Fish & shellfish immunology最新文献

{"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":"2026-04-01","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":"Silver nanoparticles treatment for Aeromonas hydrophila infection in Nile tilapia (Oreochromis niloticus): In vivo and in vitro study","authors":"Basma H. Moustafa ,&nbsp;Rawda G. Massoud ,&nbsp;Mona A. Malash","doi":"10.1016/j.fsi.2026.111100","DOIUrl":"10.1016/j.fsi.2026.111100","url":null,"abstract":"<div><div>Bacterial infections present major challenges in aquaculture, especially for Nile tilapia. <em>Aeromonas</em> species are commonly associated with diseases in freshwater fish. Silver nanoparticles (AgNPs) are promising for use in aquaculture due to their antibacterial, antifungal, and antiviral properties. This study investigates in vitro and in vivo reactions to low concentrations of silver nanoparticles (AgNPs) as an antibacterial solution against <em>Aeromonas hydrophila</em>, aiming to find an alternative remedy for this pathogen, particularly one that exhibits resistance to numerous antibiotics. Four aquariums contained fish acclimated to 1, 3, 6, and 12 μg/L of AgNPs, which were dissolved in water for three weeks. Then, 0.2 ml of <em>A. hydrophila</em> (1 × 10⁸ CFU/ml) was injected intraperitoneally, and the fish were monitored over five days. Our results demonstrated that the incorporation, even at lower concentrations, of a single dose of AgNPs (1 μg/L), caused blood immune cell activation (lymphocytes, neutrophils, monocytes, and Eosinophils). Plasma glucose levels decreased, as did triglycerides and cholesterol levels. ALT and AST in general also declined. This research investigated the effectiveness of silver nanoparticles (AgNPs) as an antibacterial solution against <em>A. hydrophila</em>, particularly in cases of antibiotic resistance. The findings suggest that AgNPs may be safely used in aquarium water at concentrations of 1, 3, and 6 μg/L to combat this pathogen. They not only act as a bactericidal agent but also enhance fish immunity, reducing mortality from infections. The minimum bactericidal concentration (MBC) for Nile tilapia (<em>Oreochromis niloticus</em>) can be achieved at 1 μg/L in aquarium water.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"170 ","pages":"Article 111100"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923757","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":"Establishment of a caudal fin cell line from largemouth bass (Micropterus salmoides) and its transcriptomic response to largemouth bass virus infection","authors":"Jingting Qi ,&nbsp;Wenting Wang ,&nbsp;Yimeng Liu ,&nbsp;Qiao Huang ,&nbsp;Mingli Liu ,&nbsp;Chaoguang Wei ,&nbsp;Yuang Jiang ,&nbsp;Zhichao Wu ,&nbsp;Zhitao Qi ,&nbsp;Jiulin Chan ,&nbsp;Peng Hu","doi":"10.1016/j.fsi.2026.111122","DOIUrl":"10.1016/j.fsi.2026.111122","url":null,"abstract":"<div><div>The largemouth bass (<em>Micropterus salmoides</em>), commonly known as the California bass, is a species of significant economic importance in global freshwater aquaculture. Largemouth bass virus (LMBV) has emerged as a major pathogen that poses a substantial threat to the sustainability of largemouth bass aquaculture. In this study, we established a novel Micropterus salmoides caudal fin (MSCF) cell line that supports LMBV propagation and enables investigation of virus-induced fundamental patterns of molecular responses. Characterization of the MSCF line revealed an initial mixture of epithelial-like and fibroblast-like cells that became uniformly epithelial by passage 20. Transcriptomic analysis revealed that LMBV infection significantly altered the transcription levels of 262 genes (201 up-regulated genes and 61 down-regulated), which were functionally enriched in key antiviral pathways such as apoptosis, FoxO signaling, and RIG-I-like receptor signaling. The observed expression patterns suggest that LMBV employs a potential strategy to manipulate host cell survival and disrupt innate immune responses. Collectively, we have developed an LMBV-susceptible cell line (MSCF), which provides an ideal platform for studying LMBV virology and elucidating the host defense mechanisms against LMBV.