Fusarium is a huge genus of filamentous fungi that has the potential to cause emerging diseases. Members of this genus can cause infections in plants, animals and humans. Here, we report the isolation of F. oxysporum and F. equiseti from 2 important fish species, Oncorhynchus mykiss (rainbow trout) and Tor putitora (golden mahseer), respectively. F. oxysporum has emerged as a significant fungal pathogen causing infection in many fish. However, F. equiseti has been isolated mainly from plants. As far as the available literatures are concerned, this is the first report on the isolation of F. oxysporum and F. equiseti from these hosts. The isolates were identified based on growth morphology and microscopic observation. F. oxysporum produced violet pigmentation on potato dextrose agar, while F. equiseti had yellow colouration. F. oxysporum produced 1- to 2-celled microconidia along with straight or curved macroconidia having 3 to 4 septa. F. equiseti produced abundant macroconidia with 4 or more septa. Species were further confirmed based on the nucleotide sequences of the internal transcribed spacer region. In a molecular phylogeny analysis, F. oxysporum and F. equiseti formed 2 different clades. In an antifungal sensitivity assay, F. oxysporum was found to be susceptible to clotrimazole with a minimum inhibitory concentration of 1.0 µg ml-1, whereas F. equiseti was susceptible to clotrimazole, ketoconazole and fluconazole. Overall, the main findings of this study are the infection of new hosts by Fusarium species and the limited activity of many antifungal drugs against these pathogens.
镰刀菌是一个庞大的丝状真菌属,有可能导致新出现的疾病。该属的成员可导致植物、动物和人类感染。在此,我们报告了分别从两种重要鱼类 Oncorhynchus mykiss(虹鳟鱼)和 Tor putitora(金鳟鱼)中分离出 F. oxysporum 和 F. equiseti 的情况。F. oxysporum 已成为导致许多鱼类感染的重要真菌病原体。然而,F. equiseti 主要是从植物中分离出来的。就现有文献而言,这是首次从这些寄主中分离出 F. oxysporum 和 F. equiseti 的报告。根据生长形态和显微镜观察对分离物进行了鉴定。F. oxysporum 在马铃薯葡萄糖琼脂上产生紫色色素,而 F. equiseti 则呈黄色。F. oxysporum 产生 1 至 2 室的微菌丝,以及有 3 至 4 个隔膜的直或弯曲的大菌丝。F. equiseti 产生大量具有 4 个或更多隔膜的大锥体。根据内部转录间隔区的核苷酸序列进一步确认了物种。在分子系统进化分析中,F. oxysporum 和 F. equiseti 形成了两个不同的支系。在抗真菌敏感性试验中,发现 F. oxysporum 对克霉唑敏感,最低抑菌浓度为 1.0 µg ml-1,而 F. equiseti 对克霉唑、酮康唑和氟康唑敏感。总之,这项研究的主要发现是镰刀菌感染了新的寄主,而许多抗真菌药物对这些病原体的活性有限。
{"title":"Identification and antifungal sensitivity of Fusarium species isolated from piscine hosts.","authors":"Victoria Chanu Khangembam, Dimpal Thakuria, Ritesh Shantilal Tandel, Vinita Pant, Nityanand Pandey, Pramod Kumar Pandey","doi":"10.3354/dao03809","DOIUrl":"https://doi.org/10.3354/dao03809","url":null,"abstract":"<p><p>Fusarium is a huge genus of filamentous fungi that has the potential to cause emerging diseases. Members of this genus can cause infections in plants, animals and humans. Here, we report the isolation of F. oxysporum and F. equiseti from 2 important fish species, Oncorhynchus mykiss (rainbow trout) and Tor putitora (golden mahseer), respectively. F. oxysporum has emerged as a significant fungal pathogen causing infection in many fish. However, F. equiseti has been isolated mainly from plants. As far as the available literatures are concerned, this is the first report on the isolation of F. oxysporum and F. equiseti from these hosts. The isolates were identified based on growth morphology and microscopic observation. F. oxysporum produced violet pigmentation on potato dextrose agar, while F. equiseti had yellow colouration. F. oxysporum produced 1- to 2-celled microconidia along with straight or curved macroconidia having 3 to 4 septa. F. equiseti produced abundant macroconidia with 4 or more septa. Species were further confirmed based on the nucleotide sequences of the internal transcribed spacer region. In a molecular phylogeny analysis, F. oxysporum and F. equiseti formed 2 different clades. In an antifungal sensitivity assay, F. oxysporum was found to be susceptible to clotrimazole with a minimum inhibitory concentration of 1.0 µg ml-1, whereas F. equiseti was susceptible to clotrimazole, ketoconazole and fluconazole. Overall, the main findings of this study are the infection of new hosts by Fusarium species and the limited activity of many antifungal drugs against these pathogens.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142105388","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}
Jie Liu, Chenhao Teng, Xurui Zheng, La Xu, Haipeng Cao, Chunlei Gai
