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McGrath C. Highlight: Virtual Issue on Host–Pathogen Interactions and Antimicrobial Drug Resistance. Genome Biol Evol 2022. [PMCID: PMC9729932 DOI: 10.1093/gbe/evac165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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Bartholomew JL, Alexander JD, Hallett SL, Alama-Bermejo G, Atkinson SD. Ceratonova shasta: a cnidarian parasite of annelids and salmonids. Parasitology 2022; 149:1862-1875. [PMID: 36081219 PMCID: PMC11010528 DOI: 10.1017/s0031182022001275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 08/16/2022] [Accepted: 08/20/2022] [Indexed: 12/29/2022]
Abstract
The myxozoan Ceratonova shasta was described from hatchery rainbow trout over 70 years ago. The parasite continues to cause severe disease in salmon and trout, and is recognized as a barrier to salmon recovery in some rivers. This review incorporates changes in our knowledge of the parasite's life cycle, taxonomy and biology and examines how this information has expanded our understanding of the interactions between C. shasta and its salmonid and annelid hosts, and how overarching environmental factors affect this host–parasite system. Development of molecular diagnostic techniques has allowed discrimination of differences in parasite genotypes, which have differing host affinities, and enabled the measurement of the spatio-temporal abundance of these different genotypes. Establishment of the C. shasta life cycle in the laboratory has enabled studies on host–parasite interactions and the availability of transcriptomic data has informed our understanding of parasite virulence factors and host defences. Together, these advances have informed the development of models and management actions to mitigate disease.
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Affiliation(s)
- Jerri L. Bartholomew
- Department of Microbiology, Oregon State University, Nash Hall 226, Corvallis, Oregon 97331, USA
| | - Julie D. Alexander
- Department of Microbiology, Oregon State University, Nash Hall 226, Corvallis, Oregon 97331, USA
| | - Sascha L. Hallett
- Department of Microbiology, Oregon State University, Nash Hall 226, Corvallis, Oregon 97331, USA
| | - Gema Alama-Bermejo
- Institute of Parasitology, Biology Center of the Czech Academy of Sciences, Branisovska 31, 37005 Ceske Budejovice, Czech Republic
- Division of Fish Health, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Austria
| | - Stephen D. Atkinson
- Department of Microbiology, Oregon State University, Nash Hall 226, Corvallis, Oregon 97331, USA
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Kumar G, Sudhagar A, Shivam S, Nilsen F, Bartholomew JL, El-Matbouli M. Identification of in vivo induced antigens of the malacosporean parasite Tetracapsuloides bryosalmonae (Cnidaria) using in vivo induced antigen technology. Front Cell Infect Microbiol 2022; 12:1032347. [DOI: 10.3389/fcimb.2022.1032347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 09/30/2022] [Indexed: 11/13/2022] Open
Abstract
Tetracapsuloides bryosalmonae is a malacosporean endoparasite that causes proliferative kidney disease (PKD) in wild and farmed salmonids in Europe and North America. The life cycle of T. bryosalmonae completes between invertebrate bryozoan and vertebrate fish hosts. Inside the fish, virulence factors of T. bryosalmonae are induced during infection or interactions with host cells. T. bryosalmonae genes expressed in vivo are likely to be important in fish pathogenesis. Herein, we identify in vivo induced antigens of T. bryosalmonae during infection in brown trout (Salmo trutta) using in vivo induced antigen technology (IVIAT). Brown trout were exposed to the spores of T. bryosalmonae and were sampled at different time points. The pooled sera were first pre-adsorbed with antigens to remove false positive results. Subsequently, adsorbed sera were used to screen a T. bryosalmonae cDNA phage expression library. Immunoscreening analysis revealed 136 immunogenic T. bryosalmonae proteins induced in brown trout during parasite development. They are involved in signal transduction, transport, metabolism, ion-protein binding, protein folding, and also include hypothetical proteins, of so far unknown functions. The identified in vivo induced antigens will be useful in the understanding of T. bryosalmonae pathogenesis during infection in susceptible hosts. Some of the antigens found may have significant implications for the discovery of candidate molecules for the development of potential therapies and preventive measures against T. bryosalmonae in salmonids.
