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Mirella da Silva P, Ramos Queiroga F, Dantas Farias N, Tubino Vianna R, Costa Sabry R. Perkinsus spp. Occurrence in South America: A review. J Invertebr Pathol 2024; 204:108108. [PMID: 38621519 DOI: 10.1016/j.jip.2024.108108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 03/04/2024] [Accepted: 03/06/2024] [Indexed: 04/17/2024]
Abstract
Marine mollusk production is increasing worldwide, and this trend is being evidenced in South American countries, where several species of bivalves are produced, exploited, and traded. This activity brings benefits either for the ecosystem, as it is a less impactful and polluting than other aquaculture practices, and to coastal human communities, as it provides food and income. However, emergence of outbreaks by pathogens is a major concern and can put an entire developing sector at risk. Perkinsosis is a disease caused by Perkinsus spp. protozoans that affect mollusks worldwide. In this review we provide information on Perkinsus spp. among bivalves from South America. Infections by these parasites were only reported to date among coastal Atlantic bivalves of Argentina, Uruguay, and Brazil. The vast majority of cases and studies are reported from Brazil. We comprehensively review those results here. Finally, we suggest some considerations for future investigations that may expand our knowledge of these parasites.
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Affiliation(s)
- Patricia Mirella da Silva
- Laboratório de Imunologia e Patologia de Invertebrados (LABIPI), Departamento de Biologia Molecular, Universidade Federal da Paraíba (UFPB), 58051-900, João Pessoa, Paraíba, Brazil.
| | - Fernando Ramos Queiroga
- Laboratoire des Sciences de l'Environnement Marin (LEMAR - UMR 6539 CNRS/UBO/IRD/IFREMER), Institut Universitaire Européen de la Mer (IUEM), 29280 Plouzané, France.
| | - Natanael Dantas Farias
- Laboratório de Imunologia e Patologia de Invertebrados (LABIPI), Departamento de Biologia Molecular, Universidade Federal da Paraíba (UFPB), 58051-900, João Pessoa, Paraíba, Brazil.
| | - Rogério Tubino Vianna
- Laboratório de Parasitologia de Organismos Aquáticos (LABIPOA), Instituto de Ciências Biológicas, Universidade do Rio Grande (FURG), 96203-900, Rio Grande, Rio Grande do Sul, Brazil.
| | - Rachel Costa Sabry
- Instituto Federal de Educação, Ciência e Tecnologia do Ceará (IFCE), 62800-000, Aracati, Ceará, Brazil.
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Kim SH, Bathige SDNK, Jeon HB, Lee D, Choi KS, Kim HJ, Park KI. First report of Perkinsus marinus occurrence associated with wild Pacific oysters Crassostrea gigas from the west coast of Korea. J Invertebr Pathol 2024; 204:108119. [PMID: 38679368 DOI: 10.1016/j.jip.2024.108119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 04/19/2024] [Accepted: 04/25/2024] [Indexed: 05/01/2024]
Abstract
This study reports the occurrence of Perkinsus marinus associated with wild Pacific oyster (Crassostrea gigas) specimens collected along the west coast of Korea. Confirmation of P. marinus presence was achieved by conventional PCR using World Organization of Animal Health (WOAH)-recommended primers that specifically targeted regions of the rDNA locus (ITS1, 5.8S, and ITS2). Sequencing of 10 samples revealed two distinct sequences differing by a single base pair, indicating potential haplotype variability. One sequence closely resembled the P. marinus strain found in Maryland, USA, whereas the other exhibited divergence, indicative of species diversity in the Korean strain, as was evident from the haplotype network analysis. Further validation involved the Ray's Fluid Thioglycollate Medium (RFTM) assay, which initially yielded inconclusive results, possibly due to low infection intensity. Subsequently, RFTM and 2 M NaOH assays conducted on the isolates in the present study, cultured P. marinus cells in standard DMEM/F12 medium, and a positive P. marinus strain (ATCC 50509), revealed characteristic hypnospores of P. marinus upon Lugol's iodine staining. These comprehensive investigations underscore the conclusive confirmation of P. marinus in Korean waters and mark a significant milestone in our understanding of the distribution and characteristics of this parasite in previously unreported regions.
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Affiliation(s)
- Seung-Hyeon Kim
- Department of Aquatic Life Medicine, College of Ocean Science and Technology, Kunsan National University, 558 Daehakro, Gunsan 54150, Republic of Korea
| | - S D N K Bathige
- Department of Aquatic Life Medicine, College of Ocean Science and Technology, Kunsan National University, 558 Daehakro, Gunsan 54150, Republic of Korea; Research Institute of Fisheries in Offshore Wind Farm (RIFO), Kunsan National University, 558 Daehakro, Gunsan 54150, Republic of Korea
| | - Hyung-Bae Jeon
- Department of Aquatic Life Medicine, College of Ocean Science and Technology, Kunsan National University, 558 Daehakro, Gunsan 54150, Republic of Korea; Research Institute of Fisheries in Offshore Wind Farm (RIFO), Kunsan National University, 558 Daehakro, Gunsan 54150, Republic of Korea
| | - Donghyun Lee
- Department of Aquatic Life Medicine, College of Ocean Science and Technology, Kunsan National University, 558 Daehakro, Gunsan 54150, Republic of Korea
| | - Kwang-Sik Choi
- Department of Marine Life Science, Jeju National University, Jeju 63243, Republic of Korea
| | - Hyoun Joong Kim
- Department of Aquatic Life Medicine, College of Ocean Science and Technology, Kunsan National University, 558 Daehakro, Gunsan 54150, Republic of Korea; Research Institute of Fisheries in Offshore Wind Farm (RIFO), Kunsan National University, 558 Daehakro, Gunsan 54150, Republic of Korea.
| | - Kyung-Il Park
- Department of Aquatic Life Medicine, College of Ocean Science and Technology, Kunsan National University, 558 Daehakro, Gunsan 54150, Republic of Korea; Research Institute of Fisheries in Offshore Wind Farm (RIFO), Kunsan National University, 558 Daehakro, Gunsan 54150, Republic of Korea.
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Johnson FE, Lerch RN, Motavalli PP, Veum KS, Scharf PC. Comparative analysis of three next-generation sequencing techniques to measure nosZ gene abundance in Missouri claypan soils. ENVIRONMENTAL RESEARCH 2024; 249:118346. [PMID: 38311204 DOI: 10.1016/j.envres.2024.118346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 01/16/2024] [Accepted: 01/27/2024] [Indexed: 02/10/2024]
Abstract
Quantitative next-generation sequencing techniques have been critical in gaining a better understanding of microbial ecosystems. In soils, denitrifying microorganisms are responsible for dinitrogen (N2) production. The nosZ gene codes for nitrous oxide reductase, the enzyme facilitating the reduction of nitrous oxide (N2O) to N2. The objectives of this research were to: 1) understand how soil depth influences RNA concentration and nosZ gene abundance; 2) assess the spatial dependence of nosZ gene abundance in two claypan soil fields; and 3) compare and evaluate multiple RNA-based sequencing methods for quantifying nosZ gene abundance in soils in relation to dinitrogen (N2) production. Research sites consisted of two intensively studied claypan soil fields in Central Missouri, USA. Soil cores were collected from two landscape transects across both fields and analyzed for extractable soil RNA at two depths (0-15 cm and 15-30 cm). Measurements of nosZ gene abundance were obtained using real-time quantitative polymerase chain reaction (RT-qPCR), droplet digital polymerase chain reaction (ddPCR), and nanostring sequencing (NS). In both fields, soil RNA concentrations were significantly greater at 0-15 cm depth compared to 15-30 cm. These data indicated low overall soil microbial activity below 15 cm. Due to low quantities of extractable soil RNA in the subsoil, nosZ gene abundance was only determined in the 0-15 cm depth. Sequencing method comparisons of average nosZ gene abundance showed that NS results were constrained to a narrow range and were 10-20-fold lower than ddPCR and RT-qPCR at each landscape position within each field. Droplet digital PCR appears to be the most promising method, as it reflected changes in N2 production across landscape position.
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Affiliation(s)
- Frank E Johnson
- School of Natural Resources, University of Missouri, Columbia, MO, USA; Now at Water Quality and Ecology Research Unit, USDA-ARS, Oxford, MS, USA.
| | - Robert N Lerch
- Cropping Systems and Water Quality Research Unit, USDA-ARS, Columbia, MO, USA
| | - Peter P Motavalli
- School of Natural Resources, University of Missouri, Columbia, MO, USA
| | - Kristen S Veum
- Cropping Systems and Water Quality Research Unit, USDA-ARS, Columbia, MO, USA
| | - Peter C Scharf
- Division of Plant Sciences and Technology, University of Missouri, Columbia, MO, USA
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Stasse A, Lee BY, Brown B. Haplosporidium nelsoni and Perkinsus marinus occurrence in waters of Great Bay Estuary, New Hampshire. DISEASES OF AQUATIC ORGANISMS 2024; 158:75-80. [PMID: 38661139 DOI: 10.3354/dao03787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
In Great Bay Estuary, New Hampshire, USA, Haplosporidium nelsoni and Perkinsus marinus are 2 active pathogens of the eastern oyster Crassostrea virginica (Gmelin), that cause MSX (multinucleated sphere with unknown affinity 'X') and dermo mortalities, respectively. Whereas studies have quantified infection intensities in oyster populations and determined whether these parasites exist in certain planktonic organisms, no studies thus far have examined both infectious agents simultaneously in water associated with areas that do and do not have oyster populations. As in other estuaries, both organisms are present in estuarine waters throughout the Bay, especially during June through November, when oysters are most active. Waters associated with oyster habitats had higher, more variable DNA concentrations from these pathogenic organisms than waters at a non-oyster site. This finding allows for enhanced understanding of disease-causing organisms in New England estuaries, where oyster restoration is a priority.