Shewanella putrefaciens has been recognized as an emerging important pathogen in aquaculture. However, scarce information is available on the characterization and microbial control of S. putrefaciens as a causal agent of hepatopancreas necrosis disease in Chinese mitten crab Eriocheir sinensis. In this study, a multi-resistant S. putrefaciens isolate (DZ-A) was identified as a causal pathogen of hepatopancreas necrosis disease in Chinese mitten crabs. It showed a lethal dose (LD50) of 2.20 × 105 CFU ml-1 in Chinese mitten crabs, and multiple resistance to aminoglycoside, chloramphenicol, macrolide, penicillin, peptide, and tetracycline antimicrobials. In addition, Bdellovibrio powder exhibited a significant antibacterial effect against the pathogenic S. putrefaciens, and conferred significant protection to challenged Chinese mitten crabs with relative percentage survivals of 80.00% to 93.33% via significant improvement in their immune response and antioxidant capability. The findings of this study provide valuable insights into the phenotypic characterization and biological control of pathogenic S. putrefaciens in Chinese mitten crabs.
腐生雪旺氏菌已被认为是水产养殖中一种新出现的重要病原体。然而,有关中华绒螯蟹肝胰腺坏死病病原S. putrefaciens的特征和微生物控制的信息却很少。在这项研究中,一个多重耐药的中华绒螯蟹分离株(DZ-A)被确定为中华绒螯蟹肝胰腺坏死病的病原体。它对中华绒螯蟹的致死剂量(LD50)为 2.20 × 105 CFU ml-1,并对氨基糖苷类、氯霉素、大环内酯类、青霉素、肽类和四环素类抗菌药具有多重耐药性。此外,Bdellovibrio 菌粉对致病性 S. putrefaciens 有显著的抗菌作用,并通过显著改善中华绒螯蟹的免疫反应和抗氧化能力,为中华绒螯蟹提供显著的保护,相对存活率为 80.00% 至 93.33%。这项研究的结果为中华绒螯蟹致病性 S. putrefaciens 的表型特征和生物防治提供了有价值的见解。
{"title":"Shewanella putrefaciens as an emerging pathogen of hepatopancreas necrosis disease in Chinese mitten crab Eriocheir sinensis.","authors":"Jie Liu, Chenhao Teng, Xurui Zheng, La Xu, Haipeng Cao, Chunlei Gai","doi":"10.3354/dao03811","DOIUrl":"https://doi.org/10.3354/dao03811","url":null,"abstract":"<p><p>Shewanella putrefaciens has been recognized as an emerging important pathogen in aquaculture. However, scarce information is available on the characterization and microbial control of S. putrefaciens as a causal agent of hepatopancreas necrosis disease in Chinese mitten crab Eriocheir sinensis. In this study, a multi-resistant S. putrefaciens isolate (DZ-A) was identified as a causal pathogen of hepatopancreas necrosis disease in Chinese mitten crabs. It showed a lethal dose (LD50) of 2.20 × 105 CFU ml-1 in Chinese mitten crabs, and multiple resistance to aminoglycoside, chloramphenicol, macrolide, penicillin, peptide, and tetracycline antimicrobials. In addition, Bdellovibrio powder exhibited a significant antibacterial effect against the pathogenic S. putrefaciens, and conferred significant protection to challenged Chinese mitten crabs with relative percentage survivals of 80.00% to 93.33% via significant improvement in their immune response and antioxidant capability. The findings of this study provide valuable insights into the phenotypic characterization and biological control of pathogenic S. putrefaciens in Chinese mitten crabs.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142105389","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}
The assessment of free-ranging cetacean health through the study of skin conditions using photographs has gained prominence in recent years. However, little attention has been given to the relationships between cetacean skin conditions, species, and body condition. To explore this relationship among baleen whale species along the northwestern coast of Spain, we employed a non-invasive method involving photograph analysis. In this study, we examined skin conditions (including injuries, epizoites and ectoparasites, pigmentation disorders, skin lesions, and anatomical malformations) and body condition (overall physical contours and form, as an indicator of nutritional status and health) in 3 species of whales (blue, fin, and minke whales). This methodology facilitated the identification of 29 subcategories of distinct skin conditions and an assessment of body condition over a 5 yr period (2017 to 2021). In our study, we present evidence linking hypopigmentation, protruding pieces of tissue, and tattoo-like lesions to 'Poor' body condition in the 3 baleen whale species. Fin whales exhibited a higher susceptibility to mottling (prevalence = 17.7%), while blue whales were more prone to starbursts (prevalence = 90.5%). Additionally, we found a significant relationship between skin condition diversity and individual body condition. Our findings contribute valuable information to the broader understanding of the health status of baleen whales. Further investigations are necessary to delve into the etiology of the documented skin conditions and their potential implications for individual survival. This study serves as a foundation for ongoing research aimed at advancing our comprehension of these findings.
