Journal of fish diseases最新文献

{"title":"Immune response and protection efficacy of formalin-killed vaccines against Streptococcus iniae in four-finger threadfin Eleutheronema tetradactylum","authors":"Yin-Ze Shi,&nbsp;Andre Giovanni,&nbsp;Li-Wu Cheng,&nbsp;Wen-Rou Huang,&nbsp;Pei-Chi Wang,&nbsp;Shih-Chu Chen","doi":"10.1111/jfd.14009","DOIUrl":"10.1111/jfd.14009","url":null,"abstract":"<p>Four-finger threadfin, <i>Eleutheronema tetradactylum</i> farming in southern Taiwan has been facing disease problems caused by <i>Streptococcus iniae</i> since 2018. The development of a vaccine against infectious <i>S</i>. <i>iniae</i> in the cultured threadfin industry is necessary. Thus, this study aimed to examine the efficacy of threadfin immunized formalin-killed cells (FKC) from <i>S</i>. <i>iniae</i> GSI-111 for 42 days post-vaccination (dpv) using two doses of FKC alone (a booster at 14 dpv) as group A, and FKC mixed with ISA763A adjuvant using a single dose as group B or double doses as group C. Immunoglobulin (Ig)-M was purified from threadfin, and rabbit anti-threadfin IgM polyclonal antibodies were used to detect antibody level in immunized fish; the vaccinated group A displayed higher levels at 3 dpv and all vaccinated treatments demonstrated high antibody levels between 14 and 42 dpv. All vaccine groups showed significantly higher values of lysozyme activity at 42 dpv compared with the control group; the vaccinated A group peaked at 14 dpv. The expression profiles of pro-inflammatory and immune-related genes, <i>TNF-α</i>, <i>IL-12A</i>, and <i>C2</i> were upregulated at 3 dpv, while <i>CD8A</i> and chemokine receptor <i>CXCR4</i> were upregulated at 42 dpv. Finally, the threadfins were challenged with <i>S</i>. <i>iniae</i> at 42 dpv. The average relative percent survival was 96% for vaccination A and B treatments, and 100% for vaccination C treatment. In summary, this study demonstrated that FKC vaccines whether formulated with an adjuvant could stimulate immune response and effective protect threadfins against <i>S</i>. <i>iniae</i> infection.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":"47 11","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142107996","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":"Exploring the antiparasitic and antimicrobial potential of Schinus terebinthifolius Raddi essential oil against fish and shrimp pathogens","authors":"Jucimauro de Araújo Pereira Junior,&nbsp;Gracienhe Gomes dos Santos,&nbsp;Domickson Silva Costa,&nbsp;Graziella Vivine Gonçalves de Matos Silva,&nbsp;Paola Capistrano dos Santos,&nbsp;Gabriele Bueno dos Anjos,&nbsp;Luiz Felipe Kretzer de Moraes,&nbsp;Claudia Andrea Lima Cardoso,&nbsp;Arlene Sobrinho Ventura,&nbsp;Natalino da Costa Sousa,&nbsp;Mauricio Laterça Martins","doi":"10.1111/jfd.14010","DOIUrl":"10.1111/jfd.14010","url":null,"abstract":"<p>This study aimed to perform in vitro antiparasitic and antimicrobial tests with the essential oil (EO) of <i>Schinus terebinthifolius</i> against of fish and shrimp. The chemical composition of the EO of <i>S. terebinthifolius</i> was determined by gas chromatography. For the antiparasitic test, the protozoan <i>Epistylis</i> sp. obtained from parasitized <i>Oreochromis niloticus</i> was used, and exposed to different concentrations of EO (2%, 1%, 0.5%, 0.25%), and control with 1% grain alcohol. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) test with EO of <i>S. terebinthifolius</i> evaluated the antimicrobial potential, with serial dilutions starting at 2% and control with 1% grain alcohol, using the strains of <i>Aeromonas hydrophila</i> (2.2 × 10⁸ CFU mL⁻¹), <i>Edwardsiella tarda</i>, <i>Vibrio parahaemolyticus</i>, <i>V. harveyi</i>, and <i>V. alginolyticus</i> (2.0 × 10⁸ CFU mL⁻¹). Chemical analysis revealed that the major EO compounds of <i>S. terebinthifolius</i> were δ-3-Carene (56.00%) and α-Pinene (16.89%). In the antiparasitic test, the concentration of 2% EO showed 100% efficacy against <i>Epistylis</i> sp. within 5 min. In the antimicrobial tests, the concentration of 2% EO was effective against all bacteria tested. The EO of <i>S. terebinthifolius</i> demonstrated antiparasitic and antimicrobial activity at a concentration of 2%, standing out as an alternative to conventional antibiotics.