{"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":"159 ","pages":"15-27"},"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
{"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":"159 ","pages":"49-63"},"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}
Peter Smith, Elizabeth Buba, Andrew P Desbois, Alexandra Adams, David Verner-Jeffreys, Andrew Joseph, Edel Light, Laëtitia Le Devendec, Eric Jouy, Emeline Larvor, Pierre-Marie Boitard, Matthieu Jamin, Nicolas Keck, Alain Le Breton, Benoit Thuillier, Christian Ravaille, Thierry Morin, Sandrine Baron
{"title":"Setting epidemiological cut-off values relevant to MIC and disc diffusion data for Aeromonas salmonicida generated by a standard method.","authors":"Peter Smith, Elizabeth Buba, Andrew P Desbois, Alexandra Adams, David Verner-Jeffreys, Andrew Joseph, Edel Light, Laëtitia Le Devendec, Eric Jouy, Emeline Larvor, Pierre-Marie Boitard, Matthieu Jamin, Nicolas Keck, Alain Le Breton, Benoit Thuillier, Christian Ravaille, Thierry Morin, Sandrine Baron","doi":"10.3354/dao03798","DOIUrl":"https://doi.org/10.3354/dao03798","url":null,"abstract":"<p><p>The Clinical and Laboratory Standards Institute has published epidemiological cut-off values for susceptibility data generated at 22°°C and read after 44-48 h for florfenicol, oxolinic acid and oxytetracycline against Aeromonas salmonicida. The cut-off values for the minimum inhibitory concentration (MIC) and disc diffusion were derived from data obtained by 1 laboratory and 2 laboratories respectively. The present work reports the generation of susceptibility data from additional laboratories and the calculation of provisional cut-off values from aggregations of these data with previously published data. With respect to MIC data, the provisional cut-off values, derived from aggregations of the data from 4 laboratories, were ≤4 µg ml-1 for florfenicol, ≤0.0625 µg ml-1 for oxolinic acid and ≤1 µg ml-1 for oxytetracycline. For disc diffusion data, the provisional cut-off values derived from aggregations of the data from 5 laboratories were ≥30 mm for florfenicol, ≥32 mm for oxolinic acid and ≥25 mm for oxytetracycline. In addition, a cut-off value of ≥29 mm for ampicillin was derived from the aggregation of data from 4 laboratories.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"159 ","pages":"29-35"},"PeriodicalIF":1.1,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141859338","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}
Laura A Brannelly, Preeti Sharma, Sofia Ballesteros, Alexander S Wendt
{"title":"Voriconazole successfully treats chytridiomycosis in frogs.","authors":"Laura A Brannelly, Preeti Sharma, Sofia Ballesteros, Alexander S Wendt","doi":"10.3354/dao03795","DOIUrl":"https://doi.org/10.3354/dao03795","url":null,"abstract":"<p><p>Chytridiomycosis is a devastating disease and is a key cause of amphibian population declines around the world. Despite active research on this amphibian disease system for over 2 decades, we still do not have treatment methods that are safe and that can be broadly used across species. Here, we show evidence that voriconazole is a successful method of treatment for 1 species of amphibian in captivity and that this treatment could offer benefits over other treatment options like heat or itraconazole, which are not able to be used for all species and life stages. We conducted 2 treatments of chytridiomycosis using voriconazole. The treatment was effective and resulted in 100% pathogen clearance, and mortality ceased. Additionally, treating frogs with voriconazole requires less handling than treatment methods like itraconazole and requires no specialized equipment, like heat treatment. We highlight that clinical treatment trials should be conducted to identify an optimum dosage and treatment time and that trials should test whether this treatment is safe and effective for tadpoles and other species.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"159 ","pages":"1-7"},"PeriodicalIF":1.1,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141579204","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":"The first intermediate host of the invasive frog trematode Glypthelmins quieta in Japan.","authors":"Eriko Ansai, Masato Nitta, Takumi Saito, Yosuke Kojima, Tsukasa Waki","doi":"10.3354/dao03799","DOIUrl":"https://doi.org/10.3354/dao03799","url":null,"abstract":"<p><p>Glypthelmins quieta is a frog trematode native to North and Central America. This trematode was recently detected in Japan in the American bullfrog Lithobates catesbeianus, which was introduced from North America to Japan. As the first intermediate host of G. quieta, typically a snail, has not yet been identified in Japan, we conducted a snail survey in eastern Japan to screen for an intermediate host using DNA barcoding based on the nuclear 28S ribosomal RNA and mitochondrial cytochrome c oxidase subunit 1. We sampled 3 different snail species, Orientogalba ollula, Physella acuta, and Sinotaia quadrata histrica (157 individuals in total), and only the freshwater snail Physella acuta, which is also believed to have been introduced from North America to Japan, had sporocysts of G. quieta in its hepatopancreas. The introduction of the intermediate and definitive hosts from North America may have facilitated the invasion of G. quieta into Japan.