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Affiliation(s)
- Alyssa Stasse
- Ecological Genetics Laboratory, Department of Biological Sciences, University of New Hampshire, 38 Academic Way, Durham, NH 03824, USA
| | - Bo-Young Lee
- Ecological Genetics Laboratory, Department of Biological Sciences, University of New Hampshire, 38 Academic Way, Durham, NH 03824, USA
| | - Bonnie Brown
- Ecological Genetics Laboratory, Department of Biological Sciences, University of New Hampshire, 38 Academic Way, Durham, NH 03824, USA
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Kim S, Cho M, Yoo J, Park BS. Application of a Quantitative PCR to Investigate the Distribution and Dynamics of Two Morphologically Similar Species, Karenia mikimotoi and K. papilionacea (Dinophyceae) in Korean Coastal Waters. Toxins (Basel) 2023; 15:469. [PMID: 37505738 PMCID: PMC10467055 DOI: 10.3390/toxins15070469] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 07/06/2023] [Accepted: 07/17/2023] [Indexed: 07/29/2023] Open
Abstract
Species of the marine dinoflagellate genus Karenia are known to produce various potent biotoxins and can form noxious blooms that cause mass mortalities of fish and shellfish. To date, harmful blooms of the species K. mikimotoi have been reported in Korea, but K. papilionacea was recently recorded off the southern coast of Korea. Here, we developed a quantitative real-time PCR (qRT-PCR) assay with specific primer pairs for the accurate detection and quantification of these two similar-looking unarmored species, K. mikimotoi and K. papilionacea, and investigated their distribution and dynamics in Korean coastal waters. Overall, K. papilionacea had not only a wider distribution, but also higher cell abundances (15-2553 cells L-1) than K. mikimotoi (3-122 cells L-1) in surface waters. Of 18 sampling sites, the two Karenia species were found to coexist at two sites. During monitoring at a fixed station (S5), K. papilionacea was generally predominant over K. mikimotoi; however, the two species exhibited similar dynamics and occasionally co-occurred. Both Karenia species showed similar physiological responses to temperature and salinity, requiring similar conditions for optimum growth. These results suggest that blooms of the two species may co-occur and induce a synergistic adverse effect on marine environments.
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Affiliation(s)
- Sunju Kim
- Major of Oceanography, Division of Earth Environmental System Science, Pukyong National University, Busan 48513, Republic of Korea; (M.C.); (J.Y.)
| | - Minji Cho
- Major of Oceanography, Division of Earth Environmental System Science, Pukyong National University, Busan 48513, Republic of Korea; (M.C.); (J.Y.)
| | - Jiae Yoo
- Major of Oceanography, Division of Earth Environmental System Science, Pukyong National University, Busan 48513, Republic of Korea; (M.C.); (J.Y.)
| | - Bum Soo Park
- Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 04763, Republic of Korea
- Research Institute for Convergence of Basic Science, Hanyang University, Seoul 04763, Republic of Korea
- Hanyang Institute of Bioscience and Biotechnology, Hanyang University, Seoul 04763, Republic of Korea
- Hanyang Institute of Advanced BioConvergence, Hanyang University, Seoul 04763, Republic of Korea
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Zhang X, Huang BW, Zheng YD, Xin LS, Chen WB, Yu T, Li C, Wang CM, Bai CM. Identification and Characterization of Infectious Pathogens Associated with Mass Mortalities of Pacific Oyster ( Crassostrea gigas) Cultured in Northern China. BIOLOGY 2023; 12:759. [PMID: 37372044 DOI: 10.3390/biology12060759] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/10/2023] [Accepted: 05/19/2023] [Indexed: 06/29/2023]
Abstract
The Pacific oyster (Crassostrea gigas) aquaculture industry increased rapidly in China with the introduction and promotion of triploid oysters in recent years. Mass mortalities affecting different life stages of Pacific oysters emerged periodically in several important production areas of Northern China. During 2020 and 2021, we conducted a passive two-year investigation of infectious pathogens linked to mass mortality. Ostreid herpesvirus-1 (OsHV-1) was detected to be associated with mass mortalities of hatchery larvae, but not juveniles and adults in the open sea. Protozoan parasites, such as Marteilia spp., Perkinsus spp. and Bonamia spp. were not detected. Bacterial isolation and identification revealed that Vibrio natriegens and Vibrio alginolyticus were the most frequently (9 out of 13) identified two dominant bacteria associated with mass mortalities. Pseudoalteromonas spp. was identified as the dominant bacteria in three mortality events that occurred during the cold season. Further bacteriological analysis was conducted on two representative isolates of V. natriegens and V. alginolyticus, designated as CgA1-1 and CgA1-2. Multisequence analysis (MLSA) showed that CgA1-1 and CgA1-2 were closely related to each other and nested within the Harveyi clade. Bacteriological investigation revealed faster growth, and more remarkable haemolytic activity and siderophore production capacity at 25 °C than at 15 °C for both CgA1-1 and CgA1-2. The accumulative mortalities of experimental immersion infections were also higher at 25 °C (90% and 63.33%) than at 15 °C (43.33% and 33.33%) using both CgA1-1 and CgA1-2, respectively. Similar clinical and pathological features were identified in samples collected during both naturally and experimentally occurring mortalities, such as thin visceral mass, discolouration, and connective tissue and digestive tube lesions. The results presented here highlight the potential risk of OsHV-1 to hatchery production of larvae, and the pathogenic role of V. natriegens and V. alginolyticus during mass mortalities of all life stages of Pacific oysters in Northern China.
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Affiliation(s)
- Xiang Zhang
- Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture, Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China
| | - Bo-Wen Huang
- Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture, Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China
| | - Yu-Dong Zheng
- Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture, Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China
| | - Lu-Sheng Xin
- Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture, Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Wen-Bo Chen
- Dalian Modern Agricultural Production Development Service Center, Dalian 116023, China
| | - Tao Yu
- Changdao Enhancement and Experiment Station, Chinese Academy of Fishery Sciences, Yantai 265800, China
| | - Chen Li
- Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture, Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Chong-Ming Wang
- Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture, Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Chang-Ming Bai
- Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture, Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
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Chen X, Reece KS, Shields JD. Natural Transmission of Hematodinium perezi in Juvenile Blue Crabs (Callinectes sapidus) in the Laboratory. J Invertebr Pathol 2023; 198:107918. [PMID: 37019353 DOI: 10.1016/j.jip.2023.107918] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 03/15/2023] [Accepted: 03/28/2023] [Indexed: 04/05/2023]
Abstract
Hematodinium perezi is a dinoflagellate endoparasitic in marine crustaceans, primarily decapods. It occurs in juvenile blue crabs, Callinectes sapidus, at high prevalence levels and has severe pathogenic effects in this host. The life history outside the host has not been experimentally investigated and, until now, transmission using dinospores has not been successful. We investigated the natural transmission dynamics of H. perezi in the laboratory using small juvenile crabs, which are highly susceptible to infection in the field, and elevated temperatures, which are known to stimulate dinospore production. Natural water-borne transmission to naïve crabs varied between 7-100% and was not correlated with dinospore densities measured from their aquaria water. Infections appeared to develop quickly in naïve hosts at 25 °C, suggesting that elevated temperatures as seen in the late summer and early autumn have a strong influence on the transmission of H. perezi in natural systems.
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Affiliation(s)
- Xuqing Chen
- Virginia Institute of Marine Science, P.O. Box 1346, 1375 Greate Road, Gloucester Point, VA 23062-1346, USA
| | - Kimberly S Reece
- Virginia Institute of Marine Science, P.O. Box 1346, 1375 Greate Road, Gloucester Point, VA 23062-1346, USA
| | - Jeffrey D Shields
- Virginia Institute of Marine Science, P.O. Box 1346, 1375 Greate Road, Gloucester Point, VA 23062-1346, USA.
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Souza da Rocha C, Costa Sabry R, dos Santos Rocha R, Maggioni R, Vinicius Silva de Araújo B, Julia dos Santos Silva R, Marcelo Azevedo de Paula Antunes J. First record of Perkinsus marinus infecting Crassostrea sp. in Rio Grande do Norte, Brazil, using real-time PCR. J Invertebr Pathol 2023; 198:107917. [PMID: 37004916 DOI: 10.1016/j.jip.2023.107917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 03/15/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023]
Abstract
A pathogen with high virulence potential in some host species, Perkinsus marinus remains a challenge for the ecological integrity of marine ecosystems and the health of bivalve molluscs. This study investigates the occurrence of P. marinus in Crassostrea sp. in estuaries of the Potengi River and the Guaraíras lagoon in Rio Grande do Norte, Brazil. A total of 203 oyster samples that tested positive for Perkinsus sp. in Ray's fluid thioglycollate medium (RFTM) were subjected to species-specific quantitiative PCR, where 61 animals (30.05%) presented amplification graphs with a melting temperature of 80.1 ± 0.6°C matching the positive control. This was the first record of P. marinus in oysters in these estuaries using qPCR as a diagnostic tool.
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Piesz JL, Scro AK, Corbett R, Lundgren KM, Smolowitz R, Gomez-Chiarri M. Development of a multiplex qPCR for the quantification of three protozoan parasites of the eastern oyster Crassostrea virginica. DISEASES OF AQUATIC ORGANISMS 2022; 151:111-121. [PMID: 36300764 DOI: 10.3354/dao03694] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
A multiplex quantitative PCR (qPCR) assay for the simultaneous detection of 3 eastern oyster Crassostrea virginica parasites, Perkinsus marinus, Haplosporidium nelsoni, and H. costale, was developed using 3 different fluorescently labeled hydrolysis probes. The primers and probe from a previously validated singleplex qPCR for P. marinus detection were combined with newly designed primers and probes specific for H. nelsoni and H. costale. The functionality of the multiplex assay was demonstrated on 2 different platforms by the linear relationship of the standard curves and similar cycle threshold (CT) values between parasites. Efficiency of the multiplex qPCR assay on the Roche and BioRad platforms ranged between 93 and 101%. The sensitivity of detection ranged between 10 and 100 copies of plasmid DNA for P. marinus and Haplosporidium spp., respectively. The concordance between the Roche and BioRad platforms in the identification of the parasites P. marinus, H. nelsoni, and H. costale was 91, 97, and 97%, respectively, with a 10-fold increase in the sensitivity of detection of Haplosporidium spp. on the BioRad thermocycler. The concordance between multiplex qPCR and histology for P. marinus, H. nelsoni, and H. costale was 54, 57, and 87%, respectively. Discordances between detection methods were largely related to localized or low levels of infections in oyster tissues, and qPCR was the more sensitive diagnostic. The multiplex qPCR developed here is a sensitive diagnostic tool for the quantification and surveillance of single and mixed infections in the eastern oyster.
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Affiliation(s)
- Jessica L Piesz
- Department of Fisheries, Animal, and Veterinary Science, University of Rhode Island, Kingston, Rhode Island 02881, USA
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Hanrio E, Batley J, Dungan CF, Dang C. Immunoassays and diagnostic antibodies for Perkinsus spp. pathogens of marine molluscs. DISEASES OF AQUATIC ORGANISMS 2021; 147:13-23. [PMID: 34734570 DOI: 10.3354/dao03635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Perkinsus sp. protozoans are parasites of a wide variety of molluscs around the world and are responsible for episodes of mass mortalities and large economic losses for aquaculture industries and fisheries. The first step towards the management of infectious episodes is the reliable detection of Perkinsus species. While historic methods for diagnosis of Perkinsus sp. infections in mollusc hosts include histological, in vitro, molecular-genetic, and immunoassays, antibody-based diagnostic assays may prove most practical with development of improved reagents and techniques. This paper reviews historic developments of antibodies against Perkinsus species, and of diagnostic immunoassays. Thirteen research papers reported the development of antibodies against Perkinsus sp. or their extracellular products, mainly P. olseni and P. marinus. Nine of those tested the cross-reactivity of their antibodies against different life stages or species than the one used as immunogen. While all antibodies raised against trophozoites labelled hypnospores, several antibodies raised against hypnospores did not label trophozoites, suggesting antigenic differences between those cell types. Antibody specificity studies showed that there is antigenic heterogeneity between Perkinsus species and Perkinsus-like organisms, and also that common epitopes occur among Perkinsus species, as well as some dinoflagellates. This review summarizes the current knowledge and aims at helping the future development of Perkinsus species-specific antibodies and immunoassays.