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"170 ","pages":"Article 111122"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974594","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":"Streptococcus agalactiae 1a capsule (cpsE) and hemolysin (cylE) deletion mutants display attenuated virulence in Nile tilapia (Oreochromis niloticus)","authors":"Kjetil Fyrand ,&nbsp;Cheng Xu ,&nbsp;Ephrem Debebe Zegeye ,&nbsp;Morten Kjos ,&nbsp;Øystein Evensen","doi":"10.1016/j.fsi.2026.111097","DOIUrl":"10.1016/j.fsi.2026.111097","url":null,"abstract":"<div><div><em>Streptococcus agalactiae (S. agalactiae)</em>, also known as Group B <em>Streptococcus</em> (GBS), is an increasingly concerning pathogen affecting humans and animals, including aquatic species. This bacterium significantly impacts aquaculture, causing disease outbreaks in various freshwater and marine fish, particularly in warm-water environments. This study examined the biological impact of two major virulence factors of <em>S. agalactiae</em> 1a and their roles in host pathogenesis. We attenuated a strain of <em>S. agalactiae</em> 1a (NAM) through targeted deletions of selected virulence genes, <em>cpsE</em> and <em>cylE,</em> involved in capsule formation and hemolysin production, respectively. <em>In vitro</em> experiments showed that the Δ<em>cpsE</em> strain lost antibody agglutination properties, whereas the Δ<em>cylE</em> strain lost the ability to lyse red blood cells. <em>In vivo</em> studies in Nile tilapia revealed reduced virulence of these mutant strains, with the double mutant (Δ<em>cylE</em>/Δ<em>cpsE</em>) showing the highest degree of attenuation, followed by the single capsule-deficient (Δ<em>cpsE</em>) and hemolysin-deficient (Δ<em>cylE</em>) strains. The brain appeared to be the primary site of bacterial establishment in fish challenged with viable bacteria. Unlike the wild-type strain, the capsule appeared to be a key component in localization, as capsule-deficient bacteria did not colonize the brain or spleen 10 days post-challenge. Deleting the <em>cpsE</em> gene completely prevented capsule formation, whereas deleting the <em>cylE</em> gene inhibited the hemolysin synthesis. The capsule proved to be a more potent virulence factor than hemolysin, with an additive attenuation effect in the double-mutant strain. These findings suggest that inhibiting hemolysin synthesis and capsule formation by gene deletion attenuates <em>S. agalactiae</em> 1a, reducing its virulence, and provide a basis for the development of a live-attenuated vaccine against the corresponding infection.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"170 ","pages":"Article 111097"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923759","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":"Genomic selection accelerates genetic improvement of tolerance to visceral nodular disease in the half-smooth tongue sole (Cynoglossus semilaevis)","authors":"Mengyang Chang ,&nbsp;Kunpeng Shi ,&nbsp;Jibin Shen ,&nbsp;Yu Yang ,&nbsp;Yishuai Li ,&nbsp;Jiayu Cheng ,&nbsp;Xiangming Cheng ,&nbsp;Yingming Yang ,&nbsp;Zhongkai Cui ,&nbsp;Songlin Chen ,&nbsp;Zhenxia Sha","doi":"10.1016/j.fsi.2026.111115","DOIUrl":"10.1016/j.fsi.2026.111115","url":null,"abstract":"<div><div>The half-smooth tongue sole (<em>Cynoglossus semilaevis</em>) is an economically important marine fish in China, but its vulnerability to visceral nodular disease (VND) caused by <em>Mycobacterium marinum</em> poses a significant threat to aquaculture. Based on traditional breeding methods, it is slowly to improve disease tolerance and then may lead to inbreeding depression. This study aimed to accelerate the development of VND-tolerant strains of <em>C. semilaevis</em> through genomic selection (GS). In this study, individuals from both reference and candidate populations were genotyped, and more than 7 million high-quality SNPs were identified by whole genome sequencing (WGS). Heritability estimates for VND tolerance, based on binary survival status and survival time, were 0.37 and 0.39, respectively, indicating moderate genetic control. To improve breeding efficiency, six GS models (Bayes A, Bayes B, BayesCpi, ssGBLUP, GBLUP, and rrBLUP) were evaluated, of which GBLUP showed the highest prediction accuracy (0.4925 for binary state and 0.5477 for survival time). Furthermore,the effect of SNP density on genomic prediction accuracy was investigated and it was found that 40K SNPs, selected via GWAS, provided the most reliable predictions. Through the GBLUP model with 40K SNPs, genomic estimated breeding values (GEBVs) were estimated for the candidate population and top 20 % was selected for breeding. Progeny from these selected individuals showed significantly higher survival rates in response to VND challenge, with 19.7 % increase compared to the control group, and these results confirmed the effectiveness of GS in enhancing disease tolerance. This study provides a promising approach to developing VND-tolerant <em>C. semilaevis</em>, which could significantly improve the sustainability of aquaculture.