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":"47 11","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142008887","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":"Assessment of dietary yeast-based additives for cultured catfish and tilapia health","authors":"Guillaume Cacot,&nbsp;D. Allen Davis,&nbsp;Benjamin R. LaFrentz,&nbsp;Mark R. Liles,&nbsp;Ian A. E. Butts,&nbsp;Craig A. Shoemaker,&nbsp;Benjamin H. Beck,&nbsp;Mark Farmer,&nbsp;Timothy J. Bruce","doi":"10.1111/jfd.14008","DOIUrl":"10.1111/jfd.14008","url":null,"abstract":"<p>Channel catfish (<i>Ictalurus punctatus</i>) and Nile tilapia (<i>Oreochromis niloticus</i>) are two aquaculture species of great importance. Intensive production is often hindered by poor growth performance and disease mortality. The aim of this study was to evaluate the potential of a commercial fermented yeast product, DVAQUA, on channel catfish and Nile tilapia growth performance metrics and disease resistance. Channel catfish and Nile tilapia were fed practical diets supplemented with 0%, 0.1% or 0.4% of DVAQUA over approximately 2-month feeding periods in recirculation aquaculture systems. To assess the potential of the postbiotic against common aquaculture pathogens, juvenile catfish were subsequently challenged by immersion with <i>Edwardsiella ictaluri</i> S97-773 or virulent <i>Aeromonas hydrophila</i> ML09-119. Nile tilapia juveniles were challenged by injection with <i>Streptococcus iniae</i> ARS-98-60. Serum lysozyme activity, blood chemistry and growth metrics were measured at the end of the feeding period, but no differences were observed across the different metrics, except for survival. For the pathogen challenges, there were no differences in endpoint mortality for channel catfish with either pathogen (<i>p</i> &gt; .05). In contrast, Nile tilapia survivability to <i>S. iniae</i> infection increased proportionally to the inclusion of DVAQUA (<i>p</i> = .005). Changes to sera lysozyme activity were also noted in the tilapia trial, with a reduction of activity in the fish fed the 0.4% DVAQUA diet compared to the control diet (<i>p</i> = .031). Expression profiles of proinflammatory genes and antibodies were also found to be modulated in channel catfish fed the postbiotic, indicating some degree of protective response. These results suggest that this postbiotic may be beneficial in protecting Nile tilapia against <i>S. iniae</i> infection by influencing immune parameters and additional research is needed to evaluate the potential of this DVAQUA for improving catfish health and disease control.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":"47 11","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142004316","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":"Mortality events associated with microsporidian, Spraguea sp., in White Trevally culture in Japan","authors":"Tomofumi Kurobe,&nbsp;Ikunari Kiryu","doi":"10.1111/jfd.14006","DOIUrl":"10.1111/jfd.14006","url":null,"abstract":"<p>In 2021, White Trevally or Striped Jack cultured in the western part of Japan exhibited mild, but chronic mortalities from late September through early October. The cumulative mortality rate was approximately 0.02% per a net pen containing approximately 50,000 fish. Although the cumulative mortality rate was not high, most of the fish in net pens showed characteristic gross signs and an abnormal swimming behaviour. The body of diseased fish became pale and the yellow lines on the lateral sides of fish body became darken. In addition, silver lines along the dorsal fin became apparent. Loss of schooling behaviour was noted during the mortality event. In addition, affected fish became lethargic and failed to swim against current, or frequently stopped swimming and sank to the bottom of net pens after feeding. The goal of this study was to identify the cause of the mortality event. To achieve the goal, we used histopathology and metatranscriptome analysis. Histopathological examination revealed that xenoma of microsporidian were frequently observed in the nerve axon in the brain and spinal cord. Spores observed in the sections were stained with a fluorescent dye, Uvitex 2B, indicating those spores are microsporidian. The data from metatranscriptome analysis indicated that the microsporidian is <i>Spraguea</i> sp. The microsporidian was frequently detected from diseased fish with similar symptoms collected in the same region, suggesting that the microsporidian was highly associated with abnormal swimming behaviour of fish.