Publications

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[new data on biology and ecology of ichthyophthirius multifiliis fouquet]. 195214926624
[immunity of fish to ichthyophthirius multifiliis fouquet infection]. 195313116925
[attempt of cultivation in vitro of ichthyophthirius multifiliis fouquet]. 19674866640
[on the structure of the macronucleus of the parasitic infusoria ichthyophthirius multifiliis]. 19674989011
[ultra-fine structure of the nuclear apparatus of ichthyophthirius multifiliis at the cystal stage in protomites]. 19684989386
[human pathogenicity of ichthyophthirius multifiliis]. 19694987193
[peculiar mode of division in ichthyophthirius multifiliis]. 19724199487
[acetomyosin-like filaments in the dividing macronucleus of the ciliated protozoon ichthyophthirius multifiliis (author's transl)]. 19734130186
sublethal copper stress and susceptibility of channel catfish to experimental infections with ichthyophthirius multifiliis. 19826809081
[changes in the electrolyte composition of the blood and muscles in carp infection with ichthyophthirius multifiliis (ciliata, ophryoglenidae)].a study of the electrolytic contents of blood serum, erythrocytes and muscles of carp infected with ichthyophthirius multifiliis was carried out. whatever the infection intensity, a characteristic increase in the cations k+ and na+ ratio in the plasma and muscles of infected fishes takes place. the above dependence, which is expressed in the intensification of active ions transport, is associated with mobilization of organism's protective functions.19846441141
[reproduction of ichthyophthirius multifiliis (ciliata, ophryoglenidae)].a case of reproduction of ichthyophthirius multifiliis in the superficial tissues of larvae and fry of amur wild carp is described. at a temperature of water from 28 to 29 degrees trophonts of ichthyophthirius encysted on fishes. inside cysts repeated cell division occurred but this process did not result in swarm spores formation. later on with the increase of temperature to 29.5--31.5 degrees cysts degenerated.19853937118
mobilization and activation of nonspecific cytotoxic cells (ncc) in the channel catfish (ictalurus punctatus) infected with ichthyophthirius multifiliis.channel catfish demonstrate a shift in the tissue distribution of nonspecific cytotoxic cells (ncc) when infected with the protozoan parasite, ichthyophthirius multifiliis. ncc, isolated from head kidney (hk) tissues (hemopoietic organ) or peripheral blood leukocytes, were assessed for cytotoxic activity against nc-37 (a transformed mammalian cell line). ncc activity from hk tissue of moribund i. multifiliis-infected fish was depressed compared to hk-ncc activity in uninfected or i. multifillis- ...19854064624
antiprotozoan activity of nonspecific cytotoxic cells (ncc) from the channel catfish (ictalurus punctatus).nonspecific cytotoxic cells (ncc) obtained from channel catfish (ictalurus punctatus) kill tetrahymena pyriformis, an opportunistic parasite in fish. based upon this fact, a new mechanism for nonspecific cellular anti-parasitic immunity in fish is proposed. optimum in vitro conditions for ncc killing of deciliated t. pyriformis were first obtained. lysis of t. pyriformis by ncc occurred by 10 hr of cocultivation of effector and target cells. during this time period, 50 to 60% cytotoxicity occurr ...19852578055
ascorbic acid induced immune-mediated decrease in mortality in ichthyophthirius multifiliis infected rainbow-trout (salmo gairdneri). 19862877556
acquired resistance of black mollies poecilia latipinna to infection by ichthyophthirius multifiliis.changes in the response of black mollies poecilia latipinna to infection with ichthyophthirius multifiliis subsequent to single i. multifiliis infections were examined experimentally. incomplete resistance to infection was established, the degree of which did not depend on the intensity of the initial infection. resistance was maintained for longer periods, however, by those fish with higher initial levels of infection. previous experience of infection by their hosts had a significant, though sm ...19863097601
production and preliminary characterization of murine monoclonal antibodies to ichthyophthirius multifiliis, a protozoan parasite of fish.an initial panel of 34 hybridomas, each secreting antibodies reactive with an infective theront stage of an ichthyophthirius multifiliis isolate, was produced. three of these cell lines, each producing immunoglobulin m class antibodies, were cloned by limiting dilution and were expanded as ascites-producing tumors in syngeneic mice. three monoclonal antibodies (mab) reacted with intact whole theronts in an enzyme-linked immunosorbent assay to dilutions of 1:10,000 in ascitic fluids and had a sim ...19862431637
[occurrence and significance of ichthyophthirius multifiliis in switzerland]. 19873109029
ichthyophthirius multifiliis (ciliophora) exit from gill epithelium.the first change in the sequence of morphological events occurring as fully developed ichthyophthirius multifiliis trophonts spontaneously left gill epithelium or as younger trophonts departed, following experimentally induced death of the fish, was the separation of parasites from overlying host cells. discharge of contractile vacuoles may have played a role in this process. spaces then appeared between host cells, and individual epithelial cells became vacuolated. finally, the epithelium ruptu ...19873116222