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"170 ","pages":"Article 111115"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923760","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":"Sulforaphane attenuates HFD-induced enteritis in yellow river carp by restoring immune homeostasis, repairing intestinal barrier, and modulating gut microbiota","authors":"Lu Wang ,&nbsp;Bingke Wang ,&nbsp;Jiaxiang Zhu ,&nbsp;Qi Zhang ,&nbsp;Yuxuan Cui ,&nbsp;Huajuan Shi ,&nbsp;Chunnuan Zhang","doi":"10.1016/j.fsi.2026.111125","DOIUrl":"10.1016/j.fsi.2026.111125","url":null,"abstract":"<div><div>High-fat diets (HFD) exacerbate intestinal health risks in aquaculture. This study evaluated effects of dietary sulforaphane (SFN) supplementation on intestinal morphology, biochemistry, microbiota, and metabolism in Yellow River carp (<em>Cyprinus carpio haematopterus</em>) fed HFD. Five isoprotein diets diets were formulated: control (CN, 6 % lipid), HFD (12.29 % lipid), and HFD with 10 (HS10), 15 (HS15), or 20 (HS20) mg/kg SFN. Results demonstrated that HFD induced marked intestinal inflammation featuring villi deformation, oxidative stress, epithelial exfoliation, mitochondrial swelling, significantly elevated pro-inflammatory cytokines (<em>TNF-α/IL-1β/IL-6</em>; <em>p</em> &lt; 0.05), and downregulated tight junction protein genes (<em>Occludin/ZO-1/Claudin-3</em>; <em>p</em> &lt; 0.05), concomitant with microbial dysbiosis (Proteobacteria dominance&gt;70 %, reduced <em>Cetobacterium</em>) and disrupted metabolic pathways (amino acid imbalance). SFN supplementation significantly enhanced antioxidant enzyme activities (SOD/CAT/GSH-Px, <em>p</em> &lt; 0.05), peaking in HS15, which also exhibited minimized pro-inflammatory cytokines and maximized tight junction expression (<em>p</em> &lt; 0.05). Furthermore, 16S rRNA gene sequencing of the gut microbiota indicated that SFN restored microbial homeostasis, notably by increasing the abundance of <em>Cetobacterium</em>. Metabolomic analysis based on KEGG enrichment revealed that these beneficial effects were associated with the activation of FoxO signaling, enhanced lysosomal function, and upregulation of coenzyme A biosynthesis. Critically, HS15 demonstrated optimal efficacy across all parameters. Therefore, 15 mg/kg SFN is identified as the optimal dose to ameliorate intestinal health in Yellow River carp, providing a theoretical basis for functional aquafeed development.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"170 ","pages":"Article 111125"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146017896","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":"Recent advances in vaccination strategies against acute hepatopancreatic necrosis disease (AHPND) in shrimp for sustainable aquaculture industry: A comprehensive review","authors":"Tijani Isa ,&nbsp;Riyanto Teguh Widodo ,&nbsp;Suzita Mohd Noor ,&nbsp;Nur Asyura Nor Amdan ,&nbsp;Zulhisyam Abdul Kari ,&nbsp;Norhidayah Mohd Taufek ,&nbsp;Fathiah Mohamed Zuki ,&nbsp;Alias Abdullah ,&nbsp;Subha Bhassu ,&nbsp;Zarif Mohamed Sofian ,&nbsp;Sagir Mustapha ,&nbsp;Didi Erwandi Mohamad Haron ,&nbsp;Ahmad Khusairi Azemi ,&nbsp;Muhammad Luqman Nordin","doi":"10.1016/j.fsi.2026.111136","DOIUrl":"10.1016/j.fsi.2026.111136","url":null,"abstract":"<div><div>Shrimp farming represents one of the most economically vital branches of aquaculture, significantly contributing to global food security and livelihoods, especially in Asia and Latin America. Countries such as China, Thailand, Vietnam, Indonesia, Malaysia, India, and Bangladesh are major producers, with <em>LitoPenaeus vannamei</em> and <em>Penaeus monodon</em> accounting for over 90 % of global shrimp production. Despite its economic value, the industry faces persistent threats from disease outbreaks, notably acute hepatopancreatic necrosis disease (AHPND). Antibiotic use, once common for disease control, is now restricted due to risks of resistance and environmental