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":"47 11","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141971290","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":"Diversity in clinical isolates of Ictalurid herpesvirus 1 (IcHV1) from U.S. farm-raised catfish and virulence assessment in channel and channel × blue catfish hybrids","authors":"Arun Venugopalan,&nbsp;Danielle White,&nbsp;Adrián López-Porras,&nbsp;Lorelei Ford,&nbsp;Cynthia Ware,&nbsp;Marsha A. Lewis,&nbsp;James M. Steadman,&nbsp;Lester H. Khoo,&nbsp;Bradley Richardson,&nbsp;Charles M. Walker,&nbsp;Todd S. Byars,&nbsp;David J. Wise,&nbsp;Matt J. Griffin,&nbsp;Larry A. Hanson","doi":"10.1111/jfd.14005","DOIUrl":"10.1111/jfd.14005","url":null,"abstract":"<p>Ictalurid herpesvirus 1 (IcHV1) is the most significant viral agent in U.S. catfish aquaculture. Little is known regarding the genetic stability and antigenic variability of IcHV1. Herein, the genetic and antigenic diversity of IcHV1 field isolates was assessed by restriction fragment length polymorphism (RFLP) analysis and serum neutralization assays. RFLP analysis identified two distinct genotypes (IcHV1A and IcHV1B), both discrete from blue catfish alloherpesvirus (BCAHV). Neutralization assays with anti-IcHV1 monoclonal antibody Mab-95 indicate shared antigenic determinants for IcHV1A and IcHV1B that are absent from BCAHV, which Mab-95 did not neutralize. Virulence assessments with representative isolates demonstrate significant differences between isolates within RFLP groups and pooled RFLP group data suggest IcHV1B (pooled survival [mean ± SE]: 58.3% ± 2.6) may be more virulent than IcHV1A (survival: 68.6% ± 2.4). Rechallenges with representative IcHV1A and IcHV1B isolates indicate a cross-protective effect, with fish surviving initial exposure to IcHV1A or IcHV1B showing robust protection when subsequently re-exposed to IcHV1A or IcHV1B. This work demonstrated significant differences in virulence between case isolates, identifying two discrete IcHV1 lineages, distinct from BCAHV, with similar virulence in channel and channel × blue catfish hybrids and a cross-protective effect in catfish surviving exposure to either lineage.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":"47 11","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141916877","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":"Medicinal herbs, bioactives, phytochemicals and functional foods for health of aquatic species: Exploring a burgeoning focus for fish health sciences.","authors":"David J Speare, Barbara F Nowak, Heike Schmidt-Posthaus, Saengchan Senapin","doi":"10.1111/jfd.13999","DOIUrl":"https://doi.org/10.1111/jfd.13999","url":null,"abstract":"","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":" ","pages":"e13999"},"PeriodicalIF":2.2,"publicationDate":"2024-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141889455","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":"Multiplex PCR assay for the accurate and rapid detection and differentiation of Lactococcus garvieae and L. petauri","authors":"Dilek Ustaoglu,&nbsp;Rafet Çağrı Öztürk,&nbsp;Mustafa Ture,&nbsp;Silvia Colussi,&nbsp;Paolo Pastorino,&nbsp;Ana Isabel Vela,&nbsp;Charalampos Kotzamanidis,&nbsp;Donatella Volpatti,&nbsp;Pier Luigi Acutis,&nbsp;Ilhan Altinok","doi":"10.1111/jfd.14004","DOIUrl":"10.1111/jfd.14004","url":null,"abstract":"<p>Lactococcosis is a common bacterial fish disease caused by <i>Lactococcus garvieae</i>, <i>L. petauri and L. formosensis</i>. Although there are different PCR-based techniques to identify the etiological agent, none of these can differentiate these two bacteria without sequencing PCR-amplified fragments. In the present study, we developed a multiplex PCR assay for simultaneous detection and differentiation of <i>L. garvieae</i> and <i>L. petauri</i>. The specificity of the primers was validated against the bacterial DNA of the targeted and non-targeted bacteria. The sizes of the PCR amplicons were obtained as 204 bp for the DUF1430 domain-containing protein gene of <i>L. garvieae</i>, 465 bp for the Lichenan permease IIC component gene of <i>L. petauri</i>, and 302 bp for the teichoic acid biosynthesis protein F gene of both <i>L. garvieae</i> and <i>L. petauri</i>. The PCR amplicons were clearly separated by agarose gel electrophoresis. The multiplex PCR assay did not produce any amplification products with the DNA of the non-targeted bacteria. The multiplex PCR detection limits for <i>L. garvieae</i> and <i>L. petauri</i> were 5 and 4 CFU in pure culture and 50 and 40 CFU/g in spiked tissue samples, respectively. It takes less than 2 h from plate-cultured bacteria and 3 h from tissue samples to get results. In conclusion, the developed multiplex PCR assay is a rapid, specific, accurate, and cost-effective method for the detection and differentiation of <i>L. garvieae</i> and <i>L. petauri</i> and is suitable to be used for routine laboratory diagnosis of <i>L. garvieae</i> and <i>L. petauri</i>.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":"47 11","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jfd.14004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141889456","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":"The HSP70 and IL-1β of Nile tilapia as molecular adjuvants can enhance the immune protection of DNA vaccine against Streptococcus agalactiae infection","authors":"Fei-Fan Xu,&nbsp;Zhu-Yang Deng,&nbsp;Jun-Jie Sheng,&nbsp;Bin Zhu","doi":"10.1111/jfd.14002","DOIUrl":"10.1111/jfd.14002","url":null,"abstract":"<p>Globally, streptococcal disease caused by <i>Streptococcus agalactiae</i> is known for its high mortality rate, which severely limits the development of the tilapia breeding industry. As a third-generation vaccine, DNA vaccines have shown great application prospects in the prevention and control of aquatic diseases, but their low immunogenicity limits their development. The combination of DNA vaccines and molecular adjuvants proved to be an effective method for inducing protective immunity. This study constructed recombinant plasmids encoding tilapia <i>HSP70</i> and <i>IL-1β</i> genes (pcHSP70 and pcIL-1β) to verify their effectiveness as molecular adjuvants for <i>S. agalactiae</i> DNA vaccine (pcSIP) in the immunized tilapia model. The results revealed that serum-specific IgM production, enzyme activities, and immune-related gene expression in tilapia immunized with pcSIP plus pcHSP70 or pcIL-1β were significantly higher than those in tilapia immunized with pcSIP alone. It is worth noting that combination with molecular adjuvants improved the immune protection of DNA vaccines, with a relative percentage survival (RPS) of 51.72% (pcSIP plus pcHSP70) and 44.83% (pcSIP plus pcIL-1β), respectively, compared with that of pcSIP alone (24.14%). Thus, our study indicated that <i>HSP70</i> and <i>IL-1β</i> in tilapia are promising molecular adjuvants of the DNA vaccine in controlling <i>S. agalactiae</i> infection.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":"47 11","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141792635","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":"Antimicrobial and anthelmintic effects of copper nanoparticles against Koi carp parasites and their toxicity","authors":"Gracienhe Gomes dos Santos,&nbsp;Liseth Vanessa Perengue Riofrio,&nbsp;Ana Paula Sousa,&nbsp;Paola Capistrano Santos,&nbsp;Alexandre Vaz Silva,&nbsp;Emilly Monteiro Lopes,&nbsp;Domickson Silva Costa,&nbsp;Jucimauro de Araújo Pereira Júnior,&nbsp;Giulia Beatrice Ferreira,&nbsp;Graziella Vivine Gonçalves de Matos Silva,&nbsp;Marilia Tedesco,&nbsp;Diego José Nogueira,&nbsp;Gabriela Tomas Jerônimo,&nbsp;Mauricio Laterça Martins","doi":"10.1111/jfd.14003","DOIUrl":"10.1111/jfd.14003","url":null,"abstract":"<p>This study investigated the in vitro antimicrobial and anthelmintic effect of copper nanoparticles (CuNPs) against the bacterium <i>Aeromonas hydrophila</i>, the monogeneans <i>Dactylogyrus minutus</i>, <i>Dactylogyrus extensus</i>, <i>Gyrodactylus cyprini</i>, and the cestode <i>Schyzocotyle acheilognathi</i>, as well as their toxicity to <i>Cyprinus carpio</i> Koi. In the antimicrobial in vitro test, the inhibition zone method and minimum inhibitory concentration (MIC) were performed. In order to determine the time and efficacy of monogenean parasite mortality, the parasites were exposed to CuNP concentrations of 20, 50, 100, 150, 200, and 300 mg L⁻¹, and a control group with tank water and one with copper sulphate pentahydrate (CuSO₄.