Journal of fish diseases最新文献

{"title":"Laboratory Transmission of Adult Salmon Enteritis and Associated Pathogens in Juvenile Chinook Salmon (Oncorhynchus tshawytscha).","authors":"Tamsen Polley, Claire E Couch, Connor Leong, James T Peterson, Louis M Weiss, Peter M Takvorian, Michael L Kent","doi":"10.1111/jfd.70063","DOIUrl":"https://doi.org/10.1111/jfd.70063","url":null,"abstract":"<p><p>Adult salmon enteritis (ASE), characterised by severe ulcerative enteritis, has been linked to prespawn mortality (PSM) in spring Chinook salmon (Oncorhynchus tshawytscha) in certain rivers in Oregon, USA. Catastrophic losses of spring Chinook salmon have resulted from PSM, a significant threat to their population stability. Understanding the causes of ASE is therefore critical for mitigating PSM and supporting conservation. This study investigates the potential infectious aetiology of ASE using a juvenile Chinook salmon model. Fish were immunocompromised with dexamethasone implants, fasted, and exposed to intestinal tissues from ASE-affected adult Chinook. Histopathology of recipient fish revealed mid-intestinal lesions consistent with ASE. The microsporidium Enterocytozoon schreckii, which is observed in ASE-affected adults from rivers, was transmitted for the first time to juvenile Chinook Salmon, making E. schreckii a potential new pathogen of juvenile salmon. Additionally, intranuclear inclusions were identified in enterocytes by histopathology and viral particles were detected by electron microscopy in recipient fish. The study demonstrates that intestinal lesions consistent with ASE can be experimentally induced in juvenile Chinook salmon through oral exposure to infected tissues, supporting an infectious aetiology. Further research is needed to isolate specific pathogens, including viruses and E. schreckii, and to elucidate their roles in ASE development.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":" ","pages":"e70063"},"PeriodicalIF":2.2,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145185948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative Evaluation of Oral Biofilm and Killed Cell Vaccines Against Streptococcus iniae in Four-Finger Threadfin Fish (Eleutheronema tetradactylum): Immune Response and Protection Efficacy.","authors":"Andre Giovanni, Yin-Ze Shi, Pei-Chi Wang, Ming-An Tsai, Shih-Chu Chen","doi":"10.1111/jfd.70062","DOIUrl":"https://doi.org/10.1111/jfd.70062","url":null,"abstract":"<p><p>Mariculture, a significant component of the maritime industry that focuses on marine food production, faces challenges in maintaining productivity during bacterial disease outbreaks, particularly in high-value aquaculture such as the four-finger threadfin fish in Taiwan. Streptococcosis, caused by Streptococcus iniae, is a major contributor to the mortality of the four-finger threadfin (Eleutheronema tetradactylum). Recurrent streptococcosis outbreaks have highlighted the pressing need for highly effective vaccination strategies. Given its safety, environmental friendliness, and protective effects, vaccination is widely acknowledged as an effective means of preventing aquatic diseases. An innovative approach involves using biofilm-forming S. iniae as vaccine candidates for aquaculture. This study presents an effective approach for developing a biofilm-based vaccine by cultivating S. iniae on chitosan particles, facilitating robust biofilm formation and enhancing immune responses in four-finger threadfin fish. For comparison, a formalin-killed cell (FKC) vaccine, prepared from whole-cell S. iniae, was evaluated. Immune responses were examined in the blood, mucus, and gut lavage from both the vaccinated and control groups. These responses include immune-related gene expression, antibody titers, and lysozyme activity. At 30 days post-vaccination, the biofilm vaccine group exhibited elevated antibody titers, with values of 0.23 ± 0.02 in serum, 0.09 ± 0.01 in mucus, and 0.16 ± 0.01 in gut lavage. Following vaccination, both the FKC and biofilm vaccines significantly upregulated the expression of key proinflammatory cytokines (tumour necrosis factor-α, interleukin [IL]-10, IL-12) in the spleen and kidney, indicating robust activation of the innate immune response. However, the biofilm vaccine induced markedly higher expression of