Diseases of aquatic organisms最新文献

{"title":"Production and evaluation of a rabbit polyclonal antibody specific to the Aeromonas hydrophila outer membrane protein Omp38.","authors":"Tri Nguyen Do, Binh Nhu Nguyen, Tran Thi Tran, Trinh Thi Nguyen","doi":"10.3354/dao03914","DOIUrl":"https://doi.org/10.3354/dao03914","url":null,"abstract":"<p><p>The outer membrane protein Omp38 of Aeromonas hydrophila, a major fish pathogen, is a potential candidate for vaccine development. In this study, we produce a rabbit polyclonal antibody specific to this protein. Recombinant Omp38, expressed in E. coli cells, was used as an antigen for rabbit immunization. The obtained antiserum successfully recognized Omp38 in Western blot, ELISA, and immunofluorescence staining. The antiserum could detect Omp38 at concentrations of ≥0.1563 ng well-1 and showed an endpoint titer of 1:5120000. Antibodies were further purified from antiserum using Protein A chromatography, yielding over 95% purity. The purified antibody could detect Omp38 at concentrations as low as 0.0391 ng well-1 at the 1:10000 dilution and retained reactivity at the 1:10240000 dilution. Overall, this study successfully generated a rabbit antiserum and a purified polyclonal antibody sample against Omp38, which can be applied in future studies related to this protein.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"166 ","pages":"1-6"},"PeriodicalIF":1.2,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147834969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of Anguillicoloides crassus (Nematoda) and a survey of endohelminths of American eels in Georgia, USA.","authors":"Maggie A Young, Makala E Fabrizio, Vasyl V Tkach, Jim Page, Amory Cook, J Mike Kinsella, Florian B Reyda, Anindo Choudhury, Brandon W Baker, Tyler J Achatz","doi":"10.3354/dao03915","DOIUrl":"https://doi.org/10.3354/dao03915","url":null,"abstract":"<p><p>The American eel Anguilla rostrata is a catadromous fish with a unique life history; however, parasite surveys of these eels in the southeastern USA are limited. In this study, we surveyed the parasite fauna of 98 American eels collected from the Altamaha and Ocmulgee rivers in Georgia between January 2024 and August 2025. Eels were examined for external and internal parasites. The invasive, pathogenic swim bladder nematode Anguillicoloides crassus was detected in 62 of 98 eels (63.2% prevalence), with all infections occurring in the Altamaha River population. Infected eels harbored up to 21 nematodes, although most infections consisted of fewer than 5 individuals. No clear seasonal trends of infection were observed. The prevalence and mean intensity of A. crassus infections observed in Georgia were higher than those reported for most other regions along the US east coast. This study provides the first published record of A. crassus from Georgia and expands the known parasite diversity of American eels within the state. Our data also demonstrates the presence of 2 trematode genera, 3 cestode genera, 6 nematode genera, 3 acanthocephalan genera, and 1 arthropod genus. Many of these represent the first reports from eels in the state of Georgia.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"166 ","pages":"1-5"},"PeriodicalIF":1.2,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147835007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact and distribution of Perkinsus olsenii in cultivated Mediterranean mussel Mytilus galloprovincialis from the southern coast of Campania (Italy).","authors":"Francesca Carella, Lorenza D'Angelo, Laura Troise, Emanuela Di Lecce, Gianluigi Paduano, Maria Gabriella Lucibelli, Fabio Di Nocera","doi":"10.3354/dao03913","DOIUrl":"https://doi.org/10.3354/dao03913","url":null,"abstract":"<p><p>Following a previous description from the Campania region (southern Italy), a survey for perkinsosis was performed at 12 mussel farms along the Italian coast during the period October 2022 to July 2023. The prevalence of Perkinsus parasites was estimated by PCR using genus-specific primers. Seven farms tested positive and sequencing was performed to identify the Perkinsus species. The parasite Perkinsus olsenii was detected in the farm samples with a BLAST identity of 97-100%. One of the affected farms was also monitored for the period of July 2022-June 2023 using histopathology, Ray's fluid thioglycollate culture method, and quantitative PCR. The sensitivity of each of the techniques was also determined. Trophozoite stages were observed mostly aggregated in the connective tissue of the digestive tract and gonad/mantle, and to a lesser extent in the foot and kidney, producing an encapsulated inflammatory response that occupied most of the tissues in some samples. The condition index of affected individuals was lower than in healthy ones (p < 0.05) and larger animals (5.8-6 cm) were more often infected (p < 0.05). This study provides information regarding P. olsenii pathogen infections in M. galloprovincialis in the Campania region, its seasonal variations, and host-parasite interactions over a 1 year period.