{"title":"Relationship between skin and body condition in three species of baleen whales.","authors":"Joyce Neves, Séverine Methion, Bruno Díaz López","doi":"10.3354/dao03808","DOIUrl":"https://doi.org/10.3354/dao03808","url":null,"abstract":"<p><p>The assessment of free-ranging cetacean health through the study of skin conditions using photographs has gained prominence in recent years. However, little attention has been given to the relationships between cetacean skin conditions, species, and body condition. To explore this relationship among baleen whale species along the northwestern coast of Spain, we employed a non-invasive method involving photograph analysis. In this study, we examined skin conditions (including injuries, epizoites and ectoparasites, pigmentation disorders, skin lesions, and anatomical malformations) and body condition (overall physical contours and form, as an indicator of nutritional status and health) in 3 species of whales (blue, fin, and minke whales). This methodology facilitated the identification of 29 subcategories of distinct skin conditions and an assessment of body condition over a 5 yr period (2017 to 2021). In our study, we present evidence linking hypopigmentation, protruding pieces of tissue, and tattoo-like lesions to 'Poor' body condition in the 3 baleen whale species. Fin whales exhibited a higher susceptibility to mottling (prevalence = 17.7%), while blue whales were more prone to starbursts (prevalence = 90.5%). Additionally, we found a significant relationship between skin condition diversity and individual body condition. Our findings contribute valuable information to the broader understanding of the health status of baleen whales. Further investigations are necessary to delve into the etiology of the documented skin conditions and their potential implications for individual survival. This study serves as a foundation for ongoing research aimed at advancing our comprehension of these findings.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141981959","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}
Miku Kawahara, Theresa T Cody, Roy P E Yanong, Eileen Henderson, Zeinab Yazdi, Esteban Soto
Piscine francisellosis is one of the most important bacterial diseases affecting various fish species worldwide. Francisella orientalis, F. noatunensis, and F. salimarina (F. marina) have been reported as etiological agents of disease in fish. A Francisella sp. was isolated from several diseased red drum Sciaenops ocellatus experiencing morbidity in Florida, USA, in 2008. In this study, molecular and phenotypic characterization of the recovered isolate was conducted. Phenotypically, the isolate showed a biochemical reaction profile distinct from that of F. orientalis and F. salimarina. Although the 16S rRNA sequence of this isolate shared 99.61% identity to the type strain of F. philomiragia O#319LT, whole genome analysis (average nucleotide identity <95%; digital DNA-DNA hybridization <70%) and a multilocus sequence analysis of 8 concatenated housekeeping genes in comparison with other Francisella spp. indicated that this isolate was a novel Francisella species, more closely related to F. orientalis. Immersion, intracoelomic injection, and co-habitation challenges using a Nile tilapia Oreochromis niloticus fingerling model of infection were done to investigate virulence in a piscine model. Variably pigmented granulomas and pigmented macrophage aggregates were observed in the kidneys and spleens of the challenged fish, but no mortality was recorded during the 15 d challenge period, suggesting that this novel Francisella sp. might be an opportunistic pathogen of fish. Based on the phenotypic and genotypic differences from other Francisella spp. observed in this study, we propose the name Francisella sciaenopsi sp. nov. for this novel isolate.