immune response of channel catfish to ciliary antigens of ichthyophthirius multifiliis.channel catfish were rendered immune to the protozoan pathogen, ichthyophthirius multifiliis, by exposure to sublethal infections. sera from test animals were then screened for antibodies against the parasite using enzyme-linked immunoassays. ichthyophthirius cilia were blotted onto nitrocellulose filters and reacted with catfish sera, followed by rabbit anti-catfish ig antibodies coupled to horseradish peroxidase. subsequent color development revealed the presence of anti-ciliary antibodies in ...19883139473
ichthyophthirius (ciliophora): population studies suggest reproduction in host epithelium.evidence that ichthyophthirius multifiliis trophonts may reproduce within the epithelium of the host was obtained from experimental infections of channel catfish. mean number of parasites spontaneously leaving the fish increased from 0 on day 3 postexposure (pe) to 66.5 per fish on day 7 pe. mean population density in fin, however, increased five-fold from day 3 to day 5 pe in the absence of opportunity for reinfection. at day 3 pe, 100% of parasite loci in fin and gill arches contained solitary ...19883143828
icthyophthirius multifiliis has membrane-associated immobilization antigens.sera from fish that survive infections with the ciliated protozoon, ichthyophthirius multifiliis, immobilize the parasite in vitro. in order to identify cell surface antigens involved in the immobilization response, integral membrane proteins were extracted from tomites with triton x-114 and used to immunize rabbits. the rabbit antisera immobilized the parasite in vitro and antigens were localized to cell and ciliary plasma membranes by indirect immunofluorescent microscopy. the membrane protein ...19892470899
[the immunological reactions of fishes to parasite infection under different temperature conditions].the dependence of immunological reactions of fishes infected with ichthyophthirius multifiliis infusoria was elucidated. the invasion of the parasite results in the activation of the immune system, increased phagocytosis and a growth of the activity of oxydase enzymes. with the increased number and sizes of parasites a decrease of the above parameters below the control values is observed. changes of the immunological values are most dynamic at high (20-25 degrees) and they are slower at low (10 ...19902120670
enzyme cytochemistry of the alveolar sacs and golgian-like cisternae in the ciliate ichthyophthirius multifiliis.in the cell cortex of the parasitic ciliate ichthyophthirius multifiliis different kinds of cisternae were observed: the alveolar sacs, thick membrane cisternae and the endoplasmic reticulum. the thick membrane cisternae possess coated dilated rims and sometimes could be observed close to the endoplasmic reticulum. using cytochemical techniques acid phosphatase, thiamine pyrophosphatase and nucleoside diphosphatase activities were detected in the thick membrane cisternae and in the alveolar sacs ...19902162959
purification and partial characterization of immobilization antigens from ichthyophthirius multifiliis.ichthyophthirius multifiliis, a parasitic ciliate of freshwater fishes, was found to have surface antigens (ag) which elicited immobilizing antibodies (ab) when injected into rabbits. an effort was made to purify and characterize these ag (referred to as immobilization ag) because of their potential role in protective immunity in fishes. mice immunized with theront cilia were used for production of immobilizing monoclonal antibodies (mab). hybridomas were screened by indirect immunofluorescent l ...19921383510
the cellular proliferative response, humoral antibody response, and cross reactivity studies of tetrahymena pyriformis with ichthyophthirius multifiliis in juvenile carp (cyprinus carpio l.).the immune response of 10-12-week-old juvenile carp to t. pyriformis [ccap 1630/w, 1939 (w)] was investigated. the humoral antibody response following one and two intraperitoneal injections of whole live t. pyriformis (protein concentration of 25 micrograms/g body weight), separated by an interval of 4 weeks, was monitored over 12-16 weeks. peak antibody titres were detected 6 weeks following antigen administration. antibody titres were elevated following the second injection, and relatively hig ...19921505691
treatment of fish parasites. 9. effects of a medicated food containing malachite green on ichthyophthirius multifiliis fouquet, 1876 (hymenostomatida, ciliophora) in ornamental fish.for systemic therapy against trophozoites of the skin-inhabiting stage of ichthyophthirius multifiliis in ornamental fish, the latter were fed medicated food flakes containing malachite green once daily for 1-11 days ad libitum. naturally or artificially infected cardinal tetras (paracheirodon axelrodi), blue gouramis (trichogaster trichopterus), or clown loach (botia macracantha) were used in the trials. the fish were maintained in aerated 12.5- or 60-1 aquaria at 23 degrees c. ultrastructural ...19921589426
developmental expression of surface antigen genes in the parasitic ciliate ichthyophthirius multifiliis.a 1.2-kilobase (kb) cdna encoding a major surface antigen of the holotrich ciliate ichthyophthirius multifiliis (an obligate parasite of fish) has been isolated and used as a probe to examine the expression of immobilization antigen (i-antigen) genes in this system. the cdna encodes a predicted protein of 394 amino acids with a tandemly repeated structure characteristic of the i-antigens of the related free-living ciliates paramecium and tetrahymena. as shown by northern hybridization analysis w ...19921631132