harm. Vaccination has emerged as a promising alternative, focusing on stimulating shrimp's innate immunity through DNA vaccines, recombinant subunit vaccines, live-attenuated, and whole cell-inactivated methods. Field and laboratory trials have shown promising results, including high levels of protection, improved survival rates, and increased expression of immune-related genes. Despite these advances, challenges persist, such as limited immune responses in juvenile shrimp, the absence of standardized immune markers, antigen degradation during oral delivery, and genetic diversity among <em>V. parahaemolyticus</em> strains. Continued research in shrimp immune mechanisms, antigen selection, and vaccine formulation is crucial to develop effective, scalable, and economically feasible vaccines for effective and sustainable AHPND prevention. This review highlights current vaccine strategies, field trial outcomes, challenges, and future directions, underscoring the potential of vaccination in integrated AHPND control for sustainable shrimp aquaculture.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"170 ","pages":"Article 111136"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146003213","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":"Combined histopathological, immunoenzymatic and transcriptomic analyses reveal the immune response mechanisms of silver pomfret infected by Vibrio parahaemolyticus","authors":"Dianyang Zhou ,&nbsp;Ping Han ,&nbsp;Yadong Xue ,&nbsp;Zhennan Sun ,&nbsp;Longdi Wang ,&nbsp;Xiumei Liu ,&nbsp;Jianming Chen ,&nbsp;Yajun Wang ,&nbsp;Suming Zhou ,&nbsp;Xue Sun ,&nbsp;Xinxin Du ,&nbsp;Xubo Wang","doi":"10.1016/j.fsi.2026.111124","DOIUrl":"10.1016/j.fsi.2026.111124","url":null,"abstract":"<div><div>The silver pomfret (<em>Pampus argenteus</em>), a vital aquaculture species, is highly susceptible to <em>Vibrio parahaemolyticus</em> infections, yet the molecular mechanisms underlying its immune response remain poorly understood. This study investigated gill responses to <em>V. parahaemolyticus</em> infection via intraperitoneal injection, analyzing histopathological, transcriptomic, and enzymatic changes at 3, 6, 12, 24 and 48 h post-infection (hpi). Histological analysis revealed progressive gill damage, with significant architectural disruption from 6 hpi and severe lesions by 48 hpi. Transcriptome profiling of 18 cDNA libraries generated 40–67 million clean reads, yielding 4492–5231 differentially expressed genes (DEGs) across time points, with 1094–2174 unique DEGs per time point. Inflammatory cytokines (<em>tnf-α</em>, <em>il-1β</em>, <em>il-8</em>, <em>il-12</em>) showed robust upregulation, peaking at 6–24 hpi, indicative of an active immune response. Gene Ontology (GO) and KEGG analyses identified enriched pathways, including “oxidative phosphorylation” (3–48 hpi) and “tight junction” (24 hpi), with “oxidoreductase activity” and “aerobic respiration” as the dominant functional categories. Oxidative stress markers (MDA, SOD, CAT, POD) exhibited time-dependent increases, reflecting enhanced antioxidant defenses. Weighted Gene Co-expression Network Analysis (WGCNA) revealed the turquoise module as being strongly correlated with infection, identifying hub genes (<em>gapdh</em>, <em>gapdhs</em>, <em>pgam2</em>, <em>g6pd</em>, <em>taldo1</em>, <em>pgam1a</em>) critical to immune regulation. This study is the first to systematically investigate the temporal crosstalk between inflammatory responses, oxidative stress, and metabolic reprogramming in silver pomfret gills during <em>V. parahaemolyticus</em> infection, providing novel molecular targets for the control of vibriosis.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"170 ","pages":"Article 111124"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974591","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":"Activation of the Nrf2-Keap1 pathway is associated with NAC-mediated alleviation of nitrite-induced oxidative and endoplasmic reticulum stress and apoptosis in Marsupenaeus japonicus","authors":"Yexin Lei,&nbsp;Rui Xu,&nbsp;Jinlong Zhan,&nbsp;Jianyong Liu","doi":"10.1016/j.fsi.2026.111114","DOIUrl":"10.1016/j.fsi.2026.111114","url":null,"abstract":"<div><div>Nitrite accumulation poses a serious threat to aquatic animals in intensive aquaculture systems. Although the antioxidant role of the Nrf2-Keap1 pathway is well established, its regulatory mechanisms