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"159 ","pages":"9-14"},"PeriodicalIF":1.1,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141579203","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":"Pennella balaenoptera actively select injured cetacean skin as attachment sites, making them potentially useful forensic tags.","authors":"O Chaieb, S Ten, F J Aznar","doi":"10.3354/dao03796","DOIUrl":"https://doi.org/10.3354/dao03796","url":null,"abstract":"<p><p>Cetaceans harbor multiple epibionts on their external surface, and these attach to particular microhabitats. Understanding what drives the selection of attachment sites is relevant for refining the use of epibionts as indicators of their hosts. We report on about 100 females of the mesoparasitic copepod Pennella balaenoptera attached to a dead Cuvier's beaked whale Ziphius cavirostris stranded in Tunisia (western Mediterranean); the first report of P. balaenoptera in this country. The copepods were exclusively attached to numerous incisive, likely anthropogenic, wounds found on the host's skin. This finding suggests that newly recruited females may actively seek skin areas where physical penetration is facilitated; a factor that may help explain patterns of microhabitat selection by Pennella spp., and perhaps other pennellids, on their hosts. The estimated age of parasitization by P. balaenoptera (supported by age estimations of the co-occurring epibiotic barnacle Conchoderma virgatum) also suggests that the cetacean host likely survived these injuries, at least initially, and the presumed cause of death was starvation due to entanglement in a fishing net.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"158 ","pages":"195-200"},"PeriodicalIF":1.1,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141455882","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}
Håvard Bjørgen, Malin Brimsholm, Morten Lund, Maria K Dahle, Espen Rimstad, Erling Olaf Koppang
{"title":"Red and melanized focal changes in the white skeletal muscle of farmed rainbow trout Oncorhynchus mykiss.","authors":"Håvard Bjørgen, Malin Brimsholm, Morten Lund, Maria K Dahle, Espen Rimstad, Erling Olaf Koppang","doi":"10.3354/dao03797","DOIUrl":"https://doi.org/10.3354/dao03797","url":null,"abstract":"<p><p>Fillet discoloration by red and melanized focal changes (RFCs and MFCs) is common in farmed Atlantic salmon Salmo salar. In farmed rainbow trout Oncorhynchus mykiss, similar changes have been noted, but their prevalence and histological characteristics have not been investigated. Thus, we conducted a study encompassing 1293 rainbow trout from 3 different farm sites in Norway, all examined at the time of slaughter. Both macroscopic and histological assessments of the changes were performed. Reverse transcription (RT)-qPCR analyses and in situ hybridization (ISH) were used to detect the presence and location, respectively, of potential viruses. Only 1 RFC was detected in a single fillet, while the prevalence of MFCs ranged from 1.46 to 6.47% between populations. The changes were predominantly localized in the cranioventral region of the fillet. Histological examinations unveiled necrotic myocytes, fibrosis, and regeneration of myocytes. Melano-macrophages were found in the affected areas and in myoseptal adipose tissue. Organized granulomas were observed in only 1 fish. Notably, the presence of inflammatory cells, including melano-macrophages, appeared lower compared to what has been previously documented in Atlantic salmon MFCs. Instead, fibrosis and regeneration dominated. RT-qPCR and ISH revealed the presence of piscine orthoreovirus 1 (PRV-1) and salmonid alphavirus (SAV) in skeletal muscle. However, these viruses were not consistently associated with lesioned areas, contrasting previous findings in Atlantic salmon. In conclusion, rainbow trout develop MFCs of a different character than farmed Atlantic salmon, and we speculate whether the observed pathological differences are contributing to their reduced occurrence in farmed rainbow trout.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"158 ","pages":"201-213"},"PeriodicalIF":1.1,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141455883","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":"Pathogenicity associated with an infestation of the marine leech parasite Pterobdella arugamensis in farmed fish.","authors":"Beng Chu Kua, Yoon Yau Leaw","doi":"10.3354/dao03794","DOIUrl":"https://doi.org/10.3354/dao03794","url":null,"abstract":"<p><p>The marine leech Pterobdella arugamensis is a hematophagous parasite, and the extent of injury to the host largely depends on the number of attached leeches. This study aimed to assess the pathogenicity of marine leeches in Asian seabass (Lates calcarifer) and tiger grouper (Epinephelus fuscoguttatus) fingerlings under laboratory conditions. Five groups of healthy Asian seabass and tiger grouper were exposed to varying numbers of marine leeches (0, 1, 10, 30, or 70 per fish) for 7 d. Infested Asian seabass and tiger grouper both showed pathological changes even with only 1 leech, manifesting as clinical signs like haemorrhages. The cumulative mortality at 7 d post-exposure (dpe) was 11 or 33% for Asian seabass