Journal of fish diseases最新文献

{"title":"Serum and Tissue Kinetics of Oxolinic Acid in Black Rockfish (Sebastes schlegelii) Following a Single Oral Administration at Two Temperatures","authors":"Jun Sung Bae,&nbsp;Chae Won Lee,&nbsp;Chan Yeong Yang,&nbsp;Eun Ha Jeong,&nbsp;Jung Soo Seo,&nbsp;Mun-Gyeong Kwon,&nbsp;Ji-Hoon Lee","doi":"10.1111/jfd.14116","DOIUrl":"10.1111/jfd.14116","url":null,"abstract":"<div>\u0000 \u0000 <p>The objective of this study was to investigate the pharmacokinetic (PK) properties of oxolinic acid (OA) in black rockfish (<i>Sebastes schlegelii</i>) following a single oral administration of 30 mg/kg at 13°C and 22°C. Serum and tissue (muscle, liver and kidney) samples were collected at pre-determined time points and analysed using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). The results demonstrated that temperature significantly influenced the PK parameters of OA. The terminal half-life (t_1/2λz) was prolonged at 22°C across all tissues, while the total body clearance (CL/F) was reduced, suggesting a slower drug elimination at higher temperatures. The peak concentration (C_max) and the area under the concentration-time curve (AUC) values increased with temperature, indicating enhanced systemic exposure at 22°C. The volume of distribution (Vz/F) decreased from 13°C to 22°C, indicating reduced tissue distribution of OA at the higher temperature. PK/pharmacodynamic (PK/PD) analysis revealed that a single oral dose of 30 mg/kg was insufficient to achieve optimal antibacterial efficacy, implying that higher doses may be necessary. These findings highlight the necessity of temperature-adjusted dosing strategies for OA treatment in black rockfish aquaculture to optimise therapeutic efficacy while minimising antimicrobial resistance risks.</p>\u0000 </div>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":"48 7","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143710116","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":"Phenotypic and Genotypic Antimicrobial Resistance Profiles of Flavobacterium psychrophilum and Flavobacterium branchiophilum Isolated From Rainbow Trout (Oncorhynchus mykiss) in Slovenia","authors":"Katarina Pavlin,&nbsp;Bojan Papić,&nbsp;Irena Zdovc,&nbsp;Tanja Knific,&nbsp;Igor Gruntar,&nbsp;Rosvita Sitar,&nbsp;Diana Žele Vengušt,&nbsp;Marija Seničar,&nbsp;Matjaž Ocepek,&nbsp;Tanja Švara","doi":"10.1111/jfd.14119","DOIUrl":"10.1111/jfd.14119","url":null,"abstract":"<p><i>Flavobacterium psychrophilum</i> and <i>Flavobacterium branchiophilum</i> are important fish pathogens that cause considerable economic losses in freshwater aquaculture worldwide. Their antimicrobial resistance (AMR) profiles were evaluated using the latest Clinical and Laboratory Standards Institute broth microdilution method, which was adjusted for <i>F. branchiophilum</i> to achieve growth, and whole-genome sequencing (WGS). A total of 51 <i>F. psychrophilum</i> isolates and eight <i>F. branchiophilum</i> isolates from Slovenian farmed rainbow trout underwent phenotypic antimicrobial susceptibility testing. Overall, 86.3% of <i>F. psychrophilum</i> isolates were classified as non-wild-type (NWT) for oxytetracycline and enrofloxacin, and 90.2% of isolates were NWT for oxolinic acid. In contrast, all isolates tested were classified as wild-type (WT) for florfenicol and erythromycin. It was not possible to classify <i>F. branchiophilum</i> isolates as WT or NWT for the antimicrobials tested. A subset of <i>F. psychrophilum</i> (<i>n</i> = 7) and <i>F. branchiophilum</i> (<i>n</i> = 2) isolates was further characterised using WGS to investigate the mechanisms mediating antimicrobial resistance. In <i>F. psychrophilum</i>, the T83A or T83V substitution in GyrA was associated with reduced susceptibility to oxolinic acid. No other AMR genes or AMR-associated mutations were detected.