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Affiliation(s)
- Eliot Hanrio
- The University of Western Australia, Crawley 6009, Western Australia, Australia
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Itoïz S, Perennou M, Mouronvalle C, Derelle E, Le Goïc N, Bidault A, de Montaudouin X, Arzul I, Soudant P, Chambouvet A. Development of duplex TaqMan-based real-time PCR assay for the simultaneous detection of Perkinsus olseni and P. chesapeaki in host Manila clam tissue samples. J Invertebr Pathol 2021; 184:107603. [PMID: 33971219 DOI: 10.1016/j.jip.2021.107603] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 04/13/2021] [Accepted: 04/25/2021] [Indexed: 11/28/2022]
Abstract
The aetiological agent Perkinsus olseni is globally recognised as a major threat for shellfish production considering its wide geographical distribution across Asia, Europe, Australia and South America. Another species, Perkinsus chesapeaki, which has never been known to be associated with significant mortality events, was recently detected along French coasts infecting clam populations sporadically in association with P. olseni. Identifying potential cryptic infections affecting Ruditapes philippinarum is essential to develop appropriate host resource management strategies. Here, we developed a molecular method based on duplex real-time quantitative PCR for the simultaneous detection of these two parasites, P. olseni and P. chesapeaki, in the different clam tissues: gills, digestive gland, foot, mantle, adductor muscle and the rest of the soft body. We firstly checked the presence of possible PCR inhibitors in host tissue samples. The qPCR reactions were inhibited depending on the nature of the host organ. The mantle and the rest of the soft body have a high inhibitory effect from threshold of host gDNA concentration of 2 ng.µL-1, the adductor muscle and the foot have an intermediate inhibition of 5 ng.µL-1, and the gills and digestive gland do not show any inhibition of the qPCR reaction even at the highest host gDNA concentration of 20 ng.µL-1. Then, using the gills as a template, the suitability of the molecular technique was checked in comparison with the Ray's Fluid Thioglycolate Medium methodology recommended by the World Organisation for Animal Health. The duplex qPCR method brought new insights and unveiled cryptic infections as the co-occurrence of P. olseni and P. chesapeaki from in situ tissue samples in contrast to the RFTM diagnosis. The development of this duplex qPCR method is a fundamental work to monitor in situ co-infections that will lead to optimised resource management and conservation strategies to deal with emerging diseases.
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Affiliation(s)
- Sarah Itoïz
- Univ Brest, CNRS, IRD, Ifremer, LEMAR, F-29280 Plouzané, France
| | - Morgan Perennou
- Univ Brest, CNRS, IRD, Ifremer, LEMAR, F-29280 Plouzané, France
| | - Clara Mouronvalle
- Univ Brest, CNRS, IRD, Ifremer, LEMAR, F-29280 Plouzané, France; EPHE, PSL Research University, UPVD, CNRS, USR 3278 CRIOBE, Perpignan F-66360, France
| | - Evelyne Derelle
- Univ Brest, CNRS, IRD, Ifremer, LEMAR, F-29280 Plouzané, France
| | - Nelly Le Goïc
- Univ Brest, CNRS, IRD, Ifremer, LEMAR, F-29280 Plouzané, France
| | - Adeline Bidault
- Univ Brest, CNRS, IRD, Ifremer, LEMAR, F-29280 Plouzané, France
| | - Xavier de Montaudouin
- Univ. Bordeaux, CNRS, EPOC, EPHE, UMR 5805, Station Marine, F-33120 Arcachon, France
| | - Isabelle Arzul
- IFREMER, Laboratory of Genetics and Pathology, Av de Mus de Loup-17390, La Tremblade, France
| | - Philippe Soudant
- Univ Brest, CNRS, IRD, Ifremer, LEMAR, F-29280 Plouzané, France.
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12
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Mérou N, Lecadet C, Pouvreau S, Arzul I. An eDNA/eRNA-based approach to investigate the life cycle of non-cultivable shellfish micro-parasites: the case of Bonamia ostreae, a parasite of the European flat oyster Ostrea edulis. Microb Biotechnol 2020; 13:1807-1818. [PMID: 32608578 PMCID: PMC7533330 DOI: 10.1111/1751-7915.13617] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 05/25/2020] [Accepted: 06/02/2020] [Indexed: 12/31/2022] Open
Abstract
Environmental DNA approaches are increasingly used to detect microorganisms in environmental compartments, including water. They show considerable advantages to study non-cultivable microorganisms like Bonamia ostreae, a protozoan parasite inducing significant mortality in populations of flat oyster Ostrea edulis. Although B. ostreae development within the host has been well described, questions remain about its behaviour in the environment. As B. ostreae transmission is direct, seawater appears as an interesting target to develop early detection tools and improve our understanding of disease transmission mechanisms. In this context, we have developed an eDNA/eRNA approach allowing detecting and quantifying B. ostreae 18S rDNA/rRNA as well as monitoring its presence in seawater by real-time PCR. B. ostreae DNA could be detected up to 4 days while RNA could be detected up to 30 days, suggesting a higher sensitivity of the eRNA-based tool. Additionally, more than 90% of shed parasites were no longer detected after 2 days outside the oysters. By allowing B. ostreae detection in seawater, this approach would not only be useful to monitor the presence of the parasite in oyster production areas but also to evaluate the effect of changing environmental factors on parasite survival and transmission.
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Affiliation(s)
- Nicolas Mérou
- Laboratoire de Génétique et Pathologie des Mollusques MarinsIfremerSG2M‐LGPMMAvenue de Mus de Loup17390La TrembladeFrance
| | - Cyrielle Lecadet
- Laboratoire de Génétique et Pathologie des Mollusques MarinsIfremerSG2M‐LGPMMAvenue de Mus de Loup17390La TrembladeFrance
| | - Stéphane Pouvreau
- Laboratoire des Sciences de l'Environnement MarinUMR 6539, Ifremer/UBO/IRD/CNRSIfremer11 Presqu'île du Vivier29840Argenton‐en‐LandunvezFrance
| | - Isabelle Arzul
- Laboratoire de Génétique et Pathologie des Mollusques MarinsIfremerSG2M‐LGPMMAvenue de Mus de Loup17390La TrembladeFrance
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13
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Shea D, Bateman A, Li S, Tabata A, Schulze A, Mordecai G, Ogston L, Volpe JP, Neil Frazer L, Connors B, Miller KM, Short S, Krkošek M. Environmental DNA from multiple pathogens is elevated near active Atlantic salmon farms. Proc Biol Sci 2020; 287:20202010. [PMID: 33081614 PMCID: PMC7661312 DOI: 10.1098/rspb.2020.2010] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The spread of infection from reservoir host populations is a key mechanism for disease emergence and extinction risk and is a management concern for salmon aquaculture and fisheries. Using a quantitative environmental DNA methodology, we assessed pathogen environmental DNA in relation to salmon farms in coastal British Columbia, Canada, by testing for 39 species of salmon pathogens (viral, bacterial, and eukaryotic) in 134 marine environmental samples at 58 salmon farm sites (both active and inactive) over 3 years. Environmental DNA from 22 pathogen species was detected 496 times and species varied in their occurrence among years and sites, likely reflecting variation in environmental factors, other native host species, and strength of association with domesticated Atlantic salmon. Overall, we found that the probability of detecting pathogen environmental DNA (eDNA) was 2.72 (95% CI: 1.48, 5.02) times higher at active versus inactive salmon farm sites and 1.76 (95% CI: 1.28, 2.42) times higher per standard deviation increase in domesticated Atlantic salmon eDNA concentration at a site. If the distribution of pathogen eDNA accurately reflects the distribution of viable pathogens, our findings suggest that salmon farms serve as a potential reservoir for a number of infectious agents; thereby elevating the risk of exposure for wild salmon and other fish species that share the marine environment.
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Affiliation(s)
- Dylan Shea
- Department of Ecology and Evolutionary Biology, University of Toronto, Ontario, Canada
| | - Andrew Bateman
- Department of Ecology and Evolutionary Biology, University of Toronto, Ontario, Canada.,Salmon Coast Field Station, Simoom Sound, British Columbia, Canada.,Pacific Salmon Foundation, Vancouver, British Columbia, Canada
| | - Shaorong Li
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, British Columbia, Canada
| | - Amy Tabata
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, British Columbia, Canada
| | - Angela Schulze
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, British Columbia, Canada
| | - Gideon Mordecai
- Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lindsey Ogston
- Department of Ecology and Evolutionary Biology, University of Toronto, Ontario, Canada
| | - John P Volpe
- School of Environmental Studies, University of Victoria, Victoria, British Columbia, Canada
| | - L Neil Frazer
- Department of Earth Sciences, University of Hawaii at Mānoa, Honolulu, Hawaii, Canada
| | - Brendan Connors
- Institute of Ocean Sciences, Fisheries and Oceans Canada, Sidney, British Columbia, Canada
| | - Kristina M Miller
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, British Columbia, Canada
| | - Steven Short
- Department of Ecology and Evolutionary Biology, University of Toronto, Ontario, Canada.,Department of Biology, University of Toronto Mississauga, Mississauga, British Columbia, Canada
| | - Martin Krkošek
- Department of Ecology and Evolutionary Biology, University of Toronto, Ontario, Canada.,Salmon Coast Field Station, Simoom Sound, British Columbia, Canada
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14
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Istiqomah MA, Hasibuan PAZ, Sumaiyah S, Yusraini E, Oku H, Basyuni M. Anticancer Effects of Polyisoprenoid From Nypa fruticans Leaves by Controlling Expression of p53, EGFR, PI3K, AKT1, and mTOR Genes in Colon Cancer (WiDr) Cells. Nat Prod Commun 2020. [DOI: 10.1177/1934578x20918412] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The current research seeks to examine the anticancer effect of polyisoprenoids from mangrove palm, Nypa fruticans, leaves in WiDr cells by analyzing the cell cycles of cancer and regulating the expression of p53, epidermal growth factor receptor (EGFR), PI3K, AKT1, and mammalian target of rapamycin (mTOR) genes by using the reverse transcription-polymerase chain reaction (RT-PCR). An inhibited cell cycle analysis was conducted using the flow cytometry, and the upregulation or downregulation of the expression of p53, EGFR, PI3K, AKT1, and mTOR genes was obtained using RT-PCR. The data were then statistically analyzed using one-way analysis of variance by a post hoc test, a parametric statistical analysis using Tukey’s honest significant difference. Polyisoprenoids in N. fruticans extracts worked as chemotheraupetic in the G0-G1 cycle is 79.0%, however, with positive control 5-fluorouracil as 88.1% and are carried out by the specific upregulation of the expression of the p53 gene and the downregulation of the expression of the EGFR, PI3K, AKT1, and mTOR genes. This study can also explain the significant pharmacological properties of the leaves of the species N. fruticans that work specifically in the G0-G1 phase to upregulate the expression of the p53 gene and downregulate the expression of the EGFR, PI3K, AKT1, and mTOR genes. This study also revealed polyisoprenoid (100% dolichol), which blocked the growth and development of WiDr colon cancer cells.