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"166 ","pages":"1-15"},"PeriodicalIF":1.2,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147835036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Infection dynamics of Batrachochytrium dendrobatidis in subtropical amphibian communities.","authors":"Camila F Moser, Wesley J Neely, Leigha M Stahl, Laura K Schuck, Henrique Schipanski, C Guilherme Becker, Pedro Peloso","doi":"10.3354/dao03911","DOIUrl":"https://doi.org/10.3354/dao03911","url":null,"abstract":"<p><p>Batrachochytrium dendrobatidis (Bd) is a pathogenic fungus causing population declines and extinctions of amphibians globally. Anthropogenic habitat alteration can directly and indirectly influence host-pathogen interactions by modifying wetland microclimates, physicochemical profiles, and amphibian communities. To test the combined effects of host-specific traits and environmental factors on Bd infection dynamics, we sampled 581 amphibians from 12 species in Tuscaloosa County, Alabama, USA. We tested the influence of host traits (body size and ecological behavioral habit) and environmental factors (habitat disturbance and water temperature) on Bd prevalence and infection loads, while body size was included in the models only as a covariate to control for potential effects on infection parameters. Bd was detected in 127 individuals (22% community prevalence) across 6 frog and 2 salamander species. Aquatic amphibians showed higher Bd prevalence and loads than terrestrial and arboreal species, with no significant differences between the latter 2 groups. Higher water temperatures were associated with lower Bd prevalence and loads, while body size and habitat disturbance were not important Bd predictors. These results emphasize the influence of host traits and environmental factors on Bd dynamics, expanding our understanding of amphibian host-pathogen interactions in an understudied region.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"166 ","pages":"1-12"},"PeriodicalIF":1.2,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147834980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Haplosporidium pinnae infection confirmed in Pinna nobilis populations in the Sea of Marmara.","authors":"Uğur Karadurmuş, Emre Turgay, Mert Gürkan, İbrahim Ender Künili, Selin Ertürk Gürkan, Mustafa Sarı","doi":"10.3354/dao03912","DOIUrl":"https://doi.org/10.3354/dao03912","url":null,"abstract":"<p><p>Fan mussels Pinna nobilis across the Mediterranean Sea have been severely impacted by a widespread mass mortality event, largely attributed to Haplosporidium pinnae. While the Sea of Marmara (SoM) has historically served as a refuge for this Critically Endangered species, recent findings suggest the emergence of various pathogens, including haplosporidian parasites, in SoM populations. This study presents the first confirmed case of H. pinnae infection in fan mussels from the southern SoM, with a focus on species-level identification, and contributes to growing concerns about the potential spread of this pathogen into previously unaffected regions. On 23 November 2024, 5 live fan mussels were collected from depths of 2.3-6.5 m in the southern SoM. Histopathological examination revealed structural alterations in the mantle tissue and the presence of plasmodial stages of H. pinnae. Molecular analyses further confirmed the presence of H. pinnae in several samples, exhibiting 100% sequence similarity with isolates from other Mediterranean regions. This study provides essential evidence of infection in the SoM and underscores the need for continued monitoring and conservation efforts for fan mussel populations in the region, especially as pathogens continue to spread across the Mediterranean Sea. The results represent a significant conservation alarm and highlight the urgent need for continued pathogen surveillance, early warning strategies, and robust management interventions in one of the last strongholds of this keystone species.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"166 ","pages":"1-6"},"PeriodicalIF":1.2,"publicationDate":"2026-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147765493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emerging pathogen Chryseobacterium sp. isolated from diseased goldfish Carassius auratus: antimicrobial susceptibility and pathology.","authors":"Rajamani Srinath, Arun Sudhagar, Arathi Dharmaratnam, Sagar Gorakh Satkar, Valaparambil Saidmuhammed Basheer","doi":"10.3354/dao03910","DOIUrl":"https://doi.org/10.3354/dao03910","url":null,"abstract":"<p><p>Chryseobacterium sp., belonging to the family Weeksellaceae, is an emerging fish pathogen that is opportunistic in nature. In this study, we investigated a clinically infected goldfish Carassius auratus from a fish farm during a disease outbreak. The bacterial colonies were isolated from the kidneys of infected goldfish. Following a 24 h incubation at 28°C, the colonies on nutrient agar exhibited yellow pigmentation and were identified as Gram-negative, rod-shaped, catalase-positive, and oxidase-positive. A total of 35 antibiotics belonging to different classes were used to determine the antibiotic susceptibility pattern of the isolated bacteria. Amplification and sequence analysis of the 16S rRNA gene identified the microorganism as Chryseobacterium sp., sharing 99.3% sequence similarity. The pathogenicity of this bacterial pathogen was experimentally confirmed in goldfish by a challenge experiment, and LD50 was determined as 7.46 × 107 CFU ml-1. Histopathological analysis of the infected fish revealed degeneration of renal tubule epithelium and melano-macrophagic aggregates with hyperaemic condition in the kidney. Similarly, infected gills exhibit primary and secondary lamellar hyperplasia, with lamellar oedema, necrosis and fusion of secondary lamella. This study underscores the virulence of Chryseobacterium sp. as a significant opportunistic pathogen in goldfish, highlighting the need for vigilant monitoring and intervention strategies to prevent outbreaks.