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":"48 7","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jfd.14119","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143692249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Survey on Kudoa thyrsites in Sardina pilchardus From the Central Tyrrhenian Sea","authors":"Paolo Cipriani,&nbsp;Marialetizia Palomba,&nbsp;Luca Ruggiero,&nbsp;Stig Mæle,&nbsp;Lucilla Giulietti","doi":"10.1111/jfd.14123","DOIUrl":"10.1111/jfd.14123","url":null,"abstract":"&lt;p&gt;&lt;i&gt;Kudoa&lt;/i&gt; species are microscopic endoparasites of marine and estuarine fish with a global distribution (reviewed by Levsen &lt;span&gt;2015&lt;/span&gt;). The life cycle of &lt;i&gt;Kudoa&lt;/i&gt; remains unknown, but it is believed to follow a two-host cycle involving fish and an alternate host, likely a polychaete (Eszterbauer et al. &lt;span&gt;2015&lt;/span&gt;, Rangel et al. &lt;span&gt;2016&lt;/span&gt;). Some species can affect the quality of fish fillets by producing macroscopic cysts or post-mortem myoliquefaction, commonly referred to as ‘soft flesh’ condition (see reviews by Levsen &lt;span&gt;2015&lt;/span&gt;; Moran, Whitaker and Kent &lt;span&gt;1999&lt;/span&gt;). &lt;i&gt;Kudoa thyrsites&lt;/i&gt; is a well-known ‘soft flesh’-inducing species that infects the skeletal muscle of several teleost fishes worldwide, including commercially important wild species such as Atlantic mackerel (&lt;i&gt;Scomber scombrus&lt;/i&gt;), Atlantic cod (&lt;i&gt;Gadus morhua&lt;/i&gt;), mahi mahi (&lt;i&gt;Coryphena hippurus&lt;/i&gt;) and small pelagics (reviewed by Henning, Hoffman, and Manley &lt;span&gt;2013&lt;/span&gt;, and Levsen &lt;span&gt;2015&lt;/span&gt;; Giulietti et al. &lt;span&gt;2024a&lt;/span&gt;, &lt;span&gt;2024b&lt;/span&gt;, &lt;span&gt;2024c&lt;/span&gt;). ‘Soft flesh’ develops only in heavily infected fish with high parasite densities (Giulietti et al. &lt;span&gt;2022&lt;/span&gt;; St-Hilaire et al. &lt;span&gt;1997a&lt;/span&gt;).&lt;/p&gt;&lt;p&gt;European sardine (&lt;i&gt;Sardina pilchardus&lt;/i&gt;) is a clupeid pelagic fish distributed across the Eastern Atlantic Ocean from Senegal to the North Sea and throughout the Mediterranean Sea (Jemaa et al. &lt;span&gt;2015&lt;/span&gt;; Parrish, Serra and Grant &lt;span&gt;1989&lt;/span&gt;; Silva et al. &lt;span&gt;2015&lt;/span&gt;). Sardines are among the most commercially important species in the Mediterranean, caught using purse seines and pelagic trawls, and play a significant role in traditional cuisine (FAO &lt;span&gt;2023&lt;/span&gt;). In the Northeast (NE) Atlantic, cases of ‘soft flesh’ in sardines have been linked to &lt;i&gt;K. thyrsites&lt;/i&gt; infections. The first documented case occurred in the 1990s in Portuguese waters, causing significant economic losses to the canning industry (Menezes et al. &lt;span&gt;1990&lt;/span&gt;). Subsequent infections with &lt;i&gt;K. thyrsites&lt;/i&gt; and associated ‘soft flesh’ have been reported in several sardine stocks, including the Iberian stock from Portugal and northern Spain, and the Northern African stock from Moroccan Atlantic waters (Cruz, Silva, and Saraiva &lt;span&gt;2011&lt;/span&gt;; Iglesias et al. &lt;span&gt;2022&lt;/span&gt;; Gilman and Eiras &lt;span&gt;1998&lt;/span&gt;; Giulietti et al. &lt;span&gt;2024b&lt;/span&gt;, &lt;span&gt;2024c&lt;/span&gt;). In contrast, little is known about &lt;i&gt;K. thyrsites&lt;/i&gt; infections in sardines from the Mediterranean Sea. &lt;i&gt;K. thyrsites&lt;/i&gt; has been identified as the causative agent of ‘soft flesh’ in two specimens of silver scabbardfish (&lt;i&gt;Lepidopus caudatus&lt;/i&gt;) from the Alboran Sea (Giulietti et al. &lt;span&gt;2019&lt;/span&gt;) and in one specimen of Atlantic bonito (&lt;i&gt;Sarda sarda&lt;/i&gt;) from the western Mediterranean (Panebianco et al. &lt;span&gt;2024&lt;/span&gt;). Moreover, a case of ‘soft flesh’ caused by an unidentified &lt;i&gt;Kudoa&lt;/i&gt; s","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":"48 7","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jfd.14123","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143692250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Review of In Silico Approaches for Discovering Natural Viral Protein Inhibitors in Aquaculture Disease Control","authors":"Luu Tang Phuc Khang,&nbsp;Nguyen Dinh-Hung,&nbsp;Sk Injamamul Islam,&nbsp;Sefti Heza Dwinanti,&nbsp;Samuel Mwakisha Mwamburi,&nbsp;Patima Permpoonpattana,&nbsp;Nguyen Vu Linh","doi":"10.1111/jfd.14120","DOIUrl":"10.1111/jfd.14120","url":null,"abstract":"<div>\u0000 \u0000 <p>Viral diseases pose a significant threat to the sustainability of global aquaculture, causing economic losses and compromising food security. Traditional control methods often demonstrate limited effectiveness, highlighting the need for alternative approaches. The integration of computational methods for the discovery of natural compounds shows promise in developing antiviral treatments. This review critically explores how both traditional and advanced in silico computational