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Alama-Bermejo G, Bartošová-Sojková P, Atkinson SD, Holzer AS, Bartholomew JL. Proteases as Therapeutic Targets Against the Parasitic Cnidarian Ceratonova shasta: Characterization of Molecules Key to Parasite Virulence In Salmonid Hosts. Front Cell Infect Microbiol 2022; 11:804864. [PMID: 35071050 PMCID: PMC8777295 DOI: 10.3389/fcimb.2021.804864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 11/24/2021] [Indexed: 11/13/2022] Open
Abstract
Proteases and their inhibitors play critical roles in host-parasite interactions and in the outcomes of infections. Ceratonova shasta is a myxozoan pathogen that causes enteronecrosis in economically important salmonids from the Pacific Northwest of North America. This cnidarian parasite has host-specific genotypes with varying virulence, making it a powerful system to decipher virulence mechanisms in myxozoans. Using C. shasta genome and transcriptome, we identified four proteases of different catalytic types: cathepsin D (aspartic), cathepsin L and Z-like (cysteine) and aminopeptidase-N (metallo); and a stefin (cysteine protease inhibitor), which implied involvement in virulence and hence represent target molecules for the development of therapeutic strategies. We characterized, annotated and modelled their 3D protein structure using bioinformatics and computational tools. We quantified their expression in C. shasta genotype 0 (low virulence, no mortality) and IIR (high virulence and mortality) in rainbow trout Oncorhynchus mykiss, to demonstrate that there are major differences between the genotypes during infection and parasite development. High proliferation of genotype IIR was associated with high expression of the cathepsin D and the stefin, likely correlated with high nutrient demands and to regulate cell metabolism, with upregulation preceding massive proliferation and systemic dispersion. In contrast, upregulation of the cathepsin L and Z-like cysteine proteases may have roles in host immune evasion in genotype 0 infections, which are associated with low proliferation, low inflammation and non-destructive development. In contrast to the other proteases, C. shasta aminopeptidase-N appears to have a prominent role in nematocyst formation in both genotypes, but only during sporogenesis. Homology searches of C. shasta proteases against other myxozoan transcriptomes revealed a high abundance of cathepsin L and aminopeptidase homologs suggesting common gene requirements across species. Our study identified molecules of potential therapeutic significance for aquaculture and serves as a baseline for future research aimed at functional characterisation of these targets.
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Affiliation(s)
- Gema Alama-Bermejo
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czechia.,Department of Microbiology, Oregon State University, Corvallis, OR, United States
| | - Pavla Bartošová-Sojková
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czechia
| | - Stephen D Atkinson
- Department of Microbiology, Oregon State University, Corvallis, OR, United States
| | - Astrid S Holzer
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czechia
| | - Jerri L Bartholomew
- Department of Microbiology, Oregon State University, Corvallis, OR, United States
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Method for Isolation of Myxozoan Proliferative Stages from Fish at High Yield and Purity: An Essential Prerequisite for In Vitro, In Vivo and Genomics-Based Research Developments. Cells 2022; 11:cells11030377. [PMID: 35159187 PMCID: PMC8833907 DOI: 10.3390/cells11030377] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 01/11/2022] [Accepted: 01/17/2022] [Indexed: 12/21/2022] Open
Abstract
Myxozoans are a diverse group of microscopic cnidarian parasites and some representatives are associated with important diseases in fish, in both marine and freshwater aquaculture systems. Research on myxozoans has been largely hampered by the inability to isolate myxozoan parasites from their host tissues. In this study, we developed and optimized a method to isolate the myxozoan proliferative stages of different size and cellularity from fish blood, using DEAE-cellulose ion exchange chromatography. We optimized several parameters and obtained 99–100% parasite purity, as well as high survival and infectivity. Using polyclonal pan-carp blood cell-specific antibodies, we further developed a rapid cytometric assay for quantification of the proliferative stages, not only in highly concentrated DEAE-C isolates but also in dilute conditions in full blood. Early developmental stages of myxozoans are key to parasite proliferation, establishment, and pathology in their hosts. The isolation of these stages not only opens new possibilities for in vivo and in vitro studies, but also for obtaining purified DNA and protein extracts for downstream analyses. Hence, we provide a long-desired tool that will advance the functional research into the mechanisms of host exploitation and immune stimulation/evasion in this group, which could contribute greatly to the development of therapeutic strategies against myxozoans.