invasion and development strategies of ichthyophthirius multifiliis, a parasitic ciliate of fish.like many other parasites, ichthyophthirius multifliis faces critical changes when moving between free-living and parasitic phases. this ciliate alternates between feeding in the epithelium of freshwater fishes and swimming and encysting in fresh water. several organelles appear to play key roles in successful negotiation o f these changes. margaret ewing and katherine kocan discuss a variety of cellular components important in host invasion and development of the parasite, with particular atten ...199215463617
localized leucocyte response to ichthyophthirius multifiliis establishment in immune carp cyprinus carpio l.o-group carp (cyprinus carpio) which had been immunized against ichthyophthirius multifiliis by controlled infections were challenged by topical application of theronts to the caudal fin. the parasites which established were examined ultrastructurally, and host leucocyte responses were compared with those observed in primary infections. in the primary exposure group eosinophils and (to a lesser extent) basophils were the predominant cells infiltrating infection sites. in contrast, parasite devel ...19938291210
serotypic variation among isolates of ichthyophthirius multifiliis based on immobilization.efforts have been made to determine whether surface antigens could be used as biochemical markers to define strain differences in the parasitic ciliate ichthyophthirius multifiliis. in previous studies, a wild-type isolate designated g1 was found to have surface proteins analogous to the immobilization antigens of paramecium and tetrahymena; rabbit antiserum against this strain immobilizes homologous cells in vitro. it has now been shown for two additional ichthyophthirius isolates (designated g ...19938293000
processing of food vacuoles in the parasitic ciliate ichthyophthirius multifiliis after exit from the host.the digestive cycle of the fish parasite ichthyophthirius multifiliis (ciliophora) can be divided into three main stages. during stage a the vacuoles are not yet condensed. this stage can be subdivided into an early phase in which food vacuoles contain almost intact fish cells and a later phase in which dense material accumulates at the periphery of the vacuoles. at stage b, food vacuoles attain a very high density, and at stage c the vacuole expands when the membrane pulls away from a condensed ...19938327449
ultrastructural and cytochemical identification of peroxisomes in the ciliate ichthyophthirius multifiliis.the peroxisomes of the parasitic ciliate ichthyophthirius multifiliis were studied, using ultrastructural and cytochemical techniques. in this ciliate most peroxisomes possess a circular or oval section less than 0.6 micron in diameter. however, some dumbbell-shaped and elongated peroxisomes could also be observed. these organelles were frequently associated with the mitochondria and were more abundant in the cell cortex than in the center of the ciliate. small vesicles and dense nucleoids were ...19938461889
[the population level and distribution of ectoparasites in carp].the abundance and the distribution of dactylogyrus extensus and ichthyophthirius multifiliis on gills of two-years old carps have been investigated. it has been established that at least there are five groups, which differs from each other on the asymmetry of infection.19938488057
relationships between the parasites of some wild and cultured fishes in two lakes and a fish farm in central finland.a total of 526 atlantic salmon and 500 brown trout from a fish farm were studied for parasites, as were 272 roach, 251 perch and 150 whitefish from the lake which formed the water source, and 196 roach and 136 perch from the effluent recipient lake. the cultured fish harboured 14 parasite species, of which most were protozoan generalist parasites. nine species were found on salmon and 12 on brown trout. epizootically the most important species were ichthyobodo necator, chilodonella cyprini and i ...19948021098
localized cellular responses to ichthyophthirius multifiliis: protection or pathogenesis?the ciliate ichthyophthirius multifiliis is an economically important parasite in aquaculture as well as in the ornamental fish trade. the parasite has been well studied and details of life cycle, host response and pathogenesis have been characterized. parasite development within host epithelial tissues initiates localized leukocytic infiltrations, although the relationship between these responses and host resistance is uncertain, and whether or not leukocyte responses play a role in protective ...199415275420
parasite infections in danish trout farms.samples from 5 danish freshwater trout farms rearing rainbow trout (oncorhynchus mykiss) were examined for parasite infections from october 1993 until november 1994 and recorded parasites are listed. in addition, results from an examination of a mariculture net cage system are presented as well. a total of 10 metazoan and 10 protozoan parasites were recorded. the metazoans included gyrodactylus derjavini, gyrodactylus salaris, eubothrium crassum, triaenophorus nodulosus, proteocephalus sp., dipl ...19957502946