techniques can efficiently identify natural compounds with potential inhibitory effects on key pathogenic proteins in major aquaculture pathogens. It highlights fundamental approaches, including structure-based and ligand-based drug design, high-throughput virtual screening, molecular docking, and absorption, distribution, metabolism, excretion and toxicity (ADMET) profiling. Molecular dynamics simulations can serve as a comprehensive framework for understanding the molecular interactions and stability of candidate drugs in an in silico approach, reducing the need for extensive wet-lab experiments and providing valuable insights for targeted therapeutic development. The review covers the entire process, from the initial computational screening of promising candidates to their subsequent experimental validation. It also proposes integrating computational tools with traditional screening methods to enhance the efficiency of antiviral drug discovery in aquaculture. Finally, we explore future perspectives, particularly the potential of artificial intelligence and multi-omics approaches. These innovative technologies can significantly accelerate the identification and optimisation of natural antivirals, contributing to sustainable disease management in aquaculture.</p>\u0000 </div>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":"48 7","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143663519","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":"Malignant Mixed Irido-Melanophoroma in a Betta splendens with Concurrent Mycobacterium chelonae Isolation—A Case Report","authors":"Zi An Yu,&nbsp;Lorraine A. Corriveau,&nbsp;Joanne B. Messick","doi":"10.1111/jfd.14115","DOIUrl":"10.1111/jfd.14115","url":null,"abstract":"<p>A 10-month-old intact male blue Siamese fighting fish (<i>Betta splendens</i>) was presented to the Purdue University Small Animal Hospital with multiple bilateral masses on the caudal flank. Comprehensive evaluation using impression cytology, histopathology and transmission electron microscopy (TEM) revealed a tumour composed of a mixed-cell population of iridophores and melanophores, consistent with a mixed-cell irido-melanophoroma. The tumour exhibited clinical and cytohistological characteristics of malignancy, including rapid enlargement, cellular and nuclear atypia, tissue invasion and tumour emboli formation. Interestingly, mild mononuclear inflammation was observed, and mycobacterial culture isolated an acid-fast-positive bacterium identified as <i>Mycobacterium chelonae</i> through Sanger sequencing of <i>rpoB</i> and <i>16S rRNA</i>, combined with Basic Local Alignment Search Tool analysis. This is the first case report of a malignant piscine chromatophoroma with concurrent inflammation and isolation of <i>Mycobacterium</i>, highlighting the need for further studies to investigate a potential association.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":"48 7","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jfd.14115","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143657499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid Detection of Aeromonas veronii Using GGDEF Gene-Based Colorimetric Loop-Mediated Isothermal Amplification","authors":"Tien Tien Vicky Lau,&nbsp;Suat Moi Puah,&nbsp;Kek Heng Chua","doi":"10.1111/jfd.14112","DOIUrl":"10.1111/jfd.14112","url":null,"abstract":"<div>\u0000 \u0000 <p><i>Aeromonas veronii</i> has emerged as an important fish pathogen that poses threats to the aquaculture industry worldwide, and rapid detection is essential to minimise negative economic impact. In this study, a colorimetric loop-mediated isothermal amplification (LAMP) assay was developed to rapidly detect <i>A. veronii</i>, targeting a gene encoding GGDEF domain-containing diguanylate cyclase. The entire LAMP reaction could be completed in 30 min at 65°C based on colour change from pink to yellow. In addition, the assay demonstrated 100% specificity with no cross reaction with other common fish pathogens. The detection limit (LOD) was 500 pg/μL using purified plasmid and 1.72 × 10⁵ cfu/mL (equivalent to 1.72 × 10² cfu/reaction) using crude genomic DNA extracted from the pure culture of <i>A. veronii</i> ATCC 9071. LAMP demonstrated comparable performance to conventional PCR using 57 bacterial isolates, with 100% (20/20) specificity, 91.9% (34/37) sensitivity, 94.7% (54/57) accuracy and a 0.888 Cohen's kappa value. Lastly, the LOD of LAMP in a spiked water sample was 1.72 × 10⁵ cfu/mL (equivalent to 3.44 × 10³ cfu/reaction). Overall, our LAMP assay has a high level of diagnostic agreement with conventional PCR and can be used as a valuable tool for the rapid detection of <i>A. veronii</i> from environmental samples.