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Affiliation(s)
| | | | - Sumaiyah Sumaiyah
- Department of Pharmacology, Faculty of Pharmacy, Universitas Sumatera Utara, Medan, Indonesia
| | - Era Yusraini
- Department of Food Science and Technology, Faculty of Agriculture, Universitas Sumatera Utara, Medan, North Sumatra, Indonesia
| | - Hirosuke Oku
- Molecular Biotechnology Group, Tropical Biosphere Research Center, University of the Ryukyus, Nishihara, Okinawa, Japan
| | - Mohammad Basyuni
- Department of Forestry, Faculty of Forestry, Universitas Sumatera Utara, Medan, Indonesia
- Center of Excellence for Mangrove, Universitas Sumatera Utara, Medan, Indonesia
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15
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Ríos R, Aranguren R, Gastaldelli M, Arcangeli G, Novoa B, Figueras A. Development and validation of a specific real-time PCR assay for the detection of the parasite Perkinsus olseni. J Invertebr Pathol 2019; 169:107301. [PMID: 31794707 DOI: 10.1016/j.jip.2019.107301] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 10/31/2019] [Accepted: 11/29/2019] [Indexed: 11/18/2022]
Abstract
Perkinsus olseni is a protozoan parasite that infects a wide variety of molluscs worldwide, causing economic losses in the aquaculture sector. In the present study, a quantitative PCR (qPCR) assay was developed for the detection and quantification of P. olseni in clam gill tissue and hemolymph (Ruditapes philippinarum and R. decussatus), and the results were compared with those of the standard diagnostic methods recommended by the O.I.E. (World Organisation for Animal Health): Ray's fluid thioglycollate culture method (RFTM), a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay and histopathology. The efficiency, sensitivity and reproducibility of the newly described qPCR assay were also determined. The highest prevalence was detected using the qPCR assay, and the strongest linear correlation was obtained between the RFTM infection levels and the threshold cycle (Ct) number from the gill tissue. Although better results were obtained from gill than from the hemolymph in the qPCR assays, especially with lower infection levels of the parasite, a significant linear correlation was observed between Ct values from the gill and hemolymph. The qPCR assay that was developed in this study showed high sensitivity, specificity and reproducibility for the detection and quantification of P. olseni.
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Affiliation(s)
- R Ríos
- Instituto de Investigaciones Marinas (CSIC), Eduardo Cabello 6, 36208 Vigo, Spain
| | - R Aranguren
- Instituto de Investigaciones Marinas (CSIC), Eduardo Cabello 6, 36208 Vigo, Spain
| | - M Gastaldelli
- Istituto zooprofilattico sperimentale delle Venezie V. le Università, 10 35020 Legnaro (Pd), Italy
| | - G Arcangeli
- Istituto zooprofilattico sperimentale delle Venezie V. le Università, 10 35020 Legnaro (Pd), Italy
| | - B Novoa
- Instituto de Investigaciones Marinas (CSIC), Eduardo Cabello 6, 36208 Vigo, Spain
| | - A Figueras
- Instituto de Investigaciones Marinas (CSIC), Eduardo Cabello 6, 36208 Vigo, Spain.
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16
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Itoh N, Komatsu Y, Maeda K, Hirase S, Yoshinaga T. First discovery of Perkinsus beihaiensis in Mediterranean mussels (Mytilus galloprovincialis) in Tokyo Bay, Japan. J Invertebr Pathol 2019; 166:107226. [DOI: 10.1016/j.jip.2019.107226] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 07/27/2019] [Accepted: 07/29/2019] [Indexed: 11/26/2022]
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17
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Park BS, Kim S, Kim JH, Ho Kim J, Han MS. Dynamics of Amoebophrya parasites during recurrent blooms of the ichthyotoxic dinoflagellate Cochlodinium polykrikoides in Korean coastal waters. HARMFUL ALGAE 2019; 84:119-126. [PMID: 31128796 DOI: 10.1016/j.hal.2019.02.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 01/24/2019] [Accepted: 02/01/2019] [Indexed: 06/09/2023]
Abstract
During the bloom events of the harmful dinoflagellate Cochlodinium polykrikoides in August and October, 2012, infections by two different Amoebophrya species were observed in Korean coastal waters. To investigate the dynamics of the two parasites and their relative impact on the host populations, a quantitative real-time PCR (qPCR) method was applied to detect and quantify the parasites in the free-living and parasitic stages. Each specific primer set of the target species, Amoebophrya sp. 1 and sp. 2 was designed on the large subunit (LSU) and the first internal transcribed spacer (ITS1) of ribosomal RNA (rRNA) gene, respectively. Dynamics of the two Amoebophrya species via qPCR assay showed distinct patterns during the C. polykrikoides bloom events. Amoebophrya sp. 1 showed peaks during both bloom events in August and October with relatively low copies (106 to 107 copies L-1), while Amoebophrya sp. 2 appeared only during the bloom event in October with very high copies (109 to 1010 copies L-1). Overall, the qPCR measurements for the dynamics of two Amoebophrya species in the parasitic stage (> 5 μm fractions) were consistent with parasite prevalence through microscopic observations. Amoebophrya sp. 1 infections were observed during both bloom events in August and October with relatively low parasite prevalence (0.1-1.5%), while Amoebophrya sp. 2 infections were detected only during the bloom event in October with high prevalence (up to 45%). Taken together, Amoebophrya sp. 1 may be a generalist and C. polykrikoides may not be its primary host, while Amoebophrya sp. 2 may be a specialist which can substantially impact host population dynamics.
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Affiliation(s)
- Bum Soo Park
- Department of Life Science, Hanyang University, Seoul 04763, South Korea; Marine Science Institute, The University of Texas at Austin, Port Aransas, TX 78373, USA
| | - Sunju Kim
- Department of Oceanography, Pukyong National University, Busan 48513, South Korea
| | - Joo-Hwan Kim
- Department of Life Science, Hanyang University, Seoul 04763, South Korea; Water Source Management Division, Han River Basin Environmental Office, Hanam, 12902, South Korea
| | - Jin Ho Kim
- Department of Life Science, Hanyang University, Seoul 04763, South Korea; Risk Assessment Research Center, KIOST (Korea Institute of Ocean Science and Technology), Geoje, 53201, South Korea
| | - Myung-Soo Han
- Department of Life Science, Hanyang University, Seoul 04763, South Korea; Research Institute for Natural Sciences, Hanyang University, Seoul 04763, South Korea.
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18
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Real-Time PCR based test for the early diagnosis of Haplosporidium pinnae affecting fan mussel Pinna nobilis. PLoS One 2019; 14:e0212028. [PMID: 30794588 PMCID: PMC6386276 DOI: 10.1371/journal.pone.0212028] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 01/26/2019] [Indexed: 11/19/2022] Open
Abstract
Noble pen shell or fan mussel, Pinna nobilis Linnaeus (1758), protected since 1992, was incorporated into the Spanish Catalogue of Threatened Species (Category: Vulnerable, Royal Decree 139/2011). The status is presently in the process of being catalogued as critically endangered, pending approval by Spanish Government (https://www.mapama.gob.es/es/biodiversidad/participacion-publica/Borrador_OM_situacion_critica.aspx). The International Union for the Conservation of Nature (IUCN) alerted the countries of the Mediterranean basin to the “emergent situation” due to serious mortality events suffered by the fan mussel, putting it in serious risk of extinction. Thus, emergency actions have been implemented by Spanish authorities in which several research institutes from all over the country are involved. The parasite, Haplosporidium pinnae, was recently characterized by histology, TEM, SEM and molecular biology techniques and it was considered responsible for the mass mortality of P. nobilis in the Mediterranean Sea. In this context, the aim of this study has been to develop species-specific quantitative PCR (qPCR) protocol carrying out a fast, specific and effective molecular diagnose of H. pinnae. In this sense, the detection limit for qPCR was equal to 30 copies of SSU rDNA / ng of DNA using plasmid alone and when 100ng DNA of non-infected oyster were added. The qPCR assay revealed that 94% of the 32 analysed mantle tissues of fan mussel were infected by H. pinnae, showing a high sensitivity and specificity for its detection (100% if we don't consider negative and too much degraded samples). This technique will allow us to make quicker follow-ups of the disease, allowing us to get a better understanding of its evolution in order to help in the rescue of P. nobilis populations
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19
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Lau YT, Gambino L, Santos B, Pales Espinosa E, Allam B. Transepithelial migration of mucosal hemocytes in Crassostrea virginica and potential role in Perkinsus marinus pathogenesis. J Invertebr Pathol 2018. [PMID: 29518429 DOI: 10.1016/j.jip.2018.03.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We have recently described the presence of hemocytes associated with mucus covering the pallial organs (mantle, gills, and body wall) 3 of the eastern oyster Crassostrea virginica. These hemocytes, hereby designated "pallial hemocytes" share common general characteristics with circulating hemocytes but also display significant differences particularly in their cell surface epitopes. The specific location of pallial hemocytes as peripheral cells exposed directly to the marine environment confers them a putative sentinel role. The purpose of this study was to gain a better understanding of the source of these pallial hemocytes by evaluating possible exchanges between circulatory and pallial hemocyte populations and whether these exchanges are regulated by pathogen exposure. Bi-directional transepithelial migrations of hemocytes between pallial surfaces and the circulatory system were monitored using standard cell tracking approaches after staining with the vital fluorescent dye carboxyfluorescein diacetate succinimidyl ester (CFSE) in conjunction with fluorescent microscopy and flow cytometry. Results showed bi-directional migration of hemocytes between both compartments and suggest that hemocyte migration from the pallial mucus layer to the circulatory system may occur at a greater rate compared to migration from the circulatory system to the pallial mucus layer, further supporting the role of pallial hemocytes as sentinel cells. Subsequently, the effect of the obligate parasite Perkinsus marinus and the opportunistic pathogen Vibrio alginolyticus on transepithelial migration of oyster hemocytes was investigated. Results showed an increase in hemocyte migration in response to P. marinus exposure. Furthermore, P. marinus cells were acquired by pallial hemocytes before being visible in underlying tissues and the circulatory system suggesting that this parasite could use pallial hemocytes as a vehicle facilitating its access to oyster tissues. These results are discussed in light of new evidence highlighting the role of oyster pallial organs as a portal for the initiation of P. marinus infections in oysters.