phylogeny of the fish parasite ichthyophthirius and its relatives ophryoglena and tetrahymena (ciliophora, hymenostomatia) inferred from 18s ribosomal rna sequences.phylogenetic relationships within the subclass hymenostomatia were inferred from the comparisons of three new ssrrna gene sequences from ichthyophthirius multifiliis (1,751 bp), ophryoglena catenula (1,748 bp), and tetrahymena corlissi (1,753 bp). using maximum-parsimony and distance-matrix methods, ichthyophthirius and ophryoglena were consistently paired and formed a sister group to the tetrahymenines, consistent with their placement in the ophryoglenina. tetrahymenids formed a monophyletic gr ...19957700154
sustained growth of ichthyophthirius multifiliis at low temperature in the laboratory.applied and basic research on the ciliate ichthyophthirius multifiliis, an obligate parasite of freshwater fishes, requires passage on fish hosts to maintain laboratory stocks. however, continual repeated passage results in senescence of parasite clones over time. because growth and development are directly correlated to water temperature, our objective was to grow the parasite at low temperature in order to extend the period that the organism remains on the fish, thus reducing: (1) the number o ...19958544046
surface antigen cross-linking triggers forced exit of a protozoan parasite from its host.we used the common fish pathogen ichthyophthirius multifiliis as a model for studying interactions between parasitic ciliates and their vertebrate hosts. although highly pathogenic, ichthyophthirius can elicit a strong protective immune response in fish after exposure to controlled infections. to investigate the mechanisms underlying host resistance, a series of passive immunization experiments were carried out using mouse monoclonal antibodies against a class of surface membrane proteins, known ...19968692903
the control of ichthyophthiriasis by a medicated food containing quinine: efficacy tests and ultrastructure investigations.the present report demonstrates that a medicated food containing quinine kills the skin-inhabiting trophozoite stage of ichthyophthirius multifiliis in ornamental fish. artificially infected swordtails. (xiphophorus helleri), black mollies (poecilia sphenops), and black neons (hyphessobrycon herbertaxelrodi) were used in the trials. the fish were maintained in groups of 10 or 20 inside aquaria (20 or 60 l) at 25 degrees c. ultrastructure investigations by means of transmission electron microscop ...19968897504
passive immunization of channel catfish (ictalurus punctatus) against the ciliated protozoan parasite ichthyophthirius multifiliis by use of murine monoclonal antibodies.fish acquire immunity against the ciliated protozoan parasite ichthyophthirius multifiliis following sublethal infection. the immune response includes the elaboration of humoral antibodies against a class of abundant surface membrane proteins referred to as immobilization antigens (i-antigens). antibodies against these proteins immobilize the parasite in vitro, suggesting a potential role for the i-antigens in protective immunity. to test this hypothesis, passive immunization experiments were ca ...19968926073
epizootiology of protozoans in farmed salmonids at northern latitudes.protozoan ectoparasites were examined in a northern salmonid fish farm over a 10-year period, june 1984-may 1994, by the same researcher, with similar catching and sampling procedures throughout. husbandry procedures remained constant during the study, e.g., fingerlings were kept in steel tanks and yearlings in both steel tanks and earth ponds. ichthyobodo necator, chilodonella hexasticha and ichthyophthirius multifiliis infections were treated with formalin, salt and malachite green-formalin ba ...19979076534
immunization against parasitic diseases of fish.parasitologists have not, in the past, exploited the immune system to protect fish against parasitic diseases. in the past few years, however, there has been an increased interest in adopting this strategy, and we have made steady and promising progress against a few parasites which are of economic importance. amyloodinium ocellatum is an ectoparasitic dinoflagellate on brackish and marine fishes, which may also cause problems to aquarium fishes. antiserum from fish inoculated intraperitoneally ...19979270852
antibody-mediated effects on parasite behavior: evidence of a novel mechanism of immunity against a parasitic protist.the parasitic ciliate ichthyophthirius multifiliis is well known in commercial aquaculture as the etiological agent of 'white spot', a disease that afflicts a wide range of fresh-water fish. while ichthyophthirius is highly pathogenic, animals exposed to controlled infections develop a strong acquired resistance to the parasite. recent studies suggest host resistance involves a novel mechanism of humoral immunity affecting parasite behavior. rather than being killed, parasites are forced to exit ...199715275136
theronts of ichthyophthirius multifiliis find their fish hosts with complex behavior patterns and in response to different chemical signals.how parasites find and recognize fish hosts is best known for trematode cercariae. these multicellular organisms respond with complex behavior patterns to sequences of different chemical host signals, although these invasive stages are produced in large numbers. however, little is known on the host-finding of protozoan parasites. we therefore studied how the infective theronts of i. multifiliis find their fish hosts by offering them various fractions and chemical modifications of fish skin surfa ...199810622630
