| review of myxosporea of importance in salmonid fisheries and aquaculture in british columbia. | several myxosporean parasites are of importance in fisheries and aquaculture in british columbia. the pkx organism and ceratomyxa shasta noble, 1950 cause disease and mortality, kudoa thyrsites (gilchrist, 1924) and henneguya salminicola ward, 1919 are of importance because they infect somatic muscle, cause unsightly cysts and soft flesh, and thus reduce the market value of the fish. myxobolus arcticus pugachev et khokhlov, 1979, an apparently non-pathogenic species, along with h. salminicola, i ... | 1994 | 8050752 |
| sea trout, salmo trutta, a new host for the myxosporean kudoa thyrsites (gilchrist)? | | 1994 | 8085313 |
| infection of aulorhynchus flavidus (gill) (osteichthyes: gasterosteiformes) by kudoa thyrsites (gilchrist) (myxosporea: multivalvulida). | the myxosporean parasite kudoa thyrsites is reported from a new host, aulorhynchus flavidus, the tube-snout, collected near vancouver, british columbia, canada. prevalence reached 100% and intensity 1,535 pseudocysts per 2 cm length of fish. polymerase chain reaction primers specific for k. thyrsites amplified a fragment of the small subunit rdna and confirmed identification. these primers also allowed detection of k. thyrsites in young (< 4-mo-old) fish with no other apparent sign of infection. ... | 1997 | 9379282 |
| development of kudoa thyrsites (myxozoa: myxosporea) in netpen-reared atlantic salmon determined by light microscopy and a polymerase chain reaction test. | the intramuscular phase of development of kudoa thyrsites, the myxosporean associated with post-mortem myoliquefaction, or 'soft flesh syndrome', is described using histological preparations of the musculature of seawater netpen-reared atlantic salmon salmo salar. hatchery-reared atlantic salmon were naturally exposed to the infective stage while held in the experimental seawater netpens of the pacific biological station in nanaimo, british columbia, canada. in fish exposed during the summer of ... | 1999 | 10546048 |
| marine netpen farming leads to infections with some unusual parasites. | marine netpen farming of salmonid fishes is a rapidly growing industry in several countries. with this relatively recent industry, new or unusual infections by parasitic pathogens have been observed. this is due to different hosts being reared in new geographic areas, or by indigenous species being reared in a different environmental condition, i.e. the marine netpen. examples of the former include kudoa thyrsites (myxozoa) and hemobaphes disphaerocephalus (copepoda) infections in atlantic salmo ... | 2000 | 10719125 |
| recent advances in our knowledge of the myxozoa. | in the last few years two factors have helped to significantly advance our understanding of the myxozoa. first, the phenomenal increase in fin fish aquaculture in the 1990s has lead to the increased importance of these parasites; in turn this has lead to intensified research efforts, which have increased knowledge of the development, diagnosis. and pathogenesis of myxozoans. the hallmark discovery in the 1980s that the life cycle of myxobolus cerebralis requires development of an actinosporean s ... | 2001 | 11456316 |
| analysis of kudoa thyrsites (myxozoa: myxosporea) spore antigens using monoclonal antibodies. | a method employing percoll gradient centrifugation was developed to purify kudoa thyrsites spores from somatic muscle tissue of atlantic salmon salmo salar. highly purified spores were then used to immunize inbred balb/c mice for derivation of hybridomas secreting kudoa-specific monoclonal antibodies (mabs). analysis of mabs by immunofluorescence microscopy and flow cytometry showed that several were specific for antigens on the surface of k. thyrsites spores whereas other mabs reacted with pola ... | 2001 | 11463099 |
| the occurrence and mechanisms of innate immunity against parasites in fish. | parasitic infections in teleost fish are limited by constitutive innate defence mechanisms that render the host refractory or reduce the severity of infection. controlled challenge trials using naive animals provide indirect evidence of innate immunity as well as identifying the host range or specificity of a parasite, often when specific details of defence mechanism(s) are lacking. examples of parasites for which innate immunity may be inferred from cross-infectivity studies include gyrodactylu ... | 2001 | 11602199 |