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Affiliation(s)
- Yuk-Ting Lau
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Laura Gambino
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Bianca Santos
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | | | - Bassem Allam
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA.
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20
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Pagenkopp Lohan KM, Hill-Spanik KM, Torchin ME, Fleischer RC, Carnegie RB, Reece KS, Ruiz GM. Phylogeography and connectivity of molluscan parasites: Perkinsus spp. in Panama and beyond. Int J Parasitol 2018; 48:135-144. [DOI: 10.1016/j.ijpara.2017.08.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 07/31/2017] [Accepted: 08/05/2017] [Indexed: 11/16/2022]
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21
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Polinski MP, Meyer GR, Lowe GJ, Abbott CL. Seawater detection and biological assessments regarding transmission of the oyster parasite Mikrocytos mackini using qPCR. DISEASES OF AQUATIC ORGANISMS 2017; 126:143-153. [PMID: 29044044 DOI: 10.3354/dao03167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Mikrocytos mackini is an intracellular parasite of oysters and causative agent of Denman Island disease in Pacific oysters Crassostrea gigas. Although M. mackini has been investigated for decades, its natural mode of transmission, mechanism for host entry, and environmental stability are largely unknown. We explored these biological characteristics of M. mackini using a recently described quantitative PCR (qPCR) assay. We detected M. mackini in the flow-through tank water of experimentally infected oysters and during disease remission in host tissues following 6 wk of elevated water temperature. Waterborne exposure of oysters to M. mackini further confirmed the potential for extracellular seawater transmission of this parasite and also identified host gill to have the highest early and continued prevalence for M. mackini DNA compared to stomach, mantle, labial palps, or adductor muscle samples. However, infections following waterborne challenge were slow to develop despite a substantial exposure (>106 M. mackini l-1 for 24 h), and further investigation demonstrated that M. mackini occurrence and infectivity severely declined following extracellular seawater incubation of more than 24 h. This study demonstrates a potential for using qPCR to monitor M. mackini in wild or farmed oyster populations during periods of disease remission or from environmental seawater samples. This work also suggests that gill tissues may provide a primary site for waterborne entry and possibly shedding of M. mackini in oysters. Further, although extracellular seawater transmission of M. mackini was possible, poor environmental stability and infection efficiency likely restricts the geographic transmission of M. mackini between oysters in natural environs and may help to explain localized areas of infection.
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Affiliation(s)
- Mark P Polinski
- Fisheries and Oceans Canada, Pacific Biological Station, 3190 Hammond Bay Road, Nanaimo, BC V9T 6N7, Canada
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22
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Carrasco N, Voorbergen-Laarman M, Lacuesta B, Furones D, Engelsma MY. Application of a competitive real time PCR for detection of Marteilia refringens genotype “O” and “M” in two geographical locations: The Ebro Delta, Spain and the Rhine-Meuse Delta, the Netherlands. J Invertebr Pathol 2017; 149:51-55. [DOI: 10.1016/j.jip.2017.07.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 07/06/2017] [Accepted: 07/17/2017] [Indexed: 10/19/2022]
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Pathogenic lineage of Perkinsea associated with mass mortality of frogs across the United States. Sci Rep 2017; 7:10288. [PMID: 28860470 PMCID: PMC5579288 DOI: 10.1038/s41598-017-10456-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 08/08/2017] [Indexed: 01/31/2023] Open
Abstract
Emerging infectious diseases such as chytridiomycosis and ranavirus infections are important contributors to the worldwide decline of amphibian populations. We reviewed data on 247 anuran mortality events in 43 States of the United States from 1999–2015. Our findings suggest that a severe infectious disease of tadpoles caused by a protist belonging to the phylum Perkinsea might represent the third most common infectious disease of anurans after ranavirus infections and chytridiomycosis. Severe Perkinsea infections (SPI) were systemic and led to multiorganic failure and death. The SPI mortality events affected numerous anuran species and occurred over a broad geographic area, from boreal to subtropical habitats. Livers from all PCR-tested SPI-tadpoles (n = 19) were positive for the Novel Alveolate Group 01 (NAG01) of Perkinsea, while only 2.5% histologically normal tadpole livers tested positive (2/81), suggesting that subclinical infections are uncommon. Phylogenetic analysis demonstrated that SPI is associated with a phylogenetically distinct clade of NAG01 Perkinsea. These data suggest that this virulent Perkinsea clade is an important pathogen of frogs in the United States. Given its association with mortality events and tendency to be overlooked, the potential role of this emerging pathogen in amphibian declines on a broad geographic scale warrants further investigation.
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Carnegie RB, Arzul I, Bushek D. Managing marine mollusc diseases in the context of regional and international commerce: policy issues and emerging concerns. Philos Trans R Soc Lond B Biol Sci 2016; 371:rstb.2015.0215. [PMID: 26880834 DOI: 10.1098/rstb.2015.0215] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Marine mollusc production contributes to food and economic security worldwide and provides valuable ecological services, yet diseases threaten these industries and wild populations. Although the infrastructure for mollusc aquaculture health management is well characterized, its foundations are not without flaws. Use of notifiable pathogen lists can leave blind spots with regard to detection of unlisted and emerging pathogens. Increased reliance on molecular tools has come without similar attention to diagnostic validation, raising questions about assay performance, and has been accompanied by a reduced emphasis on microscopic diagnostic expertise that could weaken pathogen detection capabilities. Persistent questions concerning pathogen biology and ecology promote regulatory paralysis that impedes trade and which could weaken biosecurity by driving commerce to surreptitious channels. Solutions that might be pursued to improve shellfish aquaculture health management include the establishment of more broad-based surveillance programmes, wider training and use of general methods like histopathology to ensure alertness to emerging diseases, an increased focus on assay assessment and validation as fundamental to assay development, investment in basic research, and application of risk analyses to improve regulation. A continual sharpening of diagnostic tools and approaches and deepening of scientific knowledge is necessary to manage diseases and promote sustainable molluscan shellfish industries.
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Affiliation(s)
- Ryan B Carnegie
- Department of Aquatic Health Sciences, Virginia Institute of Marine Science, College of William & Mary, PO Box 1346, Gloucester Point, VA 23062, USA
| | - Isabelle Arzul
- Ifremer, SG2M-LGPMM, Laboratoire de Génétique et Pathologie des Mollusques Marins, Avenue de Mus de Loup, La Tremblade 17390, France
| | - David Bushek
- Haskin Shellfish Research Laboratory, Rutgers University, 6959 Miller Avenue, Port Norris, NJ 08349, USA
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Ramilo A, Pintado J, Villalba A, Abollo E. Perkinsus olseni and P. chesapeaki detected in a survey of perkinsosis of various clam species in Galicia (NW Spain) using PCR–DGGE as a screening tool. J Invertebr Pathol 2016; 133:50-8. [DOI: 10.1016/j.jip.2015.11.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 09/22/2015] [Accepted: 11/24/2015] [Indexed: 12/22/2022]
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26
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Rapid concentration and sensitive detection of hookworm ova from wastewater matrices using a real-time PCR method. Exp Parasitol 2015; 159:5-12. [DOI: 10.1016/j.exppara.2015.08.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Revised: 07/31/2015] [Accepted: 08/16/2015] [Indexed: 11/20/2022]
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27
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Ruano F, Batista FM, Arcangeli G. Perkinsosis in the clams Ruditapes decussatus and R. philippinarum in the Northeastern Atlantic and Mediterranean Sea: A review. J Invertebr Pathol 2015; 131:58-67. [DOI: 10.1016/j.jip.2015.07.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 07/29/2015] [Accepted: 07/30/2015] [Indexed: 11/16/2022]
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Valenzuela-Castillo A, Sánchez-Paz A, Castro-Longoria R, López-Torres MA, Grijalva-Chon JM. Seasonal changes in gene expression and polymorphism of hsp70 in cultivated oysters (Crassostrea gigas) at extreme temperatures. MARINE ENVIRONMENTAL RESEARCH 2015; 110:25-32. [PMID: 26254584 DOI: 10.1016/j.marenvres.2015.07.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 07/30/2015] [Accepted: 07/30/2015] [Indexed: 06/04/2023]
Abstract
The HSP70 proteins are an important element of the response against thermal stress and infectious diseases, and they are highly conserved and ubiquitous. In some species, variations on the hsp70 encoding sequence resulted in intraspecific differential expression, which leads to variations on thermo-tolerance among individuals. This phenomenon has not been described in the Pacific oyster Crassostrea gigas, which is cultivated in Mexico under temperature conditions highly above the optimal for this species. The present study was aimed to identify associations between hsp70 genotypes and their expression levels in C. gigas. By analyzing a 603 bp fragment from the 3' end of the hsp70 gene, 21 different genotypes with 60 nucleotide polymorphic sites were detected, of which 34 sites were found in heterozygous condition. Although no correlation was found between genotype-expression-season, a minimum expression threshold that should be taken into account as an important feature for a future breeding program is proposed.
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Affiliation(s)
- Adán Valenzuela-Castillo
- Universidad de Sonora, Departamento de Investigaciones Científicas y Tecnológicas, Hermosillo, Sonora 83000, Mexico
| | - Arturo Sánchez-Paz
- Centro de Investigaciones Biológicas del Noroeste S.C. Laboratorio de Referencia, Análisis y Diagnóstico en Sanidad Acuícola, Hermosillo, Sonora 83106, Mexico
| | - Reina Castro-Longoria
- Universidad de Sonora, Departamento de Investigaciones Científicas y Tecnológicas, Hermosillo, Sonora 83000, Mexico
| | - Marco Antonio López-Torres
- Universidad de Sonora, Departamento de Investigaciones Científicas y Tecnológicas, Hermosillo, Sonora 83000, Mexico
| | - José Manuel Grijalva-Chon
- Universidad de Sonora, Departamento de Investigaciones Científicas y Tecnológicas, Hermosillo, Sonora 83000, Mexico.
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Huver JR, Koprivnikar J, Johnson PTJ, Whyard S. Development and application of an eDNA method to detect and quantify a pathogenic parasite in aquatic ecosystems. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2015; 25:991-1002. [PMID: 26380540 PMCID: PMC4570504 DOI: 10.1890/14-1530.1] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Approaches based on organismal DNA found in the environment (eDNA) have become increasingly utilized for ecological studies and biodiversity inventories as an alternative to traditional field survey methods. Such DNA-based techniques have largely been used to establish the presence of free-living organisms, but have much potential for detecting and quantifying infectious agents in the environment, which is necessary to evaluate disease risk. We developed an eDNA method to examine the distribution and abundance of the trematode Ribeiroia ondatrae, a pathogenic parasite known to cause malformations in North American amphibians. In addition to comparing this eDNA approach to classical host necropsy, we examined the detectability of R. ondatrae in water samples subject to different degradation conditions (time and temperature). Our test exhibited high specificity and sensitivity to R. ondatrae, capable of detecting as little as 14 fg (femtograms) of this parasite's DNA (1/2500th of a single infectious stage) from field water samples. Compared to our results from amphibian host necropsy, quantitative PCR was -90% concordant with respect to R. ondatrae detection from 15 field sites and was also a significant predictor of host infection abundance. DNA was still detectable in lab samples after 21 days at 25°C, indicating that our method is robust to field conditions. By comparing the advantages and disadvantages of eDNA vs. traditional survey methods for determining pathogen presence and abundance in the field, we found that the lower cost and effort associated with eDNA approaches provide many advantages. The development of alternative tools is critical for disease ecology, as wildlife management and conservation efforts require reliable establishment and monitoring of pathogens.