under nitrite stress in crustaceans remain poorly understood. This investigation focused on the protective impact of N-acetylcysteine (NAC) on <em>Marsupenaeus japonicus</em> exposed to nitrite toxicity. Shrimp were injected with NAC or PBS and then exposed to 100 mg/L of nitrite nitrogen for 72 h. The findings revealed that pretreatment with NAC markedly reduced tissue damage in both the hepatopancreas and gills, in comparison to the PBS control group. Additionally, the NAC-treated <em>M. japonicus</em> exhibited upregulated mRNA levels of <em>Nrf2</em> and its associated antioxidant genes including <em>NQO1</em>, <em>HO-1</em>, <em>CAT</em>, <em>GPx</em>, <em>GST</em>, and <em>SOD</em>, while <em>Keap1</em> expression was notably suppressed. Additionally, the NAC group downregulated endoplasmic reticulum stress (ERS)-related genes (<em>PERK</em>, <em>eIF2α</em>, <em>ATF4</em>, <em>GRP78</em>, <em>CHOP</em>, <em>IRE1</em>, <em>XBP1</em>, <em>ATF6</em>) and apoptosis-related genes (<em>Caspase-3</em>, <em>Caspase-9</em>, <em>p53</em>, <em>Bax</em>, <em>Apaf-1</em>), while upregulating <em>Bcl-2</em>. Additionally, the NAC group improved total antioxidant capacity (T-AOC) and SOD activity, reduced malondialdehyde (MDA) content and Caspase-3 activity, and decreased the apoptosis rate in the hepatopancreas. The results indicate that NAC alleviates oxidative stress, ERS, and apoptosis triggered by nitrite in <em>M. japonicus</em>. This protective effect is associated with the activation of the Nrf2-Keap1 signaling pathway, suggesting its potential as a therapeutic strategy for nitrite toxicity in crustacean aquaculture.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"170 ","pages":"Article 111114"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923758","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":"Carbapenem-resistant Klebsiella pneumoniae exacerbates virulence through oxidative stress, apoptosis induction and gut microbiota dysbiosis in zebrafish models","authors":"Zhining Mo ,&nbsp;Jiajie Liu ,&nbsp;Yunhong Yi ,&nbsp;Mei Li ,&nbsp;Xiaosong Yang ,&nbsp;Gongqing Wu","doi":"10.1016/j.fsi.2026.111101","DOIUrl":"10.1016/j.fsi.2026.111101","url":null,"abstract":"<div><div>Carbapenem-resistant <em>Klebsiella pneumoniae</em> (CRKP), as a critical nosocomial pathogen, has emerged as a major global public health challenge due to its multidrug resistance and enhanced pathogenicity. This study systematically elucidated the virulence characteristics of CRKP and its host interaction mechanisms by comparing CRKP (ST258, <em>blaKPC</em>-positive) with carbapenem-susceptible <em>K. pneumoniae</em> (CSKP, ST86) in zebrafish infection models. We established dual infection models (adult intraperitoneal injection and larval immersion), revealing that ST258 CRKP strain exhibited significantly enhanced virulence: its median lethal dose (LD₅₀) was 7.3-fold lower than ST86 CSKP strain, with persistent proliferation in liver and intestinal tissues causing more severe histopathological damage. Mechanistic studies demonstrated that CRKP infection induced stronger oxidative stress and more pronounced apoptosis. 16S rRNA sequencing revealed CRKP-specific gut microbiota dysbiosis: a 147 % increase in <em>Klebsiella</em> abundance with significant depletion of protective <em>Faecalibacterium</em> and <em>Cetobacterium</em>, whereas CSKP infection primarily promoted <em>Aeromonas</em> and <em>Citrobacter</em> proliferation. Functional prediction analysis further identified CRKP-specific activation of drug metabolism pathways (e.g., cytochrome P450) and disruption of amino acid metabolism (e.g., suppressed cysteine/methionine pathways), which were closely associated with impaired host antioxidant defenses. This study provides zebrafish model evidence that the ST258 CRKP strain enhances pathogenicity through multiple mechanisms compared to the ST86 CSKP strain: enhanced tissue invasiveness, induction of oxidative stress and apoptosis, and disruption of gut microbial homeostasis. These findings offer novel insights into the pathogenesis of this high-risk CRKP clone and inform the development of microbiota-targeted therapeutic strategies against drug-resistant infections.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"170 ","pages":"Article 111101"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145917180","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}