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"166 ","pages":"1-12"},"PeriodicalIF":1.2,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147638324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emaciation and marine debris contribute to sperm whale Physeter macrocephalus strandings in southeastern USA: comparing 4 cases from 2020-2022.","authors":"Jennifer C G Bloodgood, Emily J Cramer, Carl S Cloyed, Michelle D Staudinger, Mackenzie L Russell, Ruth H Carmichael, Kathleen M Colegrove, David S Rotstein, Wayne E McFee, Nicole I Stacy, Lauren E Albrittain, Wendy B Marks, Jillian R Schwartz, Denise Boyd","doi":"10.3354/dao03909","DOIUrl":"10.3354/dao03909","url":null,"abstract":"<p><p>Large whale strandings along the east coast of the USA have increased in recent years, resulting in unusual mortality event (UME) declarations for several species. Endangered sperm whales Physeter macrocephalus have not been included in a UME; however, recent strandings have shown commonalities that warrant investigation. We analyzed 4 live-stranded sperm whales ('case' whales) in waters of the southeastern USA from 2020-2022 to determine if common factors contributed to death and to inform future management decisions. Thorough investigations were performed, including necropsy, histopathology, and infectious disease and biotoxin testing. Major findings were related to emaciation; there was no evidence of infectious disease or significant toxin exposure. Two of the whales had ingested fishing gear and other marine debris that may have contributed to emaciation. Prey identification and stable isotope analysis (SIA) of these whales combined with SIA of 4 additional sperm whales ('reference' whales) provided further life history data for this species. Prey consumed were primarily cephalopods from families consistent with known sperm whale diets in other parts of the world, and SIA suggested that case whales had similar foraging habitats and trophic levels compared to reference whales. The common finding of emaciation in case whales despite typical prey consumption emphasizes the need for continued research on factors that may influence foraging efficiency or prey availability and quality in this region. Furthermore, finding ingested fishing gear in 2 whales supports continued efforts to monitor and mitigate human impacts to support long-term survival and recovery of sperm whale populations.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"166 ","pages":"1-19"},"PeriodicalIF":1.2,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147638337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intestinal entamoebiasis in a captive colony of Anderson's crocodile newts Echinotriton andersoni.","authors":"Varvara Semenova, Nicholas A Buscaglia, Robert J Ossiboff","doi":"10.3354/dao03908","DOIUrl":"https://doi.org/10.3354/dao03908","url":null,"abstract":"<p><p>Entamoeba protozoa are known to cause enteric and sometimes systemic disease in both domestic and non-domestic animals. In amphibians, Entamoeba spp. are primarily documented as incidental gastrointestinal inhabitants, with rare reports of clinically significant entamoebiasis. In the last decade, mortality outbreaks caused by a recently described protozoan, Entamoeba sp. CT1, have been documented in free-ranging anurans in Australia and managed anurans in the USA associated with gastroenteritis and substantial morbidity and mortality. In 2023, a small population of Anderson's crocodile newts Echinotriton andersoni in managed care at a zoological institution experienced a disease outbreak resulting in the death or euthanasia of 4/13 (31%) newts over an approximately 1 mo period. Clinical signs included dehydration, poor skin quality, and lethargy. Postmortem examination of 3 newts revealed marked, proliferative, and necrotizing inflammation of the intestinal tract, urinary bladder, and cloaca with intramucosal amoebic protozoa. The gonadal ducts (2/3 newts) were also variably affected. Entamoeba PCR and Sanger sequencing of formalin-fixed paraffin-embedded intestinal tissue from all examined newts amplified DNA with 100% sequence identity to the recently identified Entamoeba sp. CT1. However, unlike reports of Entamoeba sp. CT1 in anurans, lesions in the crocodile newts were not restricted to the gastrointestinal tract. This is the first report of Entamoeba sp. CT1 causing significant clinical disease in caudates, emphasizing its importance as an amphibian pathogen with the potential to cause disease in managed and free-ranging amphibian populations.