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Affiliation(s)
- J. R. Huver
- Department of Biological Sciences, University of Manitoba
| | | | - P. T. J. Johnson
- Department of Ecology and Evolutionary Biology, University of Colorado Boulder
| | - S. Whyard
- Department of Biological Sciences, University of Manitoba
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Breitburg DL, Hondorp D, Audemard C, Carnegie RB, Burrell RB, Trice M, Clark V. Landscape-level variation in disease susceptibility related to shallow-water hypoxia. PLoS One 2015; 10:e0116223. [PMID: 25671595 PMCID: PMC4324988 DOI: 10.1371/journal.pone.0116223] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 12/03/2014] [Indexed: 11/19/2022] Open
Abstract
Diel-cycling hypoxia is widespread in shallow portions of estuaries and lagoons, especially in systems with high nutrient loads resulting from human activities. Far less is known about the effects of this form of hypoxia than deeper-water seasonal or persistent low dissolved oxygen. We examined field patterns of diel-cycling hypoxia and used field and laboratory experiments to test its effects on acquisition and progression of Perkinsus marinus infections in the eastern oyster, Crassostrea virginica, as well as on oyster growth and filtration. P. marinus infections cause the disease known as Dermo, have been responsible for declines in oyster populations, and have limited success of oyster restoration efforts. The severity of diel-cycling hypoxia varied among shallow monitored sites in Chesapeake Bay, and average daily minimum dissolved oxygen was positively correlated with average daily minimum pH. In both field and laboratory experiments, diel-cycling hypoxia increased acquisition and progression of infections, with stronger results found for younger (1-year-old) than older (2-3-year-old) oysters, and more pronounced effects on both infections and growth found in the field than in the laboratory. Filtration by oysters was reduced during brief periods of exposure to severe hypoxia. This should have reduced exposure to waterborne P. marinus, and contributed to the negative relationship found between hypoxia frequency and oyster growth. Negative effects of hypoxia on the host immune response is, therefore, the likely mechanism leading to elevated infections in oysters exposed to hypoxia relative to control treatments. Because there is considerable spatial variation in the frequency and severity of hypoxia, diel-cycling hypoxia may contribute to landscape-level spatial variation in disease dynamics within and among estuarine systems.
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Affiliation(s)
- Denise L. Breitburg
- Smithsonian Environmental Research Center, PO Box 28, Edgewater, MD, 21037, United States of America
| | - Darryl Hondorp
- Smithsonian Environmental Research Center, PO Box 28, Edgewater, MD, 21037, United States of America
- USGS Great Lakes Science Center, 1451 Green Road, Ann Arbor, MI, 48105, United States of America
| | - Corinne Audemard
- Virginia Institute of Marine Science, College of William and Mary, PO Box 1346, Gloucester Point, VA, 23062, United States of America
| | - Ryan B. Carnegie
- Virginia Institute of Marine Science, College of William and Mary, PO Box 1346, Gloucester Point, VA, 23062, United States of America
| | - Rebecca B. Burrell
- Smithsonian Environmental Research Center, PO Box 28, Edgewater, MD, 21037, United States of America
| | - Mark Trice
- Maryland Department of Natural Resources, 580 Taylor Avenue, Annapolis, MD, 21401, United States of America
| | - Virginia Clark
- Smithsonian Environmental Research Center, PO Box 28, Edgewater, MD, 21037, United States of America
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31
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Sühnel S, Ivachuk CDS, Schaefer ALC, Pontinha VA, Martins ML, Figueras A, Meyer GR, Jones SRM, Stewart JC, Gurney-Smith HJ, Magalhães ARM, Bower SM. Detection of a parasitic amoeba (Order Dactylopodida) in the female gonads of oysters in Brazil. DISEASES OF AQUATIC ORGANISMS 2014; 109:241-250. [PMID: 24991850 DOI: 10.3354/dao02748] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The impacts of oocyte parasites on the reproductive success of molluscs are largely unknown. In this study, we evaluated the presence of gonad parasites in 6 species of marine bivalve molluscs native to southern Brazil. Cultured bivalves included the mangrove oyster Crassostrea gasar (sometimes called C. brasiliana), the brown mussel Perna perna, the lion's paw scallop Nodipecten nodosus and the wing pearl oyster Pteria hirundo. Another species of mangrove oyster, C. rhizophorae, and the carib pointed venus clam Anomalocardia brasiliana (syn. A. flexuosa) were collected from the wild. Molluscs were collected in winter 2009 and summer 2010 for histopathological and molecular evaluation. An unknown ovarian parasite (UOP) was observed in histopathological sections of female gonads of C. gasar and C. rhizophorae. The UOP possessed features suggestive of amoebae, including an irregular outer membrane, frothy cytoplasm, a nucleus with a prominent central nucleolus and a closely associated basophilic parasome. PCR analysis was negative for Marteilioides chungmuensis, Perkinsus spp. and Paramoeba perurans. However, real-time PCR successfully amplified DNA from oyster gonads when using universal Paramoeba spp. primers. Also, conventional PCR amplified DNA using primers specific for Perkinsela amoebae-like organisms (syn. Perkinsiella), which are considered as endosymbionts of Parameoba spp., previously thought to be the parasome. Our results suggest that this UOP is a species of amoeba belonging to 1 of the 2 families of the order Dactylopodida, possibly related to Paramoeba spp. This study represents the first report of this type of organism in oysters. We found that C. gasar and C. rhizophorae were the most susceptible molluscs to these UOPs.
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Affiliation(s)
- Simone Sühnel
- Nucleus for Aquatic Pathology Studies, Federal University of Santa Catarina (UFSC), Rodovia Admar Gonzaga, 1346, 88040-900, Florianópolis, Santa Catarina (SC), Brazil
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Kirk NL, Ritson-Williams R, Coffroth MA, Miller MW, Fogarty ND, Santos SR. Tracking transmission of apicomplexan symbionts in diverse Caribbean corals. PLoS One 2013; 8:e80618. [PMID: 24260438 PMCID: PMC3833926 DOI: 10.1371/journal.pone.0080618] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 10/04/2013] [Indexed: 11/22/2022] Open
Abstract
Symbionts in each generation are transmitted to new host individuals either vertically (parent to offspring), horizontally (from exogenous sources), or a combination of both. Scleractinian corals make an excellent study system for understanding patterns of symbiont transmission since they harbor diverse symbionts and possess distinct reproductive modes of either internal brooding or external broadcast spawning that generally correlate with vertical or horizontal transmission, respectively. Here, we focused on the under-recognized, but apparently widespread, coral-associated apicomplexans (Protista: Alveolata) to determine if symbiont transmission depends on host reproductive mode. Specifically, a PCR-based assay was utilized towards identifying whether planula larvae and reproductive adults from brooding and broadcast spawning scleractinian coral species in Florida and Belize harbored apicomplexan DNA. Nearly all (85.5%; n = 85/89) examined planulae of five brooding species (Porites astreoides, Agaricia tenuifolia, Agaricia agaricites, Favia fragum, Mycetophyllia ferox) and adults of P. astreoides were positive for apicomplexan DNA. In contrast, no (n = 0/10) apicomplexan DNA was detected from planulae of four broadcast spawning species (Acropora cervicornis, Acropora palmata, Pseudodiploria strigosa, and Orbicella faveolata) and rarely in gametes (8.9%; n = 5/56) of these species sampled from the same geographical range as the brooding species. In contrast, tissue samples from nearly all (92.0%; n = 81/88) adults of the broadcast spawning species A. cervicornis, A. palmata and O. faveolata harbored apicomplexan DNA, including colonies whose gametes and planulae tested negative for these symbionts. Taken together, these data suggest apicomplexans are transmitted vertically in these brooding scleractinian coral species while the broadcast spawning scleractinian species examined here acquire these symbionts horizontally. Notably, these transmission patterns are consistent with those of other scleractinian coral symbionts. While this study furthers knowledge regarding these symbionts, numerous questions remain to be addressed, particularly in regard to the specific interaction(s) between these apicomplexans and their hosts.
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Affiliation(s)
- Nathan L. Kirk
- Auburn University, Department of Biological Sciences and Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn, Alabama, United States of America
- * E-mail:
| | | | - Mary Alice Coffroth
- State University of New York at Buffalo, Department of Geology, Buffalo, New York, United States of America
| | - Margaret W. Miller
- National Oceanic and Atmospheric Administration, Southeast Fisheries Science Center, Miami, Florida, United States of America
| | - Nicole D. Fogarty
- Oceanographic Center, Nova Southeastern University, Dania Beach, Florida, United States of America
| | - Scott R. Santos
- Auburn University, Department of Biological Sciences and Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn, Alabama, United States of America
- Cellular & Molecular Biosciences Peak Program, Auburn University, Auburn, Alabama, United States of America
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Picón-Camacho SM, Thompson WP, Blaylock RB, Lotz JM. Development of a rapid assay to detect the dinoflagellate Amyloodinium ocellatum using loop-mediated isothermal amplification (LAMP). Vet Parasitol 2013; 196:265-71. [DOI: 10.1016/j.vetpar.2013.04.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 04/01/2013] [Accepted: 04/02/2013] [Indexed: 11/28/2022]
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34
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Feng C, Wang C, Lin X, Zhang Y, Lv J, Deng J, Yuan X, Mei L, Wu S. Development of a loop-mediated isothermal amplification method for detection of Perkinsus spp. in mollusks. DISEASES OF AQUATIC ORGANISMS 2013; 104:141-148. [PMID: 23709467 DOI: 10.3354/dao02591] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Perkinsus is a genus of unicellular protozoan parasite responsible for mass mortality of several commercially valuable mollusks. Surveillance and inspection of its epidemiology in the field calls for convenient and rapid detection methods. Here, a loop-mediated isothermal amplification (LAMP) assay was developed to detect the presence of Perkinsus spp. in mollusks. Specific LAMP primers were designed targeting the conserved internal transcribed spacer 2 (ITS-2) region of the rRNA gene of Perkinsus spp. Using ITS-2 recombinant plasmid as a template, we optimized the LAMP reaction system and conditions and then evaluated the analytical sensitivity and specificity of the assay. The LAMP assay was validated using clam samples collected from coastal areas in eastern China and oysters imported to China and compared with the traditional Ray's fluid thioglycollate culture method (RFTM). Our results showed that the LAMP detection method for Perkinsus was successful. The detection limit was 10 copies of plasmid DNA. Compared to the RFTM assay, the LAMP detection method was more sensitive (56 versus 52 positive out of 60 samples). P. olseni and P. marinus from infected hosts were successfully detected by this method. The LAMP method is rapid, sensitive, and specific for Perkinsus spp. detection, and could be used to screen for perkinsosis both on farms and at ports.