these cytokines, highlighting its stronger stimulation of innate immune responses. These results suggest that the biofilm-based formulation stimulates early immune signalling pathways that are critical for protection against S. iniae infection. In the challenge experiments, the relative percent survival was of 22.85% for the biofilm and 42.8% for the FKC vaccine groups. This study demonstrates that while both FKC and biofilm vaccines activated innate and adaptive immunity, the FKC vaccine provided higher protection (RPS 42.8% vs. 22.85%), indicating that strong immunogenicity does not always translate into effective protection and that oral vaccine strategies require further refinement. Further optimisation of oral vaccine formulations is required to improve the protective efficacy of biofilm-based vaccines in aquaculture.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":" ","pages":"e70062"},"PeriodicalIF":2.2,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145149252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morphometric and Cytological Characterisation of Enlarged Basophilic Cells in Rock Bream (Oplegnathus fasciatus) During Rock Bream Iridovirus (RBIV) Infection.","authors":"Seok-Ju Lee, Su-Mi Shin, Dong-Jin Lim, Da-Seul Lee, Myung-Hwa Jung","doi":"10.1111/jfd.70064","DOIUrl":"https://doi.org/10.1111/jfd.70064","url":null,"abstract":"<p><p>Rock bream iridovirus (RBIV), a member of the Megalocytivirus genus, causes systemic infection and high mortality in rock bream (Oplegnathus fasciatus). Although enlarged basophilic cells are diagnostically relevant, their developmental trajectory and structural changes remain insufficiently characterised. This study provides the first quantitative morphometric and cytological characterisation of these cells, focusing on cytoplasmic and nuclear alterations, multinucleation and anucleation. Following oral administration of virus-containing tissue (200 mg; 6.12 × 10⁸ MCP copies), enlarged basophilic cells appeared from 11 dpi, only in fish with viral loads > 10⁶ copies/mg. Among 1664 cells analysed, mononucleate (A-1), multinucleated (two nuclei) (A-2), multinucleated (three nuclei) (A-3) and anucleate (B) types were identified. Mononucleate cells predominated at lower viral loads (over 83.1%), whereas anucleate cells comprised > 39.9% at higher loads. Exceptionally large cells with cytoplasmic axes of 50-60 μm were frequently observed. Cell and nuclear dimensions increased progressively with viral load, and multinucleate and anucleate forms predominated in fish with higher viral burdens. A schematic sequence of morphological progression from nuclear enlargement to nuclear loss is proposed as a working model, based solely on morphological evidence. Our study provides the first quantitative description of RBIV-induced enlarged basophilic cells and establishes a morphometric framework for future investigations into RBIV pathogenesis.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":" ","pages":"e70064"},"PeriodicalIF":2.2,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145137758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aeromonas veronii Infection Induces Pyroptosis in Largemouth Bass (Micropterus salmoides).","authors":"Fengyue Guo, Tao Tao, Fengyao Guo, Shun Yang, Mengmeng Huang, Hui Fei","doi":"10.1111/jfd.70059","DOIUrl":"https://doi.org/10.1111/jfd.70059","url":null,"abstract":"<p><p>Aeromonas veronii, a prevalent Gram-negative bacterium in aquaculture, poses significant health risks to economically important freshwater fish species such as largemouth bass (Micropterus salmoides). This study investigates the role of pyroptosis, a highly inflammatory programmed cell death, in the immune response of largemouth bass to A. veronii infection. We characterised key pyroptosis-associated proteins, MsGSDMEa and MsGSDMEb, which harbour two conserved Gasdermin domains and are crucial in mediating pyroptosis. Following A. veronii infection, largemouth bass exhibited a robust upregulation of inflammatory cytokines (IL-1β, IL-8, TNF-α) and increased lactate dehydrogenase (LDH) activity in serum, indicating extensive cellular damage and inflammation. Quantitative real-time PCR analysis revealed a significant upregulation of pyroptosis-related genes, including NLRP3, ASC, and caspases (Caspase-1/-3/-7), in both spleen tissue and GF-1 cell line post-infection. Western blot analysis confirmed the cleavage of GSDME, a critical step in pyroptosis execution. These findings underscore the role of pyroptosis in the immune response of largemouth bass to A. veronii infection and suggest that modulating pyroptosis could be a potential strategy for disease management in freshwater fish species.