鱼类弗朗西斯菌病是影响全球各种鱼类的最重要的细菌性疾病之一。据报道,东方弗朗西斯菌、Noatunensis 弗朗西斯菌和 Salimarina 弗朗西斯菌(F. marina)是鱼类疾病的病原体。2008 年在美国佛罗里达州,从几条发病的红鼓(Sciaenops ocellatus)中分离出了弗朗西斯菌。本研究对该分离菌进行了分子和表型鉴定。从表型上看,该分离株的生化反应特征与 F. orientalis 和 F. salimarina 不同。虽然该分离株的 16S rRNA 序列与 F. philomiragia O#319LT 的模式菌株有 99.61% 的一致性,但全基因组分析(平均核苷酸一致性
{"title":"Francisella sciaenopsi sp. nov. isolated from diseased red drum Sciaenops ocellatus in Florida, USA.","authors":"Miku Kawahara, Theresa T Cody, Roy P E Yanong, Eileen Henderson, Zeinab Yazdi, Esteban Soto","doi":"10.3354/dao03803","DOIUrl":"https://doi.org/10.3354/dao03803","url":null,"abstract":"<p><p>Piscine francisellosis is one of the most important bacterial diseases affecting various fish species worldwide. Francisella orientalis, F. noatunensis, and F. salimarina (F. marina) have been reported as etiological agents of disease in fish. A Francisella sp. was isolated from several diseased red drum Sciaenops ocellatus experiencing morbidity in Florida, USA, in 2008. In this study, molecular and phenotypic characterization of the recovered isolate was conducted. Phenotypically, the isolate showed a biochemical reaction profile distinct from that of F. orientalis and F. salimarina. Although the 16S rRNA sequence of this isolate shared 99.61% identity to the type strain of F. philomiragia O#319LT, whole genome analysis (average nucleotide identity <95%; digital DNA-DNA hybridization <70%) and a multilocus sequence analysis of 8 concatenated housekeeping genes in comparison with other Francisella spp. indicated that this isolate was a novel Francisella species, more closely related to F. orientalis. Immersion, intracoelomic injection, and co-habitation challenges using a Nile tilapia Oreochromis niloticus fingerling model of infection were done to investigate virulence in a piscine model. Variably pigmented granulomas and pigmented macrophage aggregates were observed in the kidneys and spleens of the challenged fish, but no mortality was recorded during the 15 d challenge period, suggesting that this novel Francisella sp. might be an opportunistic pathogen of fish. Based on the phenotypic and genotypic differences from other Francisella spp. observed in this study, we propose the name Francisella sciaenopsi sp. nov. for this novel isolate.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141981958","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}
Many studies have demonstrated that long double-stranded RNAs (dsRNAs) targeting essential genes of white spot syndrome virus (WSSV) can induce a sequence-specific antiviral RNA interference (RNAi) response in shrimp, thereby offering protection against WSSV infection. However, further experimental data on the required dose of dsRNAs and the duration of protection from a single administration are necessary to establish RNAi-mediated methods as effective and practical antiviral measures. In this study, we evaluated the protective efficacy and the duration of protection provided by a single administration of various doses of long dsRNA targeting WSSV ribonucleotide reductase 2 (rr2) in white-leg shrimp Litopenaeus vannamei. The protective efficacy of long dsRNA targeting WSSV rr2 was not diminished by the reduction of the dose to 100 ng g-1 of body weight, suggesting that a relatively low dose can effectively induce an RNAi response in shrimp. Furthermore, shrimp were well-protected against WSSV challenges for up to 4 wk post-administration of the rr2-targeting long dsRNA, although the protective effect almost disappeared at 6 wk post-administration. These results suggest that long dsRNAs can provide protection against WSSV for at least 1 mo, and monthly administration of long dsRNAs could serve as a long-term protective strategy for shrimp against WSSV.