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Affiliation(s)
- Chunyan Feng
- Institute of Animal Quarantine, Chinese Academy of Inspection and Quarantine, Beijing 100029, PR China
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35
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Caron DA. Towards a Molecular Taxonomy for Protists: Benefits, Risks, and Applications in Plankton Ecology. J Eukaryot Microbiol 2013; 60:407-13. [DOI: 10.1111/jeu.12044] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 03/11/2013] [Indexed: 11/26/2022]
Affiliation(s)
- David A. Caron
- Department of Biological Sciences; University of Southern California; Los Angeles California
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36
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Pagenkopp Lohan KM, Small HJ, Shields JD, Place AR, Reece KS. Conservation in the first internal transcribed spacer (ITS1) region of Hematodinium perezi (genotype III) from Callinectes sapidus . DISEASES OF AQUATIC ORGANISMS 2013; 103:65-75. [PMID: 23482386 DOI: 10.3354/dao02559] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Hematodinium spp. infections have been reported from blue crabs Callinectes sapidus in high-salinity waters of the USA from New Jersey to Texas. Recently, H. perezi (genotype III) has been proposed as the parasite species and genotype infecting blue crabs from Virginia; however, it is unknown whether this same genotype is present in blue crabs from other locations. To address this question, we collected 317 blue crabs from Massachusetts, Virginia, Georgia, Florida, Louisiana, and Texas to test for the presence of H. perezi (III) using a specific PCR assay targeting the first internal transcribed spacer (ITS1) region of the ribosomal RNA gene complex. To examine the genetic variation within H. perezi (III), ITS1 region sequences from the parasite in blue crabs from multiple locations were compared to each other and to those of H. perezi (III) found in alternate hosts from Virginia. In total, 34 distinct ITS1 sequence variants of the parasite were identified from blue crabs alone, and 38 distinct variants were identified when alternate hosts were included. However, a single ITS1 sequence variant appeared in all geographic regions and hosts, and also in blue crabs sampled from a previous study. The high similarity among all the ITS1 region sequences examined (>98%) and the observation of a single variant found throughout a large geographic range, strongly suggests that a single species and genotype of Hematodinium, specifically H. perezi (III), infects blue crabs from Virginia to Texas and multiple alternate host species in Virginia.
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Affiliation(s)
- Katrina M Pagenkopp Lohan
- Virginia Institute of Marine Science, The College of William & Mary, Gloucester Point, Virginia 23062, USA
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37
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Norini MP, Secher C, Lollier M, Jézéquel K, Cornu JY, Lebeau T. Quantification of the 16S-23S rRNA internal transcribed spacers of Burkholderia xenovorans strain LB400 using real-time PCR in soil samples. Lett Appl Microbiol 2013; 56:366-72. [PMID: 23384335 DOI: 10.1111/lam.12057] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 01/31/2013] [Accepted: 01/31/2013] [Indexed: 11/30/2022]
Abstract
This study establishes a new real-time PCR assay (using SYBR Green™ detection) for the identification and the direct quantification of specific individual Burkholderia xenovorans strain LB400 from DNA samples of soil and sediment. Specific primers were designed to amplify a 190-bp fragment of the 16S-23S rRNA internal transcribed spacers (ITS) from LB400. The specificity of primers was evaluated using 21 strains. The detection limit of the real-time PCR was analysed on soil samples inoculated with LB400 and was of 6 copies (10(5) CFU g(-1) of dry sample). The 16S-23S rRNA ITS primers developed in this work for rapid quantification of LB400 were validated. The assay allowed the quantification of LB400 as pure strain and among the indigenous microbial community in samples of soil and sediment (105-day experiment).
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Affiliation(s)
- M-P Norini
- EDBS, LVBE EA3991, University of Haute Alsace, Colmar Cedex, France.
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A duplex quantitative real-time PCR assay for the detection of Haplosporidium and Perkinsus species in shellfish. Parasitol Res 2013; 112:1597-606. [PMID: 23371501 DOI: 10.1007/s00436-013-3315-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 01/20/2013] [Indexed: 10/27/2022]
Abstract
A duplex quantitative real-time polymerase chain reaction (dq-PCR) assay was optimized to simultaneously detect Haplosporidium spp. and Perkinsus spp. of shellfish in one reaction. Two sets of specific oligonucleotide primers for Haplosporidium spp. and Perkinsus spp., along with two hydrolysis probes specific for each parasite group, were used in the assay. The dq-PCR results were detected and analyzed using the Light Cycler 2.0 software system. The dq-PCR identified and differentiated the two protozoan parasite groups. The sensitivity of the dq-PCR assay was 200 template copies for both Haplosporidium spp. and Perkinsus spp. No DNA product was amplified when known DNA from Marteilia refringens, Toxoplasma gondii, Bonamia ostreae, Escherichia coli, Cymndinium spp., Mykrocytos mackini, Vibrio parahaemolyticus, and shellfish tissue were used as templates. A total of 840 oyster samples from commercial cultivated shellfish farms from two coastal areas in China were randomly collected and tested by dq-PCR. The detection rate of Haplosporidium spp. was 8.6% in the Qindao, Shandong coastal area, whereas Perkinsus spp. was 8.3% coastal oysters cultivated from shellfish farms of Beihai, Guangxi. The dqPCR results suggested that Haplosporidium spp. was prevalent in oysters from Qindao, Shandong, while Perkinsus spp. was prevalent in oysters from the coastal areas of Beihai, Guangxi. This dq-PCR could be used as a diagnostic tool to detect Haplosporidium spp. and Perkinsus spp. in cultivated shellfish.
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Wilbur AE, Ford SE, Gauthier JD, Gomez-Chiarri M. Quantitative PCR assay to determine prevalence and intensity of MSX (Haplosporidium nelsoni) in North Carolina and Rhode Island oysters Crassostrea virginica. DISEASES OF AQUATIC ORGANISMS 2012; 102:107-118. [PMID: 23269385 DOI: 10.3354/dao02540] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The continuing challenges to the management of both wild and cultured eastern oyster Crassostrea virginica populations resulting from protozoan parasites has stimulated interest in the development of molecular assays for their detection and quantification. For Haplosporidium nelsoni, the causative agent of multinucleated sphere unknown (MSX) disease, diagnostic evaluations depend extensively on traditional but laborious histological approaches and more recently on rapid and sensitive (but not quantitative) end-point polymerase chain reaction (PCR) assays. Here, we describe the development and application of a quantitative PCR (qPCR) assay for H. nelsoni using an Applied Biosystems TaqMan® assay designed with minor groove binder (MGB) probes. The assay was highly sensitive, detecting as few as 20 copies of cloned target DNA. Histologically evaluated parasite density was significantly correlated with the quantification cycle (Cq), regardless of whether quantification was categorical (r2 = 0.696, p < 0.0001) or quantitative (r2 = 0.797, p < 0.0001). Application in field studies conducted in North Carolina, USA (7 locations), revealed widespread occurrence of the parasite with moderate to high intensities noted in some locations. In Rhode Island, USA, application of the assay on oysters from 2 locations resulted in no positives.
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Affiliation(s)
- Ami E Wilbur
- Department of Biology and Marine Biology, Center for Marine Science, University of North Carolina Wilmington, Wilmington, North Carolina 28409, USA.
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40
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Early host-pathogen interactions in marine bivalves: evidence that the alveolate parasite Perkinsus marinus infects through the oyster mantle during rejection of pseudofeces. J Invertebr Pathol 2012; 113:26-34. [PMID: 23274079 DOI: 10.1016/j.jip.2012.12.011] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 12/17/2012] [Accepted: 12/18/2012] [Indexed: 11/21/2022]
Abstract
Parasites have developed myriad strategies to reach and infect their specific hosts. One of the most common mechanisms for non-vector transmitted parasites to reach the internal host environment is by ingestion during feeding. In this study, we investigated the mechanisms of oyster host colonization by the alveolate Perkinsus marinus and focused on how oysters process infective waterborne P. marinus cells during feeding in order to determine the portal(s) of entry of this parasite to its host. We also compared the infectivity of freely-suspended cells of P. marinus with that of cells incorporated into marine aggregates to link changes in particle processing by the feeding organs with infection success and route. Finally, we evaluated the effect of oyster secretions (mucus) covering the feeding organs on P. marinus physiology because these host factors are involved in the processing of waterborne particles. The ensemble of results shows a unique mechanism for infection by which the parasite is mostly acquired during the feeding process, but not via ingestion. Rather, infection commonly occurs during the rejection of material as pseudofeces before reaching the mouth. The pseudofeces discharge area, a specialized area of the mantle where unwanted particles are accumulated for rejection as pseudofeces, showed significantly higher parasite loads than other host tissues including other parts of the mantle. Aggregated P. marinus cells caused significantly higher disease prevalence and infection intensities when compared to freely-suspended parasite cells. Mucus covering the mantle caused a quick and significant increase in parasite replication rates suggesting rapid impact on P. marinus physiology. A new model for P. marinus acquisition in oysters is proposed.
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Thanh HD, Park HK, Kim W, Shin HS. Development of a 16S-23S rRNA intergenic spacer-based quantitative PCR assay for improved detection and enumeration of Lactococcus garvieae. FEMS Microbiol Lett 2012; 339:10-6. [PMID: 23106479 DOI: 10.1111/1574-6968.12038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 10/23/2012] [Accepted: 10/23/2012] [Indexed: 11/29/2022] Open
Abstract
Lactococcus garvieae is an important foodborne pathogen causing lactococcosis associated with hemorrhagic septicemia in fish worldwide. A real-time quantitative polymerase chain reaction (qPCR) protocol targeting the 16S-23S rRNA intergenic spacer (ITS) region was developed for the detection and enum-eration of L. garvieae. The specificity was evaluated using genomic DNAs extracted from 66 cocci strains. Fourteen L. garvieae strains tested were positive, whereas 52 other strains including Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. hordniae and Lactococcus lactis ssp. cremoris did not show a specific signal. The minimal limit of detection was 2.63 fg of purified genomic DNA, equivalent to 1 genome of L. garvieae. The optimized protocol was applied for the survey of L. garvieae in naturally contaminated fish samples. Our results suggest that the qPCR protocol using ITS is a sensitive and efficient tool for the rapid detection and enumeration of L. garvieae in fish and fish-containing foods.