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":" ","pages":"e70059"},"PeriodicalIF":2.2,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145124712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prospection of Autochthonous Lactic Acid Bacteria Displaying Probiotic Potential to Enhance Colossoma macropomum Larvae Growth and Immunoprotection Against Aeromonas hydrophila.","authors":"Thayná M Dos Santos, Layana A B Pereira, Laine P C Dos Santos, Andrya L Lopes, Larissa A F Sampaio, Graziella V G de Matos Silva, Juliana N Ferreira, Gleika T J Dos Reis, Jonny B Teixeira, Raimundo J T Diniz-Neto, Laura G M de Carvalho, Michelle Midori Sena Fugimura, Luciano Jensen Vaz, Silvia E Plaul, Gustavo S Claudiano","doi":"10.1111/jfd.70061","DOIUrl":"https://doi.org/10.1111/jfd.70061","url":null,"abstract":"<p><p>This study assessed the functional potential of autochthonous lactic acid bacteria isolated from the gastrointestinal tract of tambaqui (Colossoma macropomum) as larviculture probiotics. Five strains were selected and identified as belonging to the genus Weissella. In vitro assays revealed high tolerance to acidic pH (2.0-3.0), resistance to bile salts (10%), biofilm formation capacity, hydrophobicity and direct Aeromonas hydrophila inhibition. In in vivo tests, strains M13 and M14 promoted significant increases in tambaqui survival (72.2% and 68.7%; p < 0.05) and growth (standard length and eye diameter), as well as water quality (nitrite reduction), highlighting multiple beneficial effects. Innate immunity was activated, with total protein level (I3 and M14) and agglutinating titre (M13 and M14) increases. Intestinal colonisation was confirmed by bacterial counts, and the observed effects were consistent with adhesive and antimicrobial strain properties. The findings demonstrate a synergistic interaction between probiotics, hosts and pathogens, with integrated health, performance and environmental stability benefits. Strains M13 and M14 are, thus, promising alternatives to the use of antibiotics in intensive aquaculture systems, contributing to sustainable and safe tropical fish production strategies.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":" ","pages":"e70061"},"PeriodicalIF":2.2,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145091895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First Molecular Detection of Mycobacterium ulcerans pseudoshottsii From Gulf Strain Striped Bass (Morone saxatilis).","authors":"Alex W Rakestraw, Kayla M Fast, Magdalene Dogbe, Sophie Picq, Joseph P Receveur, Christine Chevillon, Jean-François Guégan, Jennifer L Pechal, Heather R Jordan, M Eric Benbow, Michael W Sandel","doi":"10.1111/jfd.70060","DOIUrl":"https://doi.org/10.1111/jfd.70060","url":null,"abstract":"<p><p>Mycobacterium ulcerans pseudoshottsii is a mycolactone-producing bacterium previously isolated from Striped Bass (Morone saxatilis (Walbaum)) from Chesapeake Bay and adjacent waters of the Atlantic Coast of North America. We report the first molecular detection of this pathogen in the native Gulf strain of Morone saxatilis collected from the Pearl River, Mississippi (USA). Molecular identification was conducted using a novel PCR assay targeting the parA-625 intergenic spacer of the virulence-associated pMUM plasmid. The isolate was unambiguously assigned to M. u. pseudoshottsii based on diagnostic single nucleotide polymorphisms (SNPs) and phylogenetic analysis. This report expands the known range of M. u. pseudoshottsii to include Gulf Coast watersheds and highlights the need for enhanced surveillance in wild and aquacultured fish populations of the southern United States.