{"title":"RNA interference targeting WSSV ribonucleotide reductase 2 provides long-term protection against infection in Litopenaeus vannamei.","authors":"Soon Joo Hong, Ki Hong Kim","doi":"10.3354/dao03805","DOIUrl":"10.3354/dao03805","url":null,"abstract":"<p><p>Many studies have demonstrated that long double-stranded RNAs (dsRNAs) targeting essential genes of white spot syndrome virus (WSSV) can induce a sequence-specific antiviral RNA interference (RNAi) response in shrimp, thereby offering protection against WSSV infection. However, further experimental data on the required dose of dsRNAs and the duration of protection from a single administration are necessary to establish RNAi-mediated methods as effective and practical antiviral measures. In this study, we evaluated the protective efficacy and the duration of protection provided by a single administration of various doses of long dsRNA targeting WSSV ribonucleotide reductase 2 (rr2) in white-leg shrimp Litopenaeus vannamei. The protective efficacy of long dsRNA targeting WSSV rr2 was not diminished by the reduction of the dose to 100 ng g-1 of body weight, suggesting that a relatively low dose can effectively induce an RNAi response in shrimp. Furthermore, shrimp were well-protected against WSSV challenges for up to 4 wk post-administration of the rr2-targeting long dsRNA, although the protective effect almost disappeared at 6 wk post-administration. These results suggest that long dsRNAs can provide protection against WSSV for at least 1 mo, and monthly administration of long dsRNAs could serve as a long-term protective strategy for shrimp against WSSV.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141981960","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}
Vladimir Radosavljevic, Oliver Radanovic, Dimitrije Glišic, Nemanja Zdravkovic, Jelena Maksimovic-Zoric, Ksenija Nesic, Bozidar Savic, Bozidar Raškovic
Ichthyophonosis is a disease caused by the mesomycetozoean parasite Ichthyophonus hoferi that affects a variety of fish species, including rainbow trout Oncorhynchus mykiss Walbaum. This disease is characterized by granulomatous lesions and necrosis in various organs, which can have severe impacts on the health and welfare of the fish. Ichthyophonosis has been found in several parts of the world, including Europe, and is a significant concern in the aquaculture industry and for populations of wild marine fishes. The rainbow trout is a widely cultured salmonid species in many countries, including Serbia. Although the presence of I. hoferi in rainbow trout has been reported in several countries, it has never been documented in Serbia. In this article, we report the first case of ichthyophonosis in rainbow trout in Serbia.
鱼鳞病是由介壳虫寄生虫 Ichthyophonus hoferi 引起的一种疾病,影响多种鱼类,包括虹鳟鱼 Oncorhynchus mykiss Walbaum。这种疾病的特点是各种器官出现肉芽肿病变和坏死,会严重影响鱼类的健康和福利。鱼鳞病已在包括欧洲在内的世界多个地区发现,是水产养殖业和野生海洋鱼类种群的重大问题。虹鳟是包括塞尔维亚在内的许多国家广泛养殖的鲑鱼品种。虽然多个国家都有关于虹鳟鱼体内存在 I. hoferi 的报道,但在塞尔维亚却从未有过记录。本文报告了塞尔维亚首例虹鳟鱼嗜鱼鳞病病例。
{"title":"First case of ichthyophonosis in farmed rainbow trout Oncorhynchus mykiss in Serbia.","authors":"Vladimir Radosavljevic, Oliver Radanovic, Dimitrije Glišic, Nemanja Zdravkovic, Jelena Maksimovic-Zoric, Ksenija Nesic, Bozidar Savic, Bozidar Raškovic","doi":"10.3354/dao03804","DOIUrl":"https://doi.org/10.3354/dao03804","url":null,"abstract":"<p><p>Ichthyophonosis is a disease caused by the mesomycetozoean parasite Ichthyophonus hoferi that affects a variety of fish species, including rainbow trout Oncorhynchus mykiss Walbaum. This disease is characterized by granulomatous lesions and necrosis in various organs, which can have severe impacts on the health and welfare of the fish. Ichthyophonosis has been found in several parts of the world, including Europe, and is a significant concern in the aquaculture industry and for populations of wild marine fishes. The rainbow trout is a widely cultured salmonid species in many countries, including Serbia. Although the presence of I. hoferi in rainbow trout has been reported in several countries, it has never been documented in Serbia. In this article, we report the first case of ichthyophonosis in rainbow trout in Serbia.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141981957","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}
All species of the isopod family Cymothoidae are obligate fish parasites, extracting nourishment through hematophagy and tissue consumption. To elucidate the detrimental effects of this parasitic relationship upon the host fish, we examined body length, weight of body, gonad, liver and stomach contents, and condition factor of Japanese scad Decapterus maruadsi infected with the buccal cavity parasite Ceratothoa carinata in different seasons. During the host fish's breeding season in July, the wet weight and condition factor of male and female host fish ages 1 and 2 were conspicuously diminished. No impacts were detected in September, after the breeding season. We found no impact of the parasite on the stomach content weight or signs of prey fish in the stomachs. Thus, parasite infection with C. carinata potentially diminishes the reproductive success of the host fish by negatively impacting the host's physiological condition, particularly during the breeding season.