</p>\u0000 </div>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":"48 7","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143605163","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":"Use of Biomarkers in Plasma and Faeces to Evaluate Physiological Status of Atlantic Salmon (Salmo salar L.) During Salmonid Alphavirus Infection","authors":"Eirik Hoel,&nbsp;Frederike Keitel-Gröner,&nbsp;Christina Aspaas Husebø,&nbsp;David Lausten Knudsen,&nbsp;Julia Mullins,&nbsp;Christian Wallace,&nbsp;Hanne Log Persson,&nbsp;Hanna S. Bjerke-Ertenstein,&nbsp;Maren Iden Bjerkeset,&nbsp;Kjetil Berge","doi":"10.1111/jfd.14114","DOIUrl":"10.1111/jfd.14114","url":null,"abstract":"<div>\u0000 \u0000 <p>Salmonid alphavirus (SAV) is the causative agent of pancreas disease (PD), a disease that can cause severe implications for marine farming of Atlantic salmon. This study examines physiological changes in Atlantic salmon during SAV infection through a controlled trial and two field trials. In the controlled trial, plasma creatine kinase (CK), alanine aminotransferase (ALAT) and aspartate aminotransferase (ASAT) levels increased significantly 4 weeks post challenge, peaked at 8 weeks and by 12 weeks, ALAT levels returned to pre-challenge levels, while CK and ASAT remained elevated. Weekly mortality peaked at 4.1% in week 5, and there was an 89% reduction in appetite in week 4 post challenge. In two field trials in southern Norway, SAV3 was detected in spring/early summer by reverse transcription quantitative polymerase chain reaction (RT-qPCR). As SAV prevalence increased, plasma CK, ALAT, ASAT and lactate dehydrogenase (LDH) levels peaked, along with the stress markers cortisol and tetrahydrocortisone in faeces. Despite low mortality (&lt; 0.2% weekly), a decrease in appetite was observed in both field trials. Understanding the physiological status of the fish through monitoring tools like RT-qPCR, blood chemistry and stress markers provides a foundation for implementing mitigation measures such as stress reduction, timed harvest or clinical nutrition at the onset of pancreas disease.</p>\u0000 </div>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":"48 7","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143567030","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":"Identification and Pathogenicity of Lactococcus Species in Nile Tilapia (Oreochromis niloticus) and Asian Sea Bass (Lates calcarifer)","authors":"Janchai Wongkaew,&nbsp;Satid Chatchaiphan,&nbsp;Suwimon Taengphu,&nbsp;Ha Thanh Dong,&nbsp;Saengchan Senapin,&nbsp;Sanit Piyapattanakorn","doi":"10.1111/jfd.14113","DOIUrl":"10.1111/jfd.14113","url":null,"abstract":"<div>\u0000 \u0000 <p>Lactococcosis, primarily caused by <i>Lactococcus garvieae</i>, is prevalent in various freshwater fish species globally. Yet, its significance in Thai fish aquaculture remains poorly understood. This study investigated Lactococcosis-associated diseases across four red tilapia (<i>Oreochromis</i> sp.) and one Asian sea bass (<i>Lates calcarifer</i>) farm in Thailand in 2022. Chronically diseased fish displaying clinical signs such as exophthalmia or corneal opacity, erratic swimming, scale loss and skin haemorrhage, as well as apparently healthy specimens, were studied. Bacterial isolation was performed from the fish internal organs. Gram-positive bacterial isolates were selected and later identified as <i>L. lactis</i> (<i>n</i> = 4), <i>L. taiwanensis</i> (<i>n</i> = 1), <i>L. garvieae</i> (<i>n</i> = 2) and <i>L. petauri</i> (<i>n</i> = 2) based on bacterial 16S rDNA and <i>gyrB</i> partial sequences. Sub-adults of Nile tilapia were intracoelomic (IC) injected with representatives of each of the three <i>Lactococcus</i> species (<i>L. garvieae</i>, <i>L. lactis</i> and <i>L. taiwanensis</i>) at varying doses (10³–10⁷ CFU/fish), while juvenile Asian sea bass were IC injected with <i>L. petauri</i> at doses ranging from 10² to 10⁸ CFU/fish. Control groups received culture medium alone. By the end of the 21-day test, mortality rates from all challenge groups ranged from 0% to 14.82%. Some clinical signs were observed in groups challenged with higher doses of the bacteria. Enzyme-linked immunosorbent assay (ELISA) showed that survivor fish exposed to high bacterial doses elicited specific antibodies IgM. In summary, this study identifies the presence of <i>Lactococcus</i> species in farmed fishes, which exhibit low virulence in Nile tilapia and Asian sea bass under laboratory-controlled challenges. These bacterial isolates appear to be opportunistic rather than pathogenic, potentially indicating underlying health challenges within the affected farms.