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":" ","pages":"e70060"},"PeriodicalIF":2.2,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145075439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bakuchiol and Related Compounds From Psoralea glandulosa as Potent Inhibitors of Saprolegnia sp.: A Combined In Vitro and In Silico Study.","authors":"Esperanza Galvez, Evelyn Muñoz, Valentina Silva, Iván Montenegro, Alejandro Madrid","doi":"10.1111/jfd.70058","DOIUrl":"https://doi.org/10.1111/jfd.70058","url":null,"abstract":"<p><p>Saprolegnia sp., a water mold causing significant economic losses in aquaculture, necessitates sustainable alternatives to chemical treatments. This study investigated the resinous exudate of Psoralea glandulosa and its derivatives as inhibitors of Saprolegnia parasitica and S. australis . Through in vitro assays and in silico molecular docking, the research aimed to determine the inhibitory efficacy and mechanism of action of these natural compounds. The results identified 3-hydroxybakuchiol (2) as the most potent agent. It demonstrated superior minimum inhibitory concentration (MIC) values of 50 μg/mL against S. parasitica and 25 μg/mL against S. australis , surpassing the commercial control, bronopol. Its minimum oomyceticidal concentration (MOC) was also confirmed at low levels (50-75 μg/mL). Molecular docking analysis revealed that compound 2 has a high binding affinity for two crucial proteins in Saprolegnia: host-targeting protein 1 (Htp-1) and plasma membrane ATPase. These findings suggest that compound 2 acts as a potent dual inhibitor, with its free hydroxyl group being critical for its activity. This study positions 3-hydroxybakuchiol as a promising lead compound for developing new, safer, natural-based therapies to control saprolegniasis in the aquaculture industry.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":" ","pages":"e70058"},"PeriodicalIF":2.2,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145054065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oligochitosan-Ameliorated Gut Microbiome and Metabolic Homeostasis in Hybrid Groupers (Epinephelus lanceolatu ♂ × Epinephelus fuscoguttatus ♀) Infected With Vibrio harveyi.","authors":"Fei Shi, Lixin Ma, Zhilong Chen, Zhuojin He, Xiaomin Zheng, Cuiyun Zou, Chun Liu, Li Lin","doi":"10.1111/jfd.70050","DOIUrl":"https://doi.org/10.1111/jfd.70050","url":null,"abstract":"<p><p>Vibrio infections cause enteritis in grouper fish, leading to high mortality and stunted growth, which is a major challenge for aquaculture. Oligochitosans, marine prebiotics with bioactive properties, have proven their potential for growth promotion and immune regulation. However, the impacts of Vibrio harveyi on the gut microbiome of grouper fish and the potential of oligochitosans to modulate these effects remain poorly understood. This study investigates the influence of oligochitosan on the gut morphology, microbiota and metabolic patterns of hybrid grouper following low-dose infection with V. harveyi. After 8 weeks of feeding, infected groupers exhibited histopathological changes in the intestine that were mitigated by oligochitosan, as evidenced by improved villus height and intestinal wall thickness. Microbiome sequencing revealed that oligochitosan enhanced α-diversity and shifted bacterial communities, particularly increasing the abundance of Fusobacteriota and Actinobacteriota. Furthermore, the prevalence of Shewanella and Vibrio, which were more abundant in infected groupers, was reduced upon oligochitosan treatment. Metabolomic analysis indicated that lipid metabolism pathways were significantly altered in response to infection and oligochitosan intervention. Overall, oligochitosan modulates the gut microbiome and metabolite profiles, potentially protecting against V. harveyi-induced intestinal dysbiosis and metabolic disorders in hybrid groupers.