{"title":"Effects of buccal cavity parasite Ceratothoa carinata (Isopoda, Cymothoidae) on the condition and reproduction of its host fish Japanese scad Decapterus maruadsi.","authors":"Reina Nakano, Yuzumi Okumura, Hiroki Hata","doi":"10.3354/dao03806","DOIUrl":"https://doi.org/10.3354/dao03806","url":null,"abstract":"<p><p>All species of the isopod family Cymothoidae are obligate fish parasites, extracting nourishment through hematophagy and tissue consumption. To elucidate the detrimental effects of this parasitic relationship upon the host fish, we examined body length, weight of body, gonad, liver and stomach contents, and condition factor of Japanese scad Decapterus maruadsi infected with the buccal cavity parasite Ceratothoa carinata in different seasons. During the host fish's breeding season in July, the wet weight and condition factor of male and female host fish ages 1 and 2 were conspicuously diminished. No impacts were detected in September, after the breeding season. We found no impact of the parasite on the stomach content weight or signs of prey fish in the stomachs. Thus, parasite infection with C. carinata potentially diminishes the reproductive success of the host fish by negatively impacting the host's physiological condition, particularly during the breeding season.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141981956","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}
Soft tunic syndrome is an infectious disease caused by the flagellate Azumiobodo hoyamushi, which severely damages the aquaculture of the edible ascidian Halocynthia roretzi. Tunic is a cellulosic extracellular matrix entirely covering the body in ascidians and other tunicates, and its dense cuticle layer covers the tunic surface as a physical barrier against microorganisms. When the tunic of intact H. roretzi individuals was cut into strips, electron-dense fibers (DFs) appeared on the cut surface of the tunic matrix and aggregated to regenerate a new cuticular layer in seawater within a few days. DF formation was partially or completely inhibited in individuals with soft tunic syndrome, and DF formation was also inhibited by the presence of some proteases, indicating the involvement of proteolysis in the process of tunic softening as well as cuticle regeneration. Using pure cultures of the causative flagellate A. hoyamushi, the expression of protease genes and secretion of some proteases were confirmed by RNA-seq analysis and a 4-methylcoumaryl-7-amide substrate assay. Some of these proteases may degrade proteins in the tunic matrix. These findings suggest that the proteases of A. hoyamushi is the key to understanding the mechanisms of cuticular regeneration inhibition and tunic softening.