₅H₂O) at a concentration of 0.3 mg L⁻¹, performed in triplicate. The parasites were observed every 10 min for 300 min, and mortality was recorded. For the cestodes, parasites were immersed in CuNP concentrations of 50, 100, 150, and 300 mg L⁻¹. At the end of the in vitro tests, the anthelmintic efficacy of each treatment was calculated. To assess the tolerance and toxicity in fish, they were exposed to CuNP concentrations of 0.6, 1.25, 2.5, 5, 10, 20, and 50 mg L⁻¹ for 12 h. The MIC demonstrated that CuNPs effectively inhibited the growth of <i>A</i>. <i>hydrophila</i> up to a dilution of 12,500 mg L⁻¹ and showed an inhibition zone of 14.0 ± 1.6 mm for CuNPs. The results of anthelmintic activity showed a dose-dependent effect of concentration for both groups of parasites, with the most effective concentration being 300 mg L⁻¹ in 120 min. In the toxicity test, the carps showed tolerance to lower concentrations. The study indicated that CuNPs were effective against the studied pathogens. However, it proved to be toxic to fish at high concentrations. The use of low concentrations is recommended still requires further investigation.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":"47 11","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141792634","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":"Characterization of Photobacterium damselae subsp. damselae isolated from diseased Asian seabass (Lates calcarifer) and the preliminary development of a formalin-killed cell vaccine","authors":"Warisara Weawsawang,&nbsp;Theeyathart Homsombat,&nbsp;Saransiri Nuanmanee,&nbsp;Nattakan Saleetid,&nbsp;Jumroensri Thawonsuwan,&nbsp;Ansaya Pumchan,&nbsp;Ikuo Hirono,&nbsp;Hidehiro Kondo,&nbsp;Sasimanas Unajak","doi":"10.1111/jfd.13987","DOIUrl":"10.1111/jfd.13987","url":null,"abstract":"<p>Asian seabass (<i>Lates calcarifer</i>) is an economically important fish species that is widely cultivated in Thailand. However, aquaculture of Asian seabass is limited by infectious diseases. One of the most serious diseases is photobacteriosis, caused by <i>Photobacterium damselae</i>. Vaccination is recognized as an efficient disease prevention and pathogen control method for strengthening the aquaculture industry. To promote vaccine development, the characterization of pathogenic bacteria and their pathogenesis is required. In this study, isolates of <i>P. damselae</i> were obtained from commercial aquaculture farms in Thailand during 2019–2021. Analyses of 16S rRNA and the urease subunit alpha genes identified the isolates as <i>P. damselae</i> subsp. <i>damselae</i> (<i>Phdd</i>). Antibiotic susceptibility analyses showed that all <i>Phdd</i> isolates were resistant to amoxicillin (10 μg). Haemolysis and phospholipase activities were used to categorize <i>P. damselae</i> into three groups based on their biological activities. The pathogenicity of four candidates (SK136, PD001, PD002 and T11L) was tested in Asian seabass. Isolate SK136 showed the highest virulence, with a lethal dose (LD₅₀) of 1.47 × 10⁵ CFU/fish, whereas isolate PD001 did not show any virulence. Genotypic characterization, based on multi-locus sequence typing analysis, demonstrated that all candidates were novel strains with new sequence types (64, 65, 66 and 67). Preliminary vaccination using formalin-killed cells (FKCs) protected Asian seabass from artificial challenges. Taken together, these results provide fundamental knowledge for vaccine development against <i>Phdd</i> infection in Asian seabass.</p>","PeriodicalId":15849,"journal":{"name":"Journal of fish diseases","volume":"47 10","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141788184","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}