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":" ","pages":"e70050"},"PeriodicalIF":2.2,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145015581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of Novel Egg Yolk Antibody (IgY)-Based Immunological Tools for the Early Detection of White Spot Syndrome Virus in Shrimp.","authors":"Kanimozhi Kumarasamy, Taju Gani, Abdul Majeed Seepoo, Nafeez Ahmed Abdul, Mohana Subramanian Bhaskaran, Maroudam Veerasami, Sahul Hameed Azeez Sait","doi":"10.1111/jfd.70056","DOIUrl":"https://doi.org/10.1111/jfd.70056","url":null,"abstract":"<p><p>The white spot syndrome virus (WSSV) is a major threat to shrimp farming and causes substantial economic losses in aquaculture. The VP28 envelope protein of WSSV facilitates initial systemic infection in shrimp. Although mammalian-derived antibodies are used for diagnostic tests, high costs and animal welfare concerns necessitate alternative strategies. This study produced specific yolk immunoglobulin (IgY) by immunising laying hens with the VP28 envelope protein as a cost-effective alternative for WSSV detection. IgY antibody titres and specificity were assessed using ELISA and western blotting, and their performance was compared with that of IgG rabbit antibodies. Stability was tested under various pH and salinity conditions. A time-course infectivity experiment analysed infection progression. Western blot analysis using IgY detected WSSV in shrimp samples at 6 h post-infection (h p.i.) in the haemolymph and eyestalk. By 12 h p.i., the gills, head soft tissue, appendages and other organs showed positive. Shrimp mortality occurred at 36 h p.i. Western blot findings matched those of IgG rabbit antibodies, proving that IgY antibodies were viable. Based on these findings, a validation study was conducted using 55 field samples collected from various regions of India. IgY serves as an innovative biological recognition component for early diagnosis of WSSV, offering an ethical and economical option for disease management in aquaculture.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":" ","pages":"e70056"},"PeriodicalIF":2.2,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144992537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pathogenicity of Aeromonas hydrophila Isolated From Diseased Largemouth Bass (Micropterus salmoides) and Development of an Inactivated Vaccine.","authors":"Guihong He, Xiaoqi Tang, Qingqing Zhou, Zhengli Wu, Yanhong Li","doi":"10.1111/jfd.70051","DOIUrl":"10.1111/jfd.70051","url":null,"abstract":"<p><p>Aeromonas hydrophila can cause disease in various aquatic animals, but there exist no effective alternatives to control its outbreak. In this study, diseased largemouth bass were collected from the breeding farm Lake Dahong (Chongqing, China), a strain SK-2 was isolated and identified as A. hydrophila. In order to investigate the pathogenicity of the strain and the protective efficacy of the inactivated vaccine, we firstly evaluated the virulence factors including hemolytic, proteolytic, and amylolytic activities. The results displayed that the diameters of hemolytic, proteolytic, and amylolytic circles reached 0.94 ± 0.10, 2.15 ± 0.16, and 1.51 ± 0.14 cm respectively. Median lethal dose (LD₅₀) was tested and the LD₅₀ value was calculated as 1.39 × 10⁵ CFU/g. Besides, a challenge test was conducted and two levels (LD₅₀ and 1/10 LD₅₀) were set for intraperitoneal injection. Significant immune responses were found in the serum and head kidney samples, with the higher superoxide dismutase (SOD), peroxidase (POD) and malondialdehyde (MDA) levels (p < 0.05). The results of qPCR revealed that tumour necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β) and interferon-γ (IFN-γ) expression levels were elevated in the liver and head kidney samples, reaching a stable state at 48 h. Furthermore, the inactivated vaccine of SK-2 was prepared using formalin and 0.85% saline (CG) and the inactivated vaccine of SK-2 (AHIV) was intraperitoneally injected for 28-d immunisation. The results indicated the SOD and lysozyme (LZM) activities in the serum of the AHIV group were dramatically higher (p < 0.05) than those in the CG group, the catalase (CAT) and MDA levels were remarkably increased (p < 0.05) compared with the CG group, and these immune-related genes exhibited conspicuous upregulation (p < 0.05), suggesting the inactivated vaccine of SK-2 could bring about subdued oxidative stress in the innate immunity of largemouth bass. The wide-type SK-2 was challenged into the largemouth bass post 28-d immunisation, and the relative protection was calculated as 86.21%. These findings provide theoretical support for the bacterial disease control of largemouth bass.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":" ","pages":"e70051"},"PeriodicalIF":2.2,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144956841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}