{"title":"Regeneration of tunic cuticle is suppressed in edible ascidian Halocynthia roretzi contracting soft tunic syndrome.","authors":"Kei Nakayama, Yumiko Obayashi, Leo Munechika, Shin-Ichi Kitamura, Tetsuya Yanagida, Miho Honjo, Shoko Murakami, Euichi Hirose","doi":"10.3354/dao03801","DOIUrl":"https://doi.org/10.3354/dao03801","url":null,"abstract":"<p><p>Soft tunic syndrome is an infectious disease caused by the flagellate Azumiobodo hoyamushi, which severely damages the aquaculture of the edible ascidian Halocynthia roretzi. Tunic is a cellulosic extracellular matrix entirely covering the body in ascidians and other tunicates, and its dense cuticle layer covers the tunic surface as a physical barrier against microorganisms. When the tunic of intact H. roretzi individuals was cut into strips, electron-dense fibers (DFs) appeared on the cut surface of the tunic matrix and aggregated to regenerate a new cuticular layer in seawater within a few days. DF formation was partially or completely inhibited in individuals with soft tunic syndrome, and DF formation was also inhibited by the presence of some proteases, indicating the involvement of proteolysis in the process of tunic softening as well as cuticle regeneration. Using pure cultures of the causative flagellate A. hoyamushi, the expression of protease genes and secretion of some proteases were confirmed by RNA-seq analysis and a 4-methylcoumaryl-7-amide substrate assay. Some of these proteases may degrade proteins in the tunic matrix. These findings suggest that the proteases of A. hoyamushi is the key to understanding the mechanisms of cuticular regeneration inhibition and tunic softening.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141859337","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}
The chytrid Batrachochytrium dendrobatidis (Bd) is a widespread fungus causing amphibian declines across the globe. Although data on Bd occurrence in Eastern Europe are scarce, a recent species distribution model (SDM) for Bd reported that western and north-western parts of Ukraine are highly suitable to the pathogen. We verified the SDM-predicted range of Bd in Ukraine by sampling amphibians across the country and screening for Bd using qPCR. A total of 446 amphibian samples (tissue and skin swabs) from 11 species were collected from 36 localities. We obtained qPCR-positive results for 33 samples including waterfrogs (Pelophylax esculentus complex) and fire- and yellow-bellied toads (Bombina spp.) from 8 localities. We found that Bd-positive localities had significantly higher predicted Bd habitat suitability than sites that were pathogen-free. Amplification and sequencing of the internal transcribed spacer (ITS) region of samples with the highest Bd load revealed matches with ITS haplotypes of the globally distributed BdGPL strain, and a single case of the BdASIA-2/BdBRAZIL haplotype. We found that Bd was non-randomly distributed across Ukraine, with infections present in the western and north-central forested peripheries of the country with a relatively cool, moist climate. On the other hand, our results suggest that Bd is absent or present in low abundance in the more continental central, southern and eastern regions of Ukraine, corroborating the model-predicted distribution of chytrid fungus. These areas could potentially serve as climatic refugia for Bd-susceptible amphibian hosts.
{"title":"Countrywide screening supports model-based predictions of the distribution of Batrachochytrium dendrobatidis in Ukraine.","authors":"Joanna Jakóbik, Mykola Drohvalenko, Eduardo Fernandez Melendez, Emilia Kępa, Oleksandra Klynova, Anna Fedorova, Oleksii Korshunov, Oleksii Marushchak, Oksana Nekrasova, Natalia Suriadna, Nazar Smirnov, Oksana Tkachenko, Andrii Tupikov, Christophe Dufresnes, Oleksandr Zinenko, Maciej Pabijan","doi":"10.3354/dao03802","DOIUrl":"https://doi.org/10.3354/dao03802","url":null,"abstract":"<p><p>The chytrid Batrachochytrium dendrobatidis (Bd) is a widespread fungus causing amphibian declines across the globe. Although data on Bd occurrence in Eastern Europe are scarce, a recent species distribution model (SDM) for Bd reported that western and north-western parts of Ukraine are highly suitable to the pathogen. We verified the SDM-predicted range of Bd in Ukraine by sampling amphibians across the country and screening for Bd using qPCR. A total of 446 amphibian samples (tissue and skin swabs) from 11 species were collected from 36 localities. We obtained qPCR-positive results for 33 samples including waterfrogs (Pelophylax esculentus complex) and fire- and yellow-bellied toads (Bombina spp.) from 8 localities. We found that Bd-positive localities had significantly higher predicted Bd habitat suitability than sites that were