins corresponding to the predicted cleavage sites exhibited strong immune activation, with type I OlIL-1β2_Asp¹²¹ demonstrating more potent response than type II. To our knowledge, this is the study to reveal the immunomodulatory functions of Japanese medaka IL-1β, highlighting its potential in immunotherapy for disease prevention and control in aquaculture.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111157"},"PeriodicalIF":3.9,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090451","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":"Mechanism of Pseudomonas plecoglossicida T6SS effector vgrG1a in disrupting hepatic immunometabolic homeostasis in large yellow croaker","authors":"Peng Xizhi ,&nbsp;Sun Yujia ,&nbsp;Li Haoyang ,&nbsp;Yan Qingpi","doi":"10.1016/j.fsi.2026.111147","DOIUrl":"10.1016/j.fsi.2026.111147","url":null,"abstract":"<div><div><em>Pseudomonas plecoglossicida</em>, a significant pathogen of large yellow croaker (<em>Larimichthys crocea</em>), employs its Type VI secretion system (T6SS1) as a key virulence determinant. However, the role of the T6SS1 spike protein, VgrG1a, in pathogenesis remains poorly understood. This study elucidates the critical function of <em>vgrG1a</em> in disrupting hepatic immunometabolic homeostasis by constructing a <em>vgrG1a</em> deletion mutant (Δ<em>vgrG1a</em>). We found that the Δ<em>vgrG1a</em> strain exhibited markedly attenuated virulence, increasing host survival by 40 % compared to wild-type challenge. Histopathological and ultrastructural analyses revealed that <em>vgrG1a</em> deletion significantly alleviated hepatic vacuolar degeneration, inflammatory infiltration, glycogen depletion, and mitochondrial damage. Physio-biochemical assays demonstrated that the metabolic disturbances in ATP synthase activity, NAD⁺/NADH ratio, and glutathione content were considerably milder in the Δ<em>vgrG1a</em>-infected group. Proteomic and qRT-PCR analyses indicated that <em>vgrG1a</em> activates a robust pro-inflammatory cytokine storm via the Toll-like receptor 2 (TLR2) and nucleotide-binding oligomerization domain-containing protein 2 (NOD2) signaling pathways. Concurrently, it potently suppressed the AMPK signaling pathway and the expression of key metabolic genes involved in gluconeogenesis (Pck1) and fatty acid <em>β</em>-oxidation (Acaa2). Our findings demonstrate that <em>vgrG1a</em>, as a key T6SS1 component, drives hepatic immunometabolic dysregulation by coordinately activating innate immune responses and inhibiting AMPK-mediated energy metabolism, providing novel insights into the pathogenesis of microbes.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"170 ","pages":"Article 111147"},"PeriodicalIF":3.9,"publicationDate":"2026-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146051100","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":"Population-specific transcriptomics of Pacific oyster after exposure to a highly pathogenic, globally distributed virus","authors":"Bernarda Calla ,&nbsp;Neil F. Thompson ,&nbsp;Colleen A. Burge","doi":"10.1016/j.fsi.2026.111154","DOIUrl":"10.1016/j.fsi.2026.111154","url":null,"abstract":"<div><div>Disease outbreaks in marine invertebrates, particularly in cultivated species, have increased as stressful environmental conditions become more frequent. The Ostreid herpesvirus and its microvariants have caused substantial mortalities in Pacific oysters globally, heavily impacting aquaculture production in localities where the virus becomes established. This study investigates the molecular response of Pacific oysters to OsHV-1 μVar infection in two oyster populations: a population of Miyagi oysters, and a population of Midori oysters. Although viral infection elicited a general and significant up-regulation of antiviral defense transcripts that was very similar in both populations and that included RIG-I like receptors and the interferon-like pathway, gene-wise clustering analyses clearly differentiated both populations. Among differences between Midori and Miyagi were several immunity-related genes and histone-coding genes that indicated possible pre-transcriptional mechanisms of gene regulation influencing disease outcomes. Among other differences, genes encoding for viral sensing proteins (SAMD9 and NFX-1 zinc finger) showed higher basal and infection-induced expression in Midori, whereas Miyagi oysters exhibited greater up-regulation of ubiquitination pathways. We also compared the general response of Pacific oysters to different OsHV-1 μVars strains, concluding that there is no marked difference between the oyster response to a U.S. OsHV-1 μVar compared to an Australian μVar. These results are important for future work that focuses on developing Pacific oysters that are tolerant to OsHV-1 μVars and to develop additional management strategies to prevent the spread of this viral disease.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111154"},"PeriodicalIF":3.9,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146046006","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":"Pathogen coinfections in wild and farmed salmonids: A systematic review","authors":"Yessica Ortega ,&nbsp;Débora Torrealba ,&nbsp;José Gallardo-Matus ,&nbsp;Fernanda Fernández ,&nbsp;Carolina Figueroa ,&nbsp;Paulina Bustos ,&nbsp;Pablo Conejeros ,&nbsp;Brian Dixon ,&nbsp;Marcos Mancilla","doi":"10.1016/j.fsi.2026.111155","DOIUrl":"10.1016/j.fsi.2026.111155","url":null,"abstract":"<div><div>Coinfections have been reported in a wide range of organisms, including wild and farmed salmon and trout. However, the effects of coinfections on host resistance to pathogens remain poorly understood. A primary pathogen can modulate the host's immune response to subsequent infections, either by suppressing or priming the immune system. However, in some cases, pathogens may compete within the same host, potentially reducing or neutralizing the severity and impact of the disease. This systematic review examines the impacts of coinfections on farmed and wild salmonids, synthesizing evidence from 146 studies that met the eligibility criteria. Field evidence from 90 studies demonstrates that pathogen coinfections are widespread in salmonids across diverse geographic regions and aquatic environments. Coinfections were most frequently reported in Atlantic salmon and rainbow trout but were also documented in multiple wild salmonid species, indicating that coinfection is a pervasive phenomenon across the Salmonidae family. Complex coinfections involving three or more pathogens were common, and among pairwise interactions, parasite–parasite, virus-virus and bacteria–bacteria coinfections predominated. Experimental evidence shows that both intra- and interspecific coinfections strongly influence disease outcomes in salmonids. Notably, strategies to mitigate coinfection remain poorly explored, and there is still limited understanding of how host immune responses shape pathogen–pathogen interactions. Overall, coinfection emerges as a context-dependent and underappreciated driver of disease risk across wild and farmed salmonids, highlighting the need to strengthen disease surveillance frameworks through explicit coinfection reporting, as current monitoring approaches likely underestimate its frequency and epidemiological relevance.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"170 ","pages":"Article 111155"},"PeriodicalIF":3.9,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146045842","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}