ichthyophthirius multifiliis: a model of cutaneous infection and immunity in fishes.the parasitic ciliate ichthyophthirius multifiliis offers a useful system for the study of cutaneous immunity against an infectious microorganism. naive fish usually die following infection, but animals surviving sublethal parasite exposure become resistant to subsequent challenge. this resistance correlates with the presence of humoral antibodies in the sera and cutaneous mucus of immune fish. a mechanism of immunity has recently been elucidated that involves antibody binding to surface protein ...19989914927
the gene for an abundant parasite coat protein predicts tandemly repetitive metal binding domains.immobilization antigens are highly abundant surface membrane proteins that coat the surface of hymenostomatid ciliates. while their function is unknown, recent studies with the common fish parasite, ichthyophthirius multifiliis, suggest their involvement in a novel mechanism of humoral immunity involving an effect of antibody on parasite behavior. to gain further insight into the nature of these proteins, we have cloned a gene encoding the 48kda i-antigen of i. multifiliis. analysis of the gene ...199910095108
surface display of a parasite antigen in the ciliate tetrahymena thermophila.the ciliated protozoan, tetrahymena thermophila, offers an attractive medium for the expression of heterologous proteins and could prove particularly useful for the display of foreign proteins on the cell surface. although progress has been made in transformation of tetrahymena with heterologous dna, methods that permit reliable expression of foreign genes have been lacking. using a mutant strain of t. thermophila carrying a negatively selectable allele of a beta-tubulin gene, we have been able ...199910331805
experimental infection of striped marshfrog tadpoles (limnodynastes peronii) by ichthyophthirius multifiliis.ichthyophthirius multifiliis, or white spot, is a well known and widely distributed parasite of freshwater fish. however, it is not know whether it can infect other aquatic vertebrates such as amphibians. this study uses a series of laboratory-based experiments to demonstrate that i. multifiliis can infect the tadpole stage of an amphibian, the striped marshfrog (limnodynastes peronii) of eastern australia. the tadpoles did not appear to develop ichthyophthiriasis at low parasite levels (200 par ...199910386457
ichthyophthiriasis in carp cyprinus carpio: infectivity of trophonts prematurely exiting both the immune and non-immune host.ichthyophthirius multifiliis exposed to naturally immunised carp established short-term infections, the majority of parasites actively emerging within 2 h of entering the epidermis. a small, but significant, number of these expelled parasites were shown to retain theront-like properties with the capacity to directly re-invade a further fish host. infectivity fell rapidly with time in the host and was comparable to that of trophonts of a similar age artificially induced to emerge from non-immune ...199910401585
parasites in cultured and feral fish.parasites, causing little apparent damage in feral fish populations, may become causative agents of diseases of great importance in farmed fish, leading to pathological changes, decrease of fitness or reduction of the market value of fish. despite considerable progress in fish parasitology in the last decades, major gaps still exist in the knowledge of taxonomy, biology, epizootiology and control of fish parasites, including such 'evergreens' as the ciliate ichthyophthirius multifiliis, a causat ...199910456421
partial cross protection against ichthyophthirius multifiliis in gyrodactylus derjavini immunized rainbow trout.partial cross protection against a skin-parasitic ciliate has been recorded in rainbow trout previously immunized with an ectoparasitic platyhelminth. the susceptibility to infection by ichthyophthirius multifiliis differed significantly between naive and gyrodactylus derjavini immunized rainbow trout. fish partly immune to the ectoparasitic monogenean g. derjavini became less infected and experienced lower mortality than naive fish when exposed to i. multifiliis infections. in vitro studies on ...199910526411
chemoattraction of ichthyophthirius multifiliis (ciliophora) theronts to host molecules.mechanisms in the host-finding process of ichthyophthirius multifiliis were studied in vitro by a novel bioassay using 24-well multidishes supplied with bottom layers of agar with chemoattractants. it was shown that low molecular weight molecules (carbohydrates, amino acids, fatty acids, urea) did not attract theronts. in contrast, sera and mucus from a range of teleosts (including marine fish) were effective attractants. fractionation by gel filtration of fish serum allowed determination of the ...199910579427
characterization of histone h3/h4 gene region and phylogenetic affinity of ichthyophthirius multifiliis based on h4 dna sequence variation.we sequenced the amino-terminal third of the histone h3 and h4 genes and the intergenic region from ichthyophthirius multifiliis. fourteen recombinant clones of 646 bp were sequenced and the level of sequence variation detected among these clones was similar to that reported among closely related species of tetrahymena and to levels of sequence variation detected within other ciliates. the intergenic region is 417 bp and approximately 92% at rich, making it the longest and most at-rich ciliate h ...200010712850