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"165 ","pages":"1-6"},"PeriodicalIF":1.2,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147510500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wild-type cutoff values for standard broth microdilution antimicrobial susceptibility testing of Edwardsiella ictaluri and E. piscicida isolates.","authors":"Charles M Gieseker, David A Simon, Destini Coiner, Brandy Malbrough, John P Hawke, Maria S Mitchell, Jay K Thornton, Patricia S Gaunt, Martha Pulido-Landinez, Lifang Yan, Melissa A West, Megan E Jacob, Matt J Griffin, Tina C Crosby, Elliott Kittel, Ron A Miller","doi":"10.3354/dao03907","DOIUrl":"https://doi.org/10.3354/dao03907","url":null,"abstract":"<p><p>Edwardsiella ictaluri and E. piscicida are bacterial pathogens that infect a variety of commercially important wild and cultured fish and cause significant economic losses among various farmed fish sectors, especially the catfish industries in the USA and Vietnam. The Clinical and Laboratory Standards Institute (CLSI) offers standard antimicrobial susceptibility testing (AST) methods for these pathogens and others, but internationally harmonized criteria, called epidemiological cutoff values (ECVs), are still needed to identify isolates with decreased antimicrobial susceptibility. To address this need, minimal inhibitory concentration (MIC) data for 9 antimicrobials were generated using the standard broth microdilution AST method at 28 ± 2°C for 44-48 h. The data sets comprise MICs from 101 E. ictaluri isolates from 4 independent laboratories and 115 E. piscicida isolates from 3 laboratories. Aggregated MIC distributions were used to calculate wild-type (WT) cutoff values for the 18 bacteria/antimicrobial combinations. WT cutoff values for E. ictaluri against ampicillin, enrofloxacin, erythromycin, florfenicol, gentamicin, oxolinic acid, oxytetracycline, ormetoprim/sulfadimethoxine, and trimethoprim/sulfamethoxazole were ≤1, ≤0.12, ≤128, ≤2, ≤2, ≤0.5, ≤2, ≤0.5/9.5, and ≤0.25/4.8 µg ml-1, respectively. WT cutoff values for E. piscicida were ≤8, ≤0.12, n/a, ≤2, ≤2, ≤0.25, ≤2, ≤0.12/2.4, and ≤0.12/2.4 µg ml-1, respectively. No E. piscicida WT cutoff value could be calculated for erythromycin. These WT cutoff values provided the CLSI with data needed to approve ECVs which will be included in the next edition of the VET04 supplement. CLSI-approved ECVs resulting from this work will greatly improve antimicrobial resistance surveillance of these bacterial pathogens impacting global aquaculture.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"165 ","pages":"1-10"},"PeriodicalIF":1.2,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147510479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Susceptibility to columnaris disease in Chinook salmon Oncorhynchus tshawytscha offspring from thiamine-deficient and thiamine-replete females.","authors":"Taylor N Abraham, Diem Thu Nguyen, Zeinab Yazdi, Heather N Bell, Anne E Todgham, Mark Adkison, Rachel C Johnson, Carson Jeffres, Scott Foott, Nann A Fangue, Mark Fast, Jacques Rinchard, Jarrod M Ludwig, Esteban Soto","doi":"10.3354/dao03903","DOIUrl":"10.3354/dao03903","url":null,"abstract":"<p><p>Nutrient deficiency can cause increased susceptibility to infectious diseases in fish, thus leading to high rates of morbidity and mortality. Thiamine deficiency complex (TDC) in fish can lead to low reproductive success and high mortality rates. Columnaris disease in salmonids, caused by Flavobacterium columnare, has resulted in devastating losses in aquaculture production and wild populations of Pacific salmon particularly associated with climate change and high water temperatures. There is growing awareness that both TDC and columnaris are emerging diseases of salmonids on the west coast of North America; however, it is unknown whether fish that survive from low/intermediate thiamine level eggs will experience latent mortality due to susceptibility to infectious diseases like columnaris. To investigate the interaction of TDC survivors and columnaris, Chinook salmon Oncorhynchus tshawytscha fry reared from either thiamine-deficient (n = 120) or thiamine-replete (n = 120) eggs were challenged with F. columnare using an immersion challenge model of infection, and morbidity/mortality, immune responses, and bacterial load were evaluated. The cumulative mortalities between the treatment groups were significantly different, with the thiamine-deficient, F. columnare-exposed fry ending the challenge with an 80.3% survival rate and the thiamine-replete, F. columnare-exposed fry ending with a 29.03% survival rate (p < 0.0001). Different transcript abundance was detected in gills and spleen of thiamine-deficient and thiamine-replete fry exposed to F. columnare. This study demonstrated that fry reared from eggs low in thiamine have an altered immune response and warrants further studies to better understand interaction with potential pathogens at different life stages.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"165 ","pages":"1-11"},"PeriodicalIF":1.2,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147431495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}