| first report of three kudoa species from eastern australia: kudoa thyrsites from mahi mahi (coryphaena hippurus), kudoa amamiensis and kudoa minithyrsites n. sp. from sweeper (pempheris ypsilychnus). | fish species around the world are parasitized by myxozoans of the genus kudoa, several of which infect and cause damage of commercial importance. in particular, kudoa thyrsites and kudoa amamiensis infect certain cultured fish species causing damage to muscle tissue, making the fish unmarketable. kudoa thyrsites has a broad host and geographic range infecting over 35 different fish species worldwide, while k. amamiensis has only been reported from a few species in japanese waters. through morpho ... | 2003 | 12836879 |
| immunological detection of kudoa thyrsites spores in muscle tissues of farmed atlantic salmon, salmo salar l. | | 2003 | 12946013 |
| the relationship between flesh quality and numbers of kudoa thyrsites plasmodia and spores in farmed atlantic salmon, salmo salar l. | atlantic salmon, salmo salar l., were exposed to kudoa thyrsites (myxozoa, myxosporea)-containing sea water for 15 months, and then harvested and assessed for parasite burden and fillet quality. at harvest, parasites were enumerated in muscle samples from a variety of somatic and opercular sites, and mean counts were determined for each fish. after 6 days storage at 4 degrees c, fillet quality was determined by visual assessment and by analysis of muscle firmness using a texture analyzer. fillet ... | 2003 | 14513969 |
| [the parasite fauna of the chub mackerel (scombridae: scomber japonicus houttuyn, 1782) in the central-eastern atlantic (atlantic coast of the northern africa and the azores archipelago banks)]. | the parasite fauna of the chub mackerel scomber japonicus houtuym, 1782 was studied from the neritic areas of morocco, western sahara, mauritania and from the banks of the azores archipelago (the great meteor bank, the hyeres bank and the irving bank) in 1994-2001. twenty eight species of parasites of following group have been were found: coccidia (1 species), microsporidia (1), myxosporea (4), monogenea (4), cestoda (5), trematoda (5), acanthocephala (1) and nematoda (6). the differences betwee ... | 2004 | 15174392 |
| the effect of vaccination and sea water entry on immunocompetence and susceptibility to kudoa thyrsites in atlantic salmon (salmo salar l.). | the effect of intraperitoneal (ip) vaccination and sea water entry (swe) on the immunocompetence of cascade atlantic salmon was investigated. smolts were ip injected with aqua health's forte trade mark vaccine (listonella (vibrio) anguillarum, listonella ordalii, vibrio salmonicida and aeromonas salmonicida) at four times (42, 238, 433 and 630 degree days, dd) prior to swe and were examined for immunocompetence. immune response measurements included mitogen-driven proliferation of peripheral blo ... | 2004 | 15312664 |
| myxobolus cerebralis internal transcribed spacer 1 (its-1) sequences support recent spread of the parasite to north america and within europe. | molecular approaches for resolving relationships among the myxozoa have relied mainly on small subunit (ssu) ribosomal dna (rdna) sequence analysis. this region of the gene is generally used for higher phylogenetic studies, and the conservative nature of this gene may make it inadequate for intraspecific comparisons. previous intraspecific studies of myxobolus cerebralis based on molecular analyses reported that the sequence of ssu rdna and the internal transcribed spacer (its) were highly conse ... | 2004 | 15460854 |
| epitopes associated with mature spores not recognized on kudoa thyrsites from recently infected atlantic salmon smolts. | atlantic salmon salmo salar skeletal muscle was examined for kudoa thyrsites by polymerase chain reaction (pcr) and positive fish were further examined by in situ hybridization (ish) and immunohistochemistry (ihc). the infection was detected in 42% of salmon by pcr following a 60 d exposure to infective seawater at a temperature of 10 degrees c (= 600 degree-days, degreed). the parasite was detected by ish in skeletal and cardiac muscle but not in gill, kidney, spleen, liver, stomach, intestine, ... | 2005 | 15819443 |