associations between epidermal thionin-positive cells and skin parasitic infections in brown trout salmo trutta.the dynamics of the densities of epidermal thionin-positive cells (putative mast cells) in the skin of brown trout fry were investigated during experimental infections with the skin parasites ichthyophthirius multifiliis (ciliophora) and gyrodactylus derjavini (monogenea). it was shown that the metachromatic thionin-stained cells were extremely sensitive to parasite exposure, as the density of cells in the skin of trout decreased markedly after exposure to the pathogens. as early as 7 d post inf ...200010918981
prolonged in vitro cultivation of ichthyophthirius multifiliis using an epc cell line as substrate.the ciliate ichthyophthirius multifiliis, which normally requires a fish host to develop from the theront stage to the trophont stage, was cultivated in vitro for part of its life cycle. experiments were conducted using a laboratory strain of the parasite originally isolated from rainbow trout oncorhynchus mykiss in a danish trout farm. theronts escaping from tomontocysts were kept in water, cell culture media (e-mem or l-15), or cultures of epc (epithelioma papulosum cyprini) cells in plastic t ...200011104073
occurrence of ichthyophthirius multifiliis within the peritoneal cavities of infected channel catfish ictalurus punctatus.ichthyophthirius multifiliis is a ciliated protozoan parasite that infects the skin and gills of freshwater fish. this report describes the unusual finding of i. multifiliis within the peritoneal cavities of experimentally infected channel catfish ictalurus punctatus. twenty catfish fingerlings were exposed to i. multifiliis theronts using a standardized protocol. five infected fish and 2 control fish were killed at various time points after infection and their tissues examined. formalin-fixed, ...200111253873
the i-antigens of ichthyophthirius multifiliis are gpi-anchored proteins.the parasitic ciliate ichthyophthirius multifiliis has abundant surface membrane proteins (i-antigens) that when clustered, trigger rapid, premature exit from the host. similar antigens are present in free-living ciliates and are gpi-anchored in both paramecium and tetrahymena. although transmembrane signalling through gpi-anchored proteins has been well-documented in metazoan cells, comparable phenomena have yet to be described in protists. since premature exit of ichthyophthirius is likely to ...200111411842
effect of lectins on the invasion of ichthyophthirius theront to channel catfish tissue.this study determined the effects of lectin binding to theronts of ichthyophthirius multifiliis on theront immobilization, invasion, trophont development and survival in channel catfish ictalurus punctatus excised fins in vitro. soybean agglutinin (sba), lentil agglutinin (lca), gorse agglutinin (uea-i) and wheat germ agglutinin (wga) were used to treat theronts. percentages of theronts immobilized by 4 lectins ranged from 12.0 to 19.4% at a concentration of 1000 microg ml(-1). these lectins bou ...200111463098
host responses against the fish parasitizing ciliate ichthyophthirius multifiliis.recent studies have shown that fish are able to mount protective immune responses against various parasites. one of the best characterized parasite-host system in this context is the ciliate ichthyophthirius multifiliis (ich) parasitizing a range of freshwater fishes. both specific and non-specific host defence mechanisms are responsible for the protection of fish against challenge infections with this ciliate. the specific humoral components comprise at least specific antibodies. the non-specif ...200111522410
surface immobilization antigen of the parasitic ciliate ichthyophthirius multifiliis elicits protective immunity in channel catfish (ictalurus punctatus).channel catfish (ictalurus punctatus) that survive infection with the parasitic ciliate ichthyophthirius multifiliis acquire immunity to subsequent challenge and produce specific antibodies in serum that immobilize the parasite in vitro. cellular surface protein antigens targeted by these antibodies are referred to as immobilization antigens (i-antigens). by using an immobilizing mouse monoclonal antibody as a ligand, the i-antigen of i. multifiliis isolate g5 was purified to homogeneity by immu ...200211777850
variation in primary sequence and tandem repeat copy number among i-antigens of ichthyophthirius multifiliis.the immobilization antigens (i-antigens) of ichthyophthirius multifiliis are potential vaccine candidates for the prevention of 'white spot' disease in freshwater fish. these antigens vary with respect to antigenicity and molecular mass, and at least five i-antigen serotypes have been identified among parasite isolates thus far. in previous studies, the gene and corresponding cdna encoding a approximately 48 kda i-antigen from parasite isolate g1 (serotype a), had been cloned and sequenced. we n ...200211849709
a robust inducible-repressible promoter greatly facilitates gene knockouts, conditional expression, and overexpression of homologous and heterologous genes in tetrahymena thermophila.the cd(2+)-inducible metallothionein (mtt1) gene was cloned from tetrahymena thermophila. northern blot analysis showed that mtt1 mrna is not detectable in the absence of cd(2+), is induced within 10 min of its addition, is expressed in proportion to its concentration, and rapidly disappears upon its withdrawal. similarly, when the neo1 gene coding region flanked by the mtt1 gene noncoding sequences was used to disrupt the mtt1 locus, no transformants were observed in the absence of cd(2+), and ...200211891286