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Americus B, Hams N, Klompen AML, Alama-Bermejo G, Lotan T, Bartholomew JL, Atkinson SD. The cnidarian parasite Ceratonova shasta utilizes inherited and recruited venom-like compounds during infection. PeerJ 2022; 9:e12606. [PMID: 35003924 PMCID: PMC8684318 DOI: 10.7717/peerj.12606] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 11/16/2021] [Indexed: 12/12/2022] Open
Abstract
Background Cnidarians are the most ancient venomous organisms. They store a cocktail of venom proteins inside unique stinging organelles called nematocysts. When a cnidarian encounters chemical and physical cues from a potential threat or prey animal, the nematocyst is triggered and fires a harpoon-like tubule to penetrate and inject venom into the prey. Nematocysts are present in all Cnidaria, including the morphologically simple Myxozoa, which are a speciose group of microscopic, spore-forming, obligate parasites of fish and invertebrates. Rather than predation or defense, myxozoans use nematocysts for adhesion to hosts, but the involvement of venom in this process is poorly understood. Recent work shows some myxozoans have a reduced repertoire of venom-like compounds (VLCs) relative to free-living cnidarians, however the function of these proteins is not known. Methods We searched for VLCs in the nematocyst proteome and a time-series infection transcriptome of Ceratonova shasta, a myxozoan parasite of salmonid fish. We used four parallel approaches to detect VLCs: BLAST and HMMER searches to preexisting cnidarian venom datasets, the machine learning tool ToxClassifier, and structural modeling of nematocyst proteomes. Sequences that scored positive by at least three methods were considered VLCs. We then mapped their time-series expressions in the fish host and analyzed their phylogenetic relatedness to sequences from other venomous animals. Results We identified eight VLCs, all of which have closely related sequences in other myxozoan datasets, suggesting a conserved venom profile across Myxozoa, and an overall reduction in venom diversity relative to free-living cnidarians. Expression of the VLCs over the 3-week fish infection varied considerably: three sequences were most expressed at one day post-exposure in the fish’s gills; whereas expression of the other five VLCs peaked at 21 days post-exposure in the intestines, coinciding with the formation of mature parasite spores with nematocysts. Expression of VLC genes early in infection, prior to the development of nematocysts, suggests venoms in C. shasta have been repurposed to facilitate parasite invasion and proliferation within the host. Molecular phylogenetics suggested some VLCs were inherited from a cnidarian ancestor, whereas others were more closely related to sequences from venomous non-Cnidarian organisms and thus may have gained qualities of venom components via convergent evolution. The presence of VLCs and their differential expression during parasite infection enrich the concept of what functions a “venom” can have and represent targets for designing therapeutics against myxozoan infections.
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Affiliation(s)
- Benjamin Americus
- Department of Microbiology, Oregon State University, Corvallis, Oregon, United States of America
| | - Nicole Hams
- Columbia River Fish and Wildlife Conservation Office, U.S. Fish and Wildlife Service, Vancouver, Washington, United States of America
| | - Anna M L Klompen
- Department of Ecology and Evolutionary Biology, The University of Kansas, Lawrence, Kansas, United States of America
| | - Gema Alama-Bermejo
- Department of Microbiology, Oregon State University, Corvallis, Oregon, United States of America.,Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Tamar Lotan
- Marine Biology Department, The Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel
| | - Jerri L Bartholomew
- Department of Microbiology, Oregon State University, Corvallis, Oregon, United States of America
| | - Stephen D Atkinson
- Department of Microbiology, Oregon State University, Corvallis, Oregon, United States of America
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Holzer AS, Piazzon MC, Barrett D, Bartholomew JL, Sitjà-Bobadilla A. To React or Not to React: The Dilemma of Fish Immune Systems Facing Myxozoan Infections. Front Immunol 2021; 12:734238. [PMID: 34603313 PMCID: PMC8481699 DOI: 10.3389/fimmu.2021.734238] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 09/01/2021] [Indexed: 11/13/2022] Open
Abstract
Myxozoans are microscopic, metazoan, obligate parasites, belonging to the phylum Cnidaria. In contrast to the free-living lifestyle of most members of this taxon, myxozoans have complex life cycles alternating between vertebrate and invertebrate hosts. Vertebrate hosts are primarily fish, although they are also reported from amphibians, reptiles, trematodes, mollusks, birds and mammals. Invertebrate hosts include annelids and bryozoans. Most myxozoans are not overtly pathogenic to fish hosts, but some are responsible for severe economic losses in fisheries and aquaculture. In both scenarios, the interaction between the parasite and the host immune system is key to explain such different outcomes of this relationship. Innate immune responses contribute to the resistance of certain fish strains and species, and the absence or low levels of some innate and regulatory factors explain the high pathogenicity of some infections. In many cases, immune evasion explains the absence of a host response and allows the parasite to proliferate covertly during the first stages of the infection. In some infections, the lack of an appropriate regulatory response results in an excessive inflammatory response, causing immunopathological consequences that are worse than inflicted by the parasite itself. This review will update the available information about the immune responses against Myxozoa, with special focus on T and B lymphocyte and immunoglobulin responses, how these immune effectors are modulated by different biotic and abiotic factors, and on the mechanisms of immune evasion targeting specific immune effectors. The current and future design of control strategies for myxozoan diseases is based on understanding this myxozoan-fish interaction, and immune-based strategies such as improvement of innate and specific factors through diets and additives, host genetic selection, passive immunization and vaccination, are starting to be considered.