infested with 1 or 10 marine leeches, respectively. Fish with 30 or 70 marine leeches showed higher rates of mortality (56%). A similar trend was seen in tiger grouper, with mortality rates reaching 78% in fish with 30 or 70 marine leeches, and 56 or 33% in fish with 10 leeches or 1 leech, respectively. Factorial analysis of mortality after 7 dpe between both species showed significant differences (2-way ANOVA p = 0.001) when exposed to varying numbers of marine leeches. The haematocrit values differed significantly between Asian seabass or tiger grouper infested with either 0 or 1 marine leech and those infested with 10, 30, or 70 marine leeches (1-way ANOVA, p = 0.0001). This suggests that marine leech infestation has a measurable impact on both species. Consequently, fish farmers should promptly address leech infestation upon discovery in their cages.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"158 ","pages":"179-184"},"PeriodicalIF":1.4,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141310328","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":"Infestation of Lithodes santolla by Eremitione tuberculata: spatial and temporal variations in parasite prevalence and effect on host growth.","authors":"Julia Soledad Colombo, Martín Varisco","doi":"10.3354/dao03792","DOIUrl":"10.3354/dao03792","url":null,"abstract":"<p><p>The southern king crab (SKC) Lithodes santolla is a crustacean parasitised by the bopyrid Eremitione tuberculata. This study aimed to analyse spatial and temporal variations in E. tuberculata prevalence in the juvenile SKC population of San Jorge Gulf (SJG) and adjacent waters (Argentine Patagonia), and evaluate the effects of the parasite on SKC juveniles to improve our understanding of its impact as a disease on SKC health condition. Moult increment and body weight were compared between parasitised and unparasitised individuals. The prevalence of E. tuberculata in SKC juveniles varied both spatially and temporally. In the south of SJG, the prevalence was 54.5% (n = 11). Temporal prevalence analysis revealed values lower than 17.4% in mid SJG during May and September 2015. No significant differences were observed in E. tuberculata prevalence between sexes or among seasons. Eremitione tuberculata had a negative effect on SKC growth (lower body dry mass, moult increment and relative increment rate) in parasitised individuals. We hypothesised that the higher prevalence of E. tuberculata in the south SJG could be attributed to the retention of parasite larvae and the presence of the frontal system in this part of the gulf. The temporal variations could reflect host mortality. Our results suggest that bopyrid infestation may have a more important role than previously believed in the dynamics of the SKC population in mid-Patagonia.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"158 ","pages":"185-193"},"PeriodicalIF":1.4,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141310265","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}
C J Schuster, D P Marancik, C E Couch, C Leong, J J Edwards, R M Kaplan, M L Kent
{"title":"A novel neurotropic microsporidium from the swamp guppy Micropoecilia picta from Grenada, West Indies.","authors":"C J Schuster, D P Marancik, C E Couch, C Leong, J J Edwards, R M Kaplan, M L Kent","doi":"10.3354/dao03789","DOIUrl":"https://doi.org/10.3354/dao03789","url":null,"abstract":"<p><p>A novel microsporidium was observed in wild swamp guppies Micropoecilia picta from Levera Pond within Levera National Park Grenada, West Indies. Initial observations indicated similarity with Pseudoloma neurophilia, an important pathogen in zebrafish Danio rerio. P. neurophilia exhibit broad host specifity, including members of the family Poecillidae, and both parasites infect the central nervous system. However, spore morphology and molecular phylogeny based on rDNA showed that the swamp guppy microsporidium (SGM) is distinct from P. neurophilia and related microsporidia (Microsporidium cerebralis and M. luceopercae). Spores of the SGM were smaller than others in the clade (3.6 µm long). Differences were also noted in histology; the SGM formed large aggregates of spores within neural tissues along with a high incidence of numerous smaller aggregates and single spores within the surface tissue along the ventricular spaces that extended submeninx, whereas P. neurophilia and M. cerebralis infect deep into the neuropile and cause associated lesions. Analysis of small subunit ribosomal DNA sequences showed that the SGM was <93% similar to these related microsporidia. Nevertheless, one of 2 commonly used PCR tests for P. neurophilia cross reacted with tissues infected with SGM. These data suggest that there could be other related microsporidia capable of infecting zebrafish and other laboratory fishes that are not being detected by these highly specific assays. Consequently, exclusive use of these PCR tests may not accurately diagnose other related microsporidia infecting animals in laboratory and ornamental fish facilities.</p>","PeriodicalId":11252,"journal":{"name":"Diseases of aquatic organisms","volume":"158 ","pages":"133-141"},"PeriodicalIF":1.4,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141174822","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}