| two multivalvulid myxozoans causing postmortem myoliquefaction: kudoa megacapsula n. sp. from red barracuda (sphyraena pinguis) and kudoa thyrsites from splendid alfonso (beryx splendens). | postmortem myoliquefaction associated with multivalvulid myxozoans was found in fillets of red barracuda (sphyraena pinguis) and splendid alfonso (beryx splendens), which were imported to japan from china and south africa, respectively. morphological examinations of the myxozoans from the somatic muscle of red barracuda revealed that spores (30.3-44.7 microm in maximum thickness) had 4 distinct winglike valves, in which 1 extremely large (12.7 x 5.8 microm), 2 small, and 1 vestigial polar capsul ... | 2005 | 16419760 |
| phylogeography of the cosmopolitan marine parasite kudoa thyrsites (myxozoa: myxosporea). | kudoa thyrsites (myxozoa: multivalvulida) is a cosmopolitan marine parasite of fishes associated with post-mortem tissue degradation. financial losses incurred as a result of these infections are of concern to commercial fisheries. there is conflicting evidence whether k. thyrsites represents a cryptic species complex. myxospore morphology is very similar for k. thyrsites across its range, but preliminary genetic analyses show some differences. kudoa thyrsites and the morphologically similar kud ... | 2006 | 16968454 |
| polymerase chain reaction assay for the detection of kudoa paniformis and kudoa thyrsites in pacific hake (merluccius productus). | myoliquefaction of pacific hake has been attributed to proteolytic action associated with parasitic infection. among the two infecting species of kudoa, kudoa paniformis and kudoa thyrsites, the former is reported to be more virulent for the "soft flesh" phenomenon in pacific hake. the objective of this research was to develop a sensitive and specific polymerase chain reaction (pcr) assay to detect infection of hake by k. paniformis. primers based on specific regions ( approximately 1562 bp) of ... | 2007 | 17419637 |
| development and validation of an rna- and dna-based quantitative pcr assay for determination of kudoa thyrsites infection levels in atlantic salmon salmo salar. | quantitative pcr (qpcr) methods targeting the 18s rdna gene (dna qpcr) and cathepsin l mrna (rna qpcr) from kudoa thyrsites (gilchrist) were developed and compared with histology for determination of k. thyrsites infection levels in atlantic salmon salmo salar l. both qpcr tests were specific, reproducible and sensitive down to 3 copies. dna qpcr was able to detect lower k. thyrsites infection levels than those detected by rna qpcr and histology. the higher sensitivity of the dna-based test comp ... | 2007 | 17629119 |
| identification, characterization and deduced amino acid sequence of the dominant protease from kudoa paniformis and k. thyrsites: a unique cytoplasmic cysteine protease. | kudoa paniformis and kudoa thyrsites (myxozoa: myxosporea) infections are associated with severe proteolysis of host muscle tissue post-mortem. the present study was undertaken to identify and characterize the protease responsible for myoliquefaction and determine mechanisms controlling protease function in vivo. n-terminal sequence analysis of partially purified protease from hake muscle infected with k. paniformis and k. thyrsites revealed a 23 amino acid sequence that aligned with cysteine pr ... | 2008 | 18187354 |
| occurrence of postmortem myoliquefactive kudoosis in atlantic mackerel, scomber scombrus l., from the north sea. | members of the myxosporean genus kudoa occur in various marine teleosts worldwide. several species are of concern to the fishery and aquaculture industries as they may produce unsightly cysts in the fish host's musculature or are associated with postmortem myoliquefaction of the fish muscle, commonly referred to as 'soft flesh'. this study describes the occurrence and effects on a host of a kudoa species in atlantic mackerel, scomber scombrus, from the northern north sea. generalized postmortem ... | 2008 | 18482379 |