the use of synthetic genes for the expression of ciliate proteins in heterologous systems.the common fish parasite, ichthyophthirius multifiliis, expresses abundant glycosylated phosphatidylinositol (gpi)-anchored membrane proteins known as immobilization antigens, or i-antigens. these proteins are targets of the host immune response, and have been identified as potential candidates for recombinant subunit vaccine development. nevertheless, because ichthyophthirius utilizes a non-standard genetic code, expression of the corresponding gene products, either as subunit antigens in conve ...200212034497
comparing tolerance of ichthyophthirius multifiliis and tetrahymena thermophila for new cryopreservation methods.ichthyophthirius multifiliis is an obligate protozoan parasite of freshwater fishes that has a complex developmental cycle. it has not been successfully cryopreserved, so management studies are restricted to parasites obtained during outbreaks or perpetuated by passage in live fishes. to overcome this serious limitation, free-swimming i. multifiliis parasites were tested in a cryopreservation protocol routinely used for a related ciliate, tetrahymena. in this protocol, i. multifiliis theronts re ...200212053978
immunisation of channel catfish, ictalurus punctatus, with ichthyophthirius multifiliis immobilisation antigens elicits serotype-specific protection.surface immobilisation antigens (i-antigens) were purified from two strains of ichthyophthirius multifiliis (ny1 and g5) that represent different i-antigen serotypes, namely a and d, respectively. the efficacy of the purified antigens as subunit vaccines was then tested in challenge studies using parasites of the homologous or heterologous serotype. three groups of juvenile channel catfish (70 animals per group) were immunised with i-antigens from either the g5 or ny1 isolates, or with bovine se ...200212458741
parasitic infections in live freshwater tropical fishes imported to korea.we examined 15 species of ornamental tropical fishes originating from southeast asia to determine the cause of losses among 8 fish farms in korea. a total of 351 individuals belonging to 5 different families (1 species of characidae, 6 of cichlidae, 3 of cyprinidae, 1 of heleostomatidae, and 4 of poecilidae) were collected for the purpose of detecting metazoan and protozoan parasites. parasites were fixed and stained using routine methods, and identified. we found 3 ciliates, 2 monogeneans, 1 ne ...200212542094
ichthyophthirius multifiliis and tetrahymena thermophila tolerate glyphosate but not a commercial herbicidal formulation. 200312677384
parasitic infections in freshwater ornamental fish in sri lanka.a total of 1520 ornamental fish of 13 species from 26 export farms in sri lanka were collected between october 1999 and march 2000 and examined for parasites. fish species examined were guppy poecilia reticulata, goldfish carassius auratus, platy xiphophorus maculatus, molly poecilia sphenops, angel pterophyllum scalare, swordtail xiphophorus helleri, tetras hyphessobrycon species, barbs capeota and puntius spp., gourami colisa sp., carp cyprinus carpio, fighters betta spelendens and others (bra ...200312747641
efficacy of selected oral chemotherapeutants against ichthyophthirius multifiliis (ciliophora: ophyroglenidae) infecting rainbow trout oncorhynchus mykiss.the chemotherapeutic efficacy of 6 in-feed compounds against ichthyophthirius multifiliis fouquet, 1876 was assessed using experimental infections of rainbow trout oncorhynchus mykiss (walbaum) fingerlings. trial doses of 104 ppm amprolium hydrochloride or 65 ppm clopidol fed to fish for 10 d prior to infection significantly reduced the number of trophonts establishing in trout fingerlings by 62.0 and 35.2% respectively. in-feed treatments of infected trout with either 63 or 75 ppm amprolium hyd ...200312887250
protective effect of cutaneous antibody produced by channel catfish, ictalurus punctatus (rafinesque), immune to ichthyophthirius multifiliis fouquet on cohabited non-immune catfish.fish which survive a sublethal ichthyophthiriasis acquire protective immunity against ichthyophthirius multifiliis fouquet (ich). this study evaluated the protective effect of cutaneous antibody secreted by channel catfish, ictalurus punctatus (rafinesque), immune to ich on cohabited non-immune catfish. non-immune and immune fish controls were separately maintained and infected with theronts. the ich infection was assessed by scoring 0, < 50, 50-100, and > 100 trophonts fish(-1) at 5 days post-i ...200312962237
systemic and cutaneous mucus antibody responses of channel catfish immunized against the protozoan parasite ichthyophthirius multifiliis.fish acquire protective immunity against the ciliated protozoan parasite ichthyophthirius multifiliis following sublethal infection or inoculation with i. multifiliis immobilization antigens (i-antigens). in both cases, parasite-immobilizing antibodies have been identified in sera and mucosal secretions. to investigate the kinetics of this immune response, antibody levels were determined by enzyme-linked immunosorbent assay (elisa) in the sera and cutaneous mucus of channel catfish (ictalurus pu ...200312965920
parasite communities as indicators of recovery from pollution: parasites of roach (rutilus rutilus) and perch (perca fuviatilis) in central finland.we compared parasite communities in fish taken from a polluted lake (l. vatia) and two control lakes before (1986) and after (1995) nine years of markedly reduced chemical and nutrient loading from a pulpmill in central finland. discriminant analyses of the 1995 data, using a function based on the 1986 data, showed that the parasite communities in the fish from the two control lakes had changed relatively little, whereas those from l. vatia had converged on those from the mesotrophic control lak ...200314667171