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Affiliation(s)
- Astrid S Holzer
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, České Budějovice, Czechia
| | - M Carla Piazzon
- Fish Pathology Group, Institute of Aquaculture Torre de la Sal - Consejo Superior de Investigaciones Científicas (IATS-CSIC), Castellón, Spain
| | - Damien Barrett
- Department of Microbiology, Oregon State University, Corvallis, OR, United States
| | - Jerri L Bartholomew
- Department of Microbiology, Oregon State University, Corvallis, OR, United States
| | - Ariadna Sitjà-Bobadilla
- Fish Pathology Group, Institute of Aquaculture Torre de la Sal - Consejo Superior de Investigaciones Científicas (IATS-CSIC), Castellón, Spain
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Eszterbauer E, Szegő D, Ursu K, Sipos D, Gellért Á. Serine protease inhibitors of the whirling disease parasite Myxobolus cerebralis (Cnidaria, Myxozoa): Expression profiling and functional predictions. PLoS One 2021; 16:e0249266. [PMID: 33780500 PMCID: PMC8007001 DOI: 10.1371/journal.pone.0249266] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 03/15/2021] [Indexed: 11/19/2022] Open
Abstract
Here, we studied the expression pattern and putative function of four, previously identified serine protease inhibitors (serpins) of Myxobolus cerebralis, a pathogenic myxozoan species (Cnidaria: Myxozoa) causing whirling disease of salmonid fishes. The relative expression profiles of serpins were determined at different developmental stages both in fish and in annelid hosts using serpin-specific qPCR assays. The expression of serpin Mc-S1 was similar throughout the life cycle, whereas a significant decrease was detected in the relative expression of Mc-S3 and Mc-S5 during the development in fish, and then in the sporogonic stage in the worm host. A decreasing tendency could also be observed in the expression of Mc-S4 in fish, which was, however, upregulated in the worm host. For the first time, we predicted the function of M. cerebralis serpins by the use of several bioinformatics-based applications. Mc-S1 is putatively a chymotrypsin-like inhibitor that locates extracellularly and is capable of heparin binding. The other three serpins are caspase-like inhibitors, and they are probably involved in protease and cell degradation processes during the early stage of fish invasion.
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Affiliation(s)
- Edit Eszterbauer
- Institute for Veterinary Medical Research, Centre for Agricultural Research, Budapest, Hungary
| | - Dóra Szegő
- Institute for Veterinary Medical Research, Centre for Agricultural Research, Budapest, Hungary
| | - Krisztina Ursu
- Veterinary Diagnostic Directorate, National Food Chain Safety Office, Budapest, Hungary
| | - Dóra Sipos
- Institute for Veterinary Medical Research, Centre for Agricultural Research, Budapest, Hungary
| | - Ákos Gellért
- Institute for Veterinary Medical Research, Centre for Agricultural Research, Budapest, Hungary
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9
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Advances and Discoveries in Myxozoan Genomics. Trends Parasitol 2021; 37:552-568. [PMID: 33619004 DOI: 10.1016/j.pt.2021.01.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/20/2021] [Accepted: 01/23/2021] [Indexed: 12/21/2022]
Abstract
Myxozoans are highly diverse and globally distributed cnidarian endoparasites in freshwater and marine habitats. They have adopted a heteroxenous life cycle, including invertebrate and fish hosts, and have been associated with diseases in aquaculture and wild fish stocks. Despite their importance, genomic resources of myxozoans have proven difficult to obtain due to their miniaturized and derived genome character and close associations with fish tissues. The first 'omic' datasets have now become the main resource for a better understanding of host-parasite interactions, virulence, and diversity, but also the evolutionary history of myxozoans. In this review, we discuss recent genomic advances in the field and outline outstanding questions to be answered with continuous and improved efforts of generating myxozoan genomic data.