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Affiliation(s)
- Hien Dang Thanh
- Department of Microbiology, Chung-Ang University College of Medicine, Seoul, Korea
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Mancera N, Douma LG, James S, Liu S, Van A, Boucias DG, Tartar A. Detection of Helicosporidium spp. in metagenomic DNA. J Invertebr Pathol 2012; 111:13-9. [PMID: 22609409 DOI: 10.1016/j.jip.2012.05.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Revised: 04/30/2012] [Accepted: 05/04/2012] [Indexed: 11/25/2022]
Abstract
Distinct isolates of the invertebrate pathogenic alga Helicosporidium sp., collected from different insect hosts and different geographic locations, were processed to sequence the 18S rDNA and β-tubulin genes. The sequences were analyzed to assess genetic variation within the genus Helicosporidium and to design Helicosporidium-specific 18S rDNA primers. The specificity of these primers was demonstrated by testing not only on the Helicosporidium sp. isolates, but also on two trebouxiophyte algae known to be close Helicosporidium relatives, Prototheca wickerhamii and Prototheca zopfii. The genus-specific primers were used to develop a culture-independent assay aimed at detecting the presence of Helicosporidium spp. in environmental waters. The assay was based on the PCR amplification of 18SrDNA gene fragments from metagenomic DNA preparations, and it resulted in the amplification of detectable products for all sampled sites. Phylogenetic analyses that included the environmental sequences demonstrated that all amplification products clustered in a strongly supported, monophyletic Helicosporidium clade, thereby validating the metagenomic approach and the taxonomic origin of the produced environmental sequences. In addition, the phylogenetic analyses established that Helicosporidium spp. isolated from coleopteran hosts are more closely related to each other than they are to the isolate collected from a dipteran host. Finally, the phylogenetic trees depicted intergeneric relationships that supported a Helicosporidium-Prototheca cluster but did not support a Helicosporidium-Coccomyxa grouping, suggesting that pathogenicity to invertebrates evolved at least twice independently within the trebouxiophyte green algae.
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Affiliation(s)
- Norberto Mancera
- Division of Math, Science and Technology, Nova Southeastern University, Fort Lauderdale, FL, USA
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Seo JS, Jeon EJ, Kim MS, Woo SH, Kim JD, Jung SH, Park MA, Jee BY, Kim JW, Kim YC, Lee EH. Molecular identification and real-time quantitative PCR (qPCR) for rapid detection of Thelohanellus kitauei, a Myxozoan parasite causing intestinal giant cystic disease in the Israel carp. THE KOREAN JOURNAL OF PARASITOLOGY 2012; 50:103-11. [PMID: 22711920 PMCID: PMC3375447 DOI: 10.3347/kjp.2012.50.2.103] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Revised: 01/08/2012] [Accepted: 01/23/2012] [Indexed: 11/23/2022]
Abstract
Intestinal giant-cystic disease (IGCD) of the Israel carp (Cyprinus carpio nudus) has been recognized as one of the most serious diseases afflicting inland farmed fish in the Republic of Korea, and Thelohanellus kitauei has been identified as the causative agent of the disease. Until now, studies concerning IGCD caused by T. kitauei in the Israel carp have been limited to morphological and histopathological examinations. However, these types of diagnostic examinations are relatively time-consuming, and the infection frequently cannot be detected in its early stages. In this study, we cloned the full-length 18S rRNA gene of T. kitauei isolated from diseased Israel carps, and carried out molecular identification by comparing the sequence with those of other myxosporeans. Moreover, conventional PCR and real-time quantitative PCR (qPCR) using oligonucleotide primers for the amplification of 18S rRNA gene fragment were established for further use as methods for rapid diagnosis of IGCD. Our results demonstrated that both the conventional PCR and real-time quantitative PCR systems applied herein are effective for rapid detection of T. kitauei spores in fish tissues and environmental water.
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Affiliation(s)
- Jung Soo Seo
- Pathology Division, National Fisheries Research and Development Institute, Busan 619-705, Korea
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Pagenkopp Lohan KM, Reece KS, Miller TL, Wheeler KN, Small HJ, Shields JD. The Role of Alternate Hosts in the Ecology and Life History of Hematodinium sp., a Parasitic Dinoflagellate of the Blue Crab (Callinectes sapidus). J Parasitol 2012; 98:73-84. [DOI: 10.1645/ge-2854.1] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Hyman OJ, Collins JP. Evaluation of a filtration-based method for detecting Batrachochytrium dendrobatidis in natural bodies of water. DISEASES OF AQUATIC ORGANISMS 2012; 97:185-195. [PMID: 22422089 DOI: 10.3354/dao02423] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Infectious diseases are emerging as a significant threat to wildlife. The resulting increased effort to monitor wildlife diseases is driving the development of innovative pathogen monitoring techniques, including many polymerase chain reaction (PCR)-based diagnostics. Despite the utility of these PCR-based techniques, there is still much to be learned about their ability to accurately detect target pathogens in nature. We assessed the diagnostic sensitivity of a PCR-based water filtration technique to detect the directly transmitted aquatic fungal pathogen Batrachochytrium dendrobatidis (Bd) by comparing the results of 4 repeated filter sampling events from 20 ponds to those of skin swabs from ca. 60 boreal chorus frogs Pseudacris maculata from each pond. Filters failed to detect Bd in 31 to 77% of the swab-positive ponds, depending on the time of sampling. However, after 3 repeated sampling events, filtration of small volumes of water (ca. 600 ml) correctly identified 94% of the ponds that tested Bd positive with swabbing, with the highest rates of detection occurring after breeding but before larvae reached metamorphosis. Our results are a case study demonstrating the importance of timing and resampling for the detection of an aquatic microbial pathogen, Bd, from water. This will be a useful technique for monitoring Bd, but additional data are needed to test the degree to which our findings are species or population specific. Future studies need to examine the sensitivity of this technique in other habitats and species that host Bd. These studies will aid in the development of cost-effective monitoring regimes for Bd and potentially other aquatic pathogens.
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Affiliation(s)
- Oliver J Hyman
- Arizona State University, School of Life Sciences, 427 E. Tyler Mall, LSC 410, Tempe, Arizona 85287, USA.
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Gajamange D, Yoon JM, Park KI. Development of a real-time PCR method for detection and quantification of the parasitic protozoan Perkinsus olseni. ACTA ACUST UNITED AC 2011. [DOI: 10.9710/kjm.2011.27.4.387] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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47
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Small HJ, Pagenkopp KM. Reservoirs and alternate hosts for pathogens of commercially important crustaceans: a review. J Invertebr Pathol 2011; 106:153-64. [PMID: 21215362 DOI: 10.1016/j.jip.2010.09.016] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
There is a considerable body of literature describing the causative agents of many diseases of crustaceans. Given that many of these crustaceans support commercially important fisheries, it is somewhat surprising that comparatively little information is available regarding the natural transmission pathways and reservoirs of many of the disease-causing agents. In this paper we review what is known about reservoirs and alternate hosts for several important diseases of commercially important crustaceans and provide recommendations on future areas of research.
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Affiliation(s)
- Hamish J Small
- Virginia Institute of Marine Science (VIMS), College of William & Mary, P.O. Box 1346, Gloucester Point, VA 23062, USA.
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Schriewer A, Wehlmann A, Wuertz S. Improving qPCR efficiency in environmental samples by selective removal of humic acids with DAX-8. J Microbiol Methods 2011; 85:16-21. [DOI: 10.1016/j.mimet.2010.12.027] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2010] [Revised: 12/20/2010] [Accepted: 12/22/2010] [Indexed: 11/15/2022]
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Abbott CL, Gilmore SR, Lowe G, Meyer G, Bower S. Sequence homogeneity of internal transcribed spacer rDNA in Mikrocytos mackini and detection of Mikrocytos sp. in a new location. DISEASES OF AQUATIC ORGANISMS 2011; 93:243-250. [PMID: 21516977 DOI: 10.3354/dao02301] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Mikrocytos mackini is a microcell parasite of Pacific oysters only known to occur on the Pacific coast of North America. It is the only described species in the genus, although a genetically divergent Mikrocytos sp. organism has been reported once in both the Atlantic Ocean and China. We developed methods for sequencing the internal transcribed spacer (ITS) of rDNA for the purpose of characterizing extant diversity within M. mackini throughout its known geographic range, and surveying for other evidence of Mikrocytos sp. organisms. Our specific aims were to examine relatedness of M. mackini among sites to make inferences about its recent evolutionary history, and to provide baseline data for future development of a species-specific molecular detection method. We found a total lack of genetic variation within M. mackini across the complete ITS1-5.8S-ITS2 array in over 70 samples collected throughout its range. We hypothesize that this could be a result of a founder effect if the parasite had been introduced into its known range alongside its host, which was imported from Asia beginning around 1914 to about 1961. We detected a single divergent sequence at a short stretch of 18S that was identical to the Mikrocytos sp. detected elsewhere, which adds to the recent and growing body of evidence that Mikrocytos is much more broadly distributed than the limited range of M. mackini suggests. A 1903 bp section of rDNA from Mikrocytos sp. was generated that contained regions of high divergence from M. mackini (in ITS1 and ITS2) that could be exploited for molecular diagnostics.
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Affiliation(s)
- Cathryn L Abbott
- Pacific Biological Station, Department of Fisheries and Oceans, 3190 Hammond Bay Road, Nanaimo, British Columbia V9T 6N7, Canada.
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Development of a Real-Time PCR assay for quantitative assessment of uncultured freshwater zoosporic fungi. J Microbiol Methods 2010; 81:69-76. [PMID: 20153382 DOI: 10.1016/j.mimet.2010.02.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Revised: 02/03/2010] [Accepted: 02/06/2010] [Indexed: 11/22/2022]
Abstract
Recently, molecular environmental surveys of the eukaryotic microbial community in lakes have revealed a high diversity of sequences belonging to uncultured zoosporic fungi. Although they are known as saprobes and algal parasites in freshwater systems, zoosporic fungi have been neglected in microbial food web studies. Recently, it has been suggested that zoosporic fungi, via the consumption of their zoospores by zooplankters, could transfer energy from large inedible algae and particulate organic material to higher trophic levels. However, because of their small size and their lack of distinctive morphological features, traditional microscopy does not allow the detection of fungal zoospores in the field. Hence, quantitative data on fungal zoospores in natural environments is missing. We have developed a quantitative PCR (qPCR) assay for the quantification of fungal zoospores in lakes. Specific primers were designed and qPCR conditions were optimized using a range of target and non-target plasmids obtained from previous freshwater environmental 18S rDNA surveys. When optimal DNA extraction protocol and qPCR conditions were applied, the qPCR assay developed in this study demonstrated high specificity and sensitivity, with as low as 100 18S rDNA copies per reaction detected. Although the present work focuses on the design and optimization of a new qPCR assay, its application to natural samples indicated that qPCR offers a promising tool for quantitative assessment of fungal zoospores in natural environments. We conclude that this will contribute to a better understanding of the ecological significance of zoosporic fungi in microbial food webs of pelagic ecosystems.
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