| heart and skeletal muscle inflammation (hsmi) disease diagnosed on a british columbia salmon farm through a longitudinal farm study. | heart and skeletal muscle inflammation (hsmi) is an emerging disease of marine-farmed atlantic salmon (salmo salar), first recognized in 1999 in norway, and later also reported in scotland and chile. we undertook a longitudinal study involving health evaluation over an entire marine production cycle on one salmon farm in british columbia (canada). in previous production cycles at this farm site and others in the vicinity, cardiac lesions not linked to a specific infectious agent or disease were ... | 2017 | 28225783 |
| development of pcr method for detecting kudoa iwatai (myxozoa: multivalvulida) from rock bream oplegnathus fasciatus. | we developed a pcr assay targeting the 28s rdna of kudoa iwatai (multivalvulida: myxozoa) and investigated the prevalence of infection in rock bream oplegnathus fasciatus, which is commercially an important aquaculture species in korea, with this assay. detection limit of the pcr assay was 2.5 fg/μl with plasmid dna and 8.6 × 10(3) spores/ml with purified spores, respectively. this pcr assay did not amplify dna of other kudoa species (kudoa septempunctata, kudoa lateolabracis, kudoa thyrsites) t ... | 2017 | 28012028 |
| new host records of monacanthid fish for three kudoa spp. (k. septempunctata, k. thyrsites, and k. shiomitsui) prevalent in the olive flounder (paralichthys olivaceus), with the description of k. parathyrsites n. sp. from a black scraper (thamnaconus modestus). | kudoa septempunctata (myxosporean: multivalvulida) is known as a cause of foodborne disease associated with consumption of raw flesh of the olive flounder (paralichthys olivaceus). knowledge of its life cycle, particularly alternate annelid hosts and reservoirs or susceptible fish hosts in natural waters, may facilitate disease control in aquaculture farms. our recent survey of myxosporean infection in monacanthid fish in natural waters around japan revealed infection with three kudoid species p ... | 2016 | 27026502 |
| acquired protective immunity in atlantic salmon salmo salar against the myxozoan kudoa thyrsites involves induction of mhiiβ+ cd83+ antigen-presenting cells. | the histozoic myxozoan parasite kudoa thyrsites causes postmortem myoliquefaction and is responsible for economic losses to salmon aquaculture in the pacific northwest. despite its importance, little is known about the host-parasite relationship, including the host response to infection. the present work sought to characterize the immune response in atlantic salmon during infection, recovery, and reexposure to k. thyrsites after exposure to infective seawater, infected and uninfected smolts were ... | 2018 | 28993459 |
| long-term epidemiological survey of kudoa thyrsites (myxozoa) in atlantic salmon (salmo salar l.) from commercial aquaculture farms. | kudoa thyrsites (myxozoa) encysts within myocytes of a variety of fishes. while infected fish appear unharmed, parasite-derived enzymes degrade the flesh post-mortem. in regions of british columbia (bc), canada, up to 4-7% of fillets can be affected, thus having economic consequences and impacting the competitiveness of bc's farms. k. thyrsites was monitored in two farms having high (hp) or low (lp) historical infection prevalence. at each farm, 30 fish were sampled monthly for blood and muscle ... | 2016 | 26661293 |
| development of loop-mediated isothermal amplification method for detection of kudoa septempunctata (myxozoa: multivalvulida) in olive flounder (paralichthys olivaceus). | a loop-mediated isothermal amplification (lamp) assay was developed and validated for early, rapid, and sensitive detection of kudoa septempunctata, a myxosporean parasite found in olive flounder (paralichthys olivaceus). recently, several outbreaks associated with ingestion of raw olive flounder muscles harboring mature k. septempunctata spores have been reported, and it is becoming obvious that fresh k. septempunctata spores can cause problems in humans when ingested. thus, it is necessary to ... | 2014 | 24626774 |