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Bartošová-Sojková P, Kyslík J, Alama-Bermejo G, Hartigan A, Atkinson SD, Bartholomew JL, Picard-Sánchez A, Palenzuela O, Faber MN, Holland JW, Holzer AS. Evolutionary Analysis of Cystatins of Early-Emerging Metazoans Reveals a Novel Subtype in Parasitic Cnidarians. BIOLOGY 2021; 10:110. [PMID: 33546310 PMCID: PMC7913475 DOI: 10.3390/biology10020110] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/26/2021] [Accepted: 01/31/2021] [Indexed: 01/04/2023]
Abstract
The evolutionary aspects of cystatins are greatly underexplored in early-emerging metazoans. Thus, we surveyed the gene organization, protein architecture, and phylogeny of cystatin homologues mined from 110 genomes and the transcriptomes of 58 basal metazoan species, encompassing free-living and parasite taxa of Porifera, Placozoa, Cnidaria (including Myxozoa), and Ctenophora. We found that the cystatin gene repertoire significantly differs among phyla, with stefins present in most of the investigated lineages but with type 2 cystatins missing in several basal metazoan groups. Similar to liver and intestinal flukes, myxozoan parasites possess atypical stefins with chimeric structure that combine motifs of classical stefins and type 2 cystatins. Other early metazoan taxa regardless of lifestyle have only the classical representation of cystatins and lack multi-domain ones. Our comprehensive phylogenetic analyses revealed that stefins and type 2 cystatins clustered into taxonomically defined clades with multiple independent paralogous groups, which probably arose due to gene duplications. The stefin clade split between the subclades of classical stefins and the atypical stefins of myxozoans and flukes. Atypical stefins represent key evolutionary innovations of the two parasite groups for which their origin might have been linked with ancestral gene chimerization, obligate parasitism, life cycle complexity, genome reduction, and host immunity.
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Affiliation(s)
- Pavla Bartošová-Sojková
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, 37005 České Budějovice, Czech Republic; (J.K.); (G.A.-B.); (A.P.-S.); (A.S.H.)
| | - Jiří Kyslík
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, 37005 České Budějovice, Czech Republic; (J.K.); (G.A.-B.); (A.P.-S.); (A.S.H.)
- Faculty of Science, University of South Bohemia, 37005 České Budějovice, Czech Republic
| | - Gema Alama-Bermejo
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, 37005 České Budějovice, Czech Republic; (J.K.); (G.A.-B.); (A.P.-S.); (A.S.H.)
| | - Ashlie Hartigan
- Department of Life Sciences, Natural History Museum, London SW7 5BD, UK;
| | - Stephen D. Atkinson
- Department of Microbiology, Oregon State University, Corvallis, OR 97331, USA; (S.D.A.); (J.L.B.)
| | - Jerri L. Bartholomew
- Department of Microbiology, Oregon State University, Corvallis, OR 97331, USA; (S.D.A.); (J.L.B.)
| | - Amparo Picard-Sánchez
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, 37005 České Budějovice, Czech Republic; (J.K.); (G.A.-B.); (A.P.-S.); (A.S.H.)
- Fish Pathology Group, Instituto de Acuicultura Torre de la Sal (IATS-CSIC), 12595 Castellón, Spain;
| | - Oswaldo Palenzuela
- Fish Pathology Group, Instituto de Acuicultura Torre de la Sal (IATS-CSIC), 12595 Castellón, Spain;
| | - Marc Nicolas Faber
- Scottish Fish Immunology Research Centre, Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 3UU, UK; (M.N.F.); (J.W.H.)
| | - Jason W. Holland
- Scottish Fish Immunology Research Centre, Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 3UU, UK; (M.N.F.); (J.W.H.)
| | - Astrid S. Holzer
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, 37005 České Budějovice, Czech Republic; (J.K.); (G.A.-B.); (A.P.-S.); (A.S.H.)