</p>\u0000 </div>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":"48 7","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143542181","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 Investigation of Trichodinid Species (Ciliophora: Trichodinidae) on Farmed Hybrid Yellow Catfish (Tachysurus fulvidraco × Tachysurus vachelli) in China.","authors":"Enze Zhang, Hao Yang, Xiao Tu, Zemao Gu","doi":"10.1111/jfd.14100","DOIUrl":"https://doi.org/10.1111/jfd.14100","url":null,"abstract":"<p><p>Hybrid yellow catfish (Tachysurus fulvidraco♀ × Tachysurus vachelli♂) is a significant aquaculture variety in China. It is easy to be infected by trichodinids, causing serious economic losses. However, the species investigation of trichodinids on hybrid yellow catfish is relatively deficient, which seriously hinders the prevention and control of trichodiniasis. Hence, trichodinids were collected in a hybrid yellow catfish farm in Hubei Province from June 2022 to October 2023 and identified by morphological and molecular biology methods. A new species Tripartiella luhuensis sp. nov. and nine Trichodina species were described. Phylogenetic analyses demonstrated that T. luhuensis nested in the Trichodinella-Tripartiella-Paratrichodina clade, indicating that the genus Tripartiella is not a monophyletic group. Besides, Trichodinid species from Siluriformes hosts have relatively similar evolutionary positions. Histopathological analysis revealed that the parasitism of trichodinids caused mechanical damage and mucus hypersecretion to gill of the host. The present study reports trichodinid species on hybrid yellow catfish for the first time and adds one new species to the genus Tripartiella. We also indicate the importance of preventing and controlling trichodiniasis in hybrid yellow catfish farming.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":" ","pages":"e14100"},"PeriodicalIF":2.2,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143542178","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":"Immune Response of Nile Tilapia (Oreochromis niloticus) Vaccinated With Diatom-Based Oral Vaccines Against Piscine Francisellosis","authors":"Collin Meyer,&nbsp;Roshan P. Shrestha,&nbsp;Ruth Milston-Clements,&nbsp;Sarah Gibson,&nbsp;Taylor I. Heckman,&nbsp;Zeinab Yazdi,&nbsp;Esteban Soto","doi":"10.1111/jfd.14111","DOIUrl":"10.1111/jfd.14111","url":null,"abstract":"<p>Piscine francisellosis is a highly infectious and economically significant disease caused by <i>Francisella orientalis</i> in tilapia (<i>Oreochromis</i> spp.). There are currently no approved treatments or commercial vaccines for this disease in cultured fish. Injectable vaccines using diatoms as antigen expression vectors have demonstrated efficacy in tilapia models; however, no oral vaccine trials have been performed. We hypothesised that fusion proteins consisting of <i>F. orientalis</i> IglC and flagellin expressed in <i>Thalassiosira pseudonana</i> diatoms will act as self-adjuvanting antigen delivery systems to confer a protective immune response against <i>F. orientalis</i> in tilapia when administered as top-coated feed. Different treatments were immunised and subsequently provided with one or two boosters prior to challenge. Fish were challenged with virulent <i>F. orientalis</i> via immersion thirty days post initial immunisation. Tilapia immune response was assessed 24 h post-challenge by quantifying <i>il-12, il-10, ifn-γ</i> and <i>tgf-β</i> gene expression in gills and internal organs. Morbidity and mortality were monitored for 21 days after challenge and bacterial load was assessed in survivors. Findings indicate significant changes in the expression of <i>ifn-γ</i> and <i>tgf-β</i> in immunised fish, but similar mortality rates and bacterial load across all exposed groups.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":"48 7","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jfd.14111","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143530945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}