pathogen-free. Amplification and sequencing of the internal transcribed spacer (ITS) region of samples with the highest Bd load revealed matches with ITS haplotypes of the globally distributed BdGPL strain, and a single case of the BdASIA-2/BdBRAZIL haplotype. We found that Bd was non-randomly distributed across Ukraine, with infections present in the western and north-central forested peripheries of the country with a relatively cool, moist climate. On the other hand, our results suggest that Bd is absent or present in low abundance in the more continental central, southern and eastern regions of Ukraine, corroborating the model-predicted distribution of chytrid fungus. These areas could potentially serve as climatic refugia for Bd-susceptible amphibian hosts.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141859336","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}
Carla I Rivera-Pérez, Antonio A Mignucci-Giannoni, Mark A Freeman, Juan M Orcera-Iglesias, Lesly J Cabrias-Contreras, Michelle M Dennis
Five adult Greater Caribbean manatees Trichechus manatus manatus were found stranded on various coasts of Puerto Rico; 2 stranded alive and 3 stranded dead. Clinical signs observed in live-stranded manatees included emaciation, weakness, bradypnea, arrhythmia, and nasal mucus discharge. Postmortem examinations revealed serosanguinous, mucohemorrhagic, or suppurative exudate in bronchi associated with luminal adult Pulmonicola cochleotrema (range: 18-182 trematodes), accompanied by pulmonary abscesses in 2 cases. Histologically, we observed eosinophilic bronchopneumonia of varying severity (n = 4) and chronic erosive to eosinophilic tracheobronchitis (n = 4) with squamous metaplasia (n = 3) and intralesional trematodes and eggs. The trematode identity was confirmed and compared through molecular analysis for the amplified 18S rDNA fragment. Comorbidities included enteric chiorchosis (n = 5), gastric heterocheilosis (n = 4), malnutrition (n = 4), trauma related to watercraft collision (n = 3), systemic toxoplasmosis (n = 1), acute bacterial peritonitis (n = 1), and interstitial nephritis (n = 1), suggesting that immunosuppression was a predisposing factor for lower respiratory tract pulmonicolosis. Based on lesion severity, clinical signs, and the presence and absence of other findings to explain death, this condition was considered the primary cause of death in 1 manatee, a contributory cause of death in 3 manatees, and an incidental finding in 1 individual. These clinicopathological descriptions will facilitate the diagnosis and clinical management of pulmonicolosis in T. manatus, a species endangered with extinction.
{"title":"Verminous bronchitis and pneumonia by nasal trematodes in Greater Caribbean manatees from Puerto Rico.","authors":"Carla I Rivera-Pérez, Antonio A Mignucci-Giannoni, Mark A Freeman, Juan M Orcera-Iglesias, Lesly J Cabrias-Contreras, Michelle M Dennis","doi":"10.3354/dao03800","DOIUrl":"https://doi.org/10.3354/dao03800","url":null,"abstract":"<p><p>Five adult Greater Caribbean manatees Trichechus manatus manatus were found stranded on various coasts of Puerto Rico; 2 stranded alive and 3 stranded dead. Clinical signs observed in live-stranded manatees included emaciation, weakness, bradypnea, arrhythmia, and nasal mucus discharge. Postmortem examinations revealed serosanguinous, mucohemorrhagic, or suppurative exudate in bronchi associated with luminal adult Pulmonicola cochleotrema (range: 18-182 trematodes), accompanied by pulmonary abscesses in 2 cases. Histologically, we observed eosinophilic bronchopneumonia of varying severity (n = 4) and chronic erosive to eosinophilic tracheobronchitis (n = 4) with squamous metaplasia (n = 3) and intralesional trematodes and eggs. The trematode identity was confirmed and compared through molecular analysis for the amplified 18S rDNA fragment. Comorbidities included enteric chiorchosis (n = 5), gastric heterocheilosis (n = 4), malnutrition (n = 4), trauma related to watercraft collision (n = 3), systemic toxoplasmosis (n = 1), acute bacterial peritonitis (n = 1), and interstitial nephritis (n = 1), suggesting that immunosuppression was a predisposing factor for lower respiratory tract pulmonicolosis. Based on lesion severity, clinical signs, and the presence and absence of other findings to explain death, this condition was considered the primary cause of death in 1 manatee, a contributory cause of death in 3 manatees, and an incidental finding in 1 individual. These clinicopathological descriptions will facilitate the diagnosis and clinical management of pulmonicolosis in T. manatus, a species endangered with extinction.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141859310","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}