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Know your enemy - transcriptome of myxozoan Tetracapsuloides bryosalmonae reveals potential drug targets against proliferative kidney disease in salmonids. Parasitology 2021; 148:726-739. [PMID: 33478602 PMCID: PMC8056827 DOI: 10.1017/s003118202100010x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The myxozoan Tetracapsuloides bryosalmonae is a widely spread endoparasite that causes proliferative kidney disease (PKD) in salmonid fish. We developed an in silico pipeline to separate transcripts of T. bryosalmonae from the kidney tissue of its natural vertebrate host, brown trout (Salmo trutta). After stringent filtering, we constructed a partial transcriptome assembly T. bryosalmonae, comprising 3427 transcripts. Based on homology-restricted searches of the assembled parasite transcriptome and Atlantic salmon (Salmo salar) proteome, we identified four protein targets (Endoglycoceramidase, Legumain-like protease, Carbonic anhydrase 2, Pancreatic lipase-related protein 2) for the development of anti-parasitic drugs against T. bryosalmonae. Earlier work of these proteins on parasitic protists and helminths suggests that the identified anti-parasitic drug targets represent promising chemotherapeutic candidates also against T. bryosalmonae, and strengthen the view that the known inhibitors can be effective in evolutionarily distant organisms. In addition, we identified differentially expressed T. bryosalmonae genes between moderately and severely infected fish, indicating an increased abundance of T. bryosalmonae sporogonic stages in fish with low parasite load. In conclusion, this study paves the way for future genomic research in T. bryosalmonae and represents an important step towards the development of effective drugs against PKD.
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12
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Taggart-Murphy L, Alama-Bermejo G, Dolan B, Takizawa F, Bartholomew J. Differences in inflammatory responses of rainbow trout infected by two genotypes of the myxozoan parasite Ceratonova shasta. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 114:103829. [PMID: 32846161 PMCID: PMC7655565 DOI: 10.1016/j.dci.2020.103829] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 08/10/2020] [Accepted: 08/10/2020] [Indexed: 06/11/2023]
Abstract
Two genotypes of the intestinal parasite Ceratonova shasta infect Oncorhynchus mykiss: genotype 0 results in a chronic infection with low mortality while genotype IIR causes disease with high mortality. We determined parasite load and the relative expression of six immune factors (IgT, IgM, IL-6, IL-8, IL-10, IFNG) in fish infected with either genotype over 29 days post-exposure. In genotype IIR infections the host responded with upregulation of inflammatory and regulatory cytokines. In contrast, genotype 0 infection did not elicit an inflammatory response and expression of IFNG and IL-10 was lower. Antibody expression was upregulated in both infections but appeared to have limited efficacy in the virulent genotype IIR infections. Histologically, in genotype 0 infections the parasite migrated through the tissue layers causing inflammation but minimal damage to the mucosal epithelium, which contrasts with the severe pathology found in genotype IIR infections.
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Affiliation(s)
- Laura Taggart-Murphy
- Department of Microbiology, 226 Nash Hall, Oregon State University, Corvallis, OR, 97331, USA
| | - Gema Alama-Bermejo
- Department of Microbiology, 226 Nash Hall, Oregon State University, Corvallis, OR, 97331, USA; Institute of Parasitology, Biology Center of the Czech Academy of Sciences, České Budějovice, 37005, Czech Republic
| | - Brian Dolan
- Department of Biomedical Sciences, 106 Dryden Hall, Oregon State University, Corvallis, OR, 97331, USA
| | - Fumio Takizawa
- Faculty of Marine Science and Technology, Fukui Prefectural University, Obama, Fukui, Japan
| | - Jerri Bartholomew
- Department of Microbiology, 226 Nash Hall, Oregon State University, Corvallis, OR, 97331, USA.
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Genetic Diversity of Serine Protease Inhibitors in Myxozoan (Cnidaria, Myxozoa) Fish Parasites. Microorganisms 2020; 8:microorganisms8101502. [PMID: 33003479 PMCID: PMC7650755 DOI: 10.3390/microorganisms8101502] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 09/25/2020] [Accepted: 09/27/2020] [Indexed: 01/02/2023] Open
Abstract
We studied the genetic variability of serine protease inhibitors (serpins) of Myxozoa, microscopic endoparasites of fish. Myxozoans affect the health of both farmed and wild fish populations, causing diseases and mortalities. Despite their global impact, no effective protection exists against these parasites. Serpins were reported as important factors for host invasion and immune evasion, and as promising targets for the development of antiparasitic therapies. For the first time, we identified and aligned serpin sequences from high throughput sequencing datasets of ten myxozoan species, and analyzed 146 serpins from this parasite group together with those of other taxa phylogenetically, to explore their relationship and origins. High intra- and interspecific variability was detected among the examined serpins. The average sequence identity was 25–30% only. The conserved domains (i.e., motif and signature) showed taxon-level differences. Serpins clustered according to taxonomy rather than to serpin types, and myxozoan serpins seemed to be highly divergent from that of other taxa. None of them clustered with their closest relative free-living cnidarians. The genetic distinction of myxozoan serpins further strengthens the idea of an independent origin of Myxozoa, and may indicate novel protein functions potentially related to parasitism in this animal group.
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