cadmium effects on ichthyophthirius: evidence for metal-sequestration in fish tissues following administration of recombinant vaccines.we are developing tetrahymena thermophila as a delivery system for recombinant vaccines against parasitic protozoa, including the common fish parasite, ichthyophthirius multifiliis. t. thermophila cell lines expressing i. multifiliis genes under the control of a cadmium-inducible metallothionein gene promoter conferred strong protection against a lethal parasite challenge when administered parenterally to naive fish. nevertheless, given that heavy metals can be toxic to parasites, a question aro ...200314667175
effects of crude extracts of mucuna pruriens (fabaceae) and carica papaya (caricaceae) against the protozoan fish parasite ichthyophthirius multifiliis.the ciliate ichthyophthirius multifiliis is among the most pathogenic parasites of fish maintained in captivity. in the present study, the effects of the crude methanolic extract of leaves of mucuna pruriens and the petroleum-ether extract of seeds of carica papaya against i. multifiliis were investigated under in vivo and in vitro conditions. goldfish (carassius auratus auratus) infected with the parasites were immersed for 72 h in baths with m. pruriens extract, and for 96 h in baths with c. p ...200414735356
immune responses and host protection of channel catfish, ictalurus punctatus (rafinesque), against ichthyophthirius multifiliis after immunization with live theronts and sonicated trophonts.the humoral immune responses and host protection of channel catfish, ictalurus punctatus (rafinesque), against ichthyophthirius multifiliis (ich) were determined after immunization with live theronts and sonicated trophonts. immunizations with live theronts or sonicated trophonts were carried out by both bath immersion and intraperitoneal (i.p.) injection. cutaneous and serum immunoglobulin (ig) levels and anti-ich antibodies were measured 12 and 21 days post-immunization. the level of ich infec ...200415009239
expression of pro-inflammatory cytokines in rainbow trout (oncorhynchus mykiss) during an infection with ichthyophthirius multifiliis.inflammatory processes are known to take place in the skin of fish during an infection with the parasitic ciliate ichthyophthirius multifiliis. the present study shows that the pro-inflammatory cytokines interleukin 1 beta (il-1beta) and tumor necrosis factor alpha (tnf-alpha), the chemokine interleukin 8 (il-8) and the type ii il-1 receptor (il-1rii) are expressed in rainbow trout during an infection. in the skin an up to 17.8 times increase in the expression level of il-1beta relative to uninf ...200415145419
two year study on the infectivity of ichthyophthirius multifiliis in channel catfish ictalurus punctatus.ichthyophthirius multifiliis fouquet (ich) is a fish parasite that causes serious economic loss for aquaculture. a major difficulty in the maintenance of single isolates of ich for research purposes is the loss of infectivity. after an unknown number of passages or infection cycles the ich isolate loses its infectivity. this study determined the infectivity of an ich isolate during 105 infection cycles in channel catfish ictalurus punctatus over a 2 yr period. the mean percentage of fish infecte ...200415212279
the parasitic ciliate ichthyophthirius multifiliis induces expression of immune relevant genes in rainbow trout, oncorhynchus mykiss (walbaum).abstract during an infection with the parasitic ciliate ichthyophthirius multifiliis, expression of genes encoding complement factor c3, inducible nitric oxide synthase (inos), immunoglobulin (igm) and major histocompatibility complex (mhc-ii) was examined in the skin, head kidney and spleen of rainbow trout using semi-quantitative reverse transcriptase-polymerase chain reaction. induction of c3 transcription levels was evident in the skin and spleen showing extra-hepatic production of c3. mhc-i ...200415228610
role of ichthyophthirius multifiliis in the infection of aeromonas hydrophila.aeromonas hydrophila and ichthyophthirius multifiliis are important fish pathogens. to clarify their relationship, two host models, goldfish with trauma and those infected with i. multifiliis, were used to study infection kinetics of a. hydrophila 4332 tagged with plasmid pgfpuv (ah4332(gfp)). the results showed that in fish suffering from ichthyophthiriosis, the bacterial infection process was accelerated and more persistent than in the other groups. it is suggested that i. multifiliis plays an ...200415330981
influence of anguillicola crassus (nematoda) and ichthyophthirius multifiliis (ciliophora) on swimming activity of european eel anguilla anguilla.we investigated the swimming activity of 70 european eels anguilla anguilla in relation to natural infection with 2 parasite species: the eel-specific swimbladder nematode anguillicola crassus and the non-specific skin and gill protozoan ichthyophthirius multifiliis. we measured how long individual eels exposed to a water current in a swimming channel with a steady-stream profile could withstand the water current. the parasites affected the swimming behaviour of eels in different ways. the maxim ...200415460857
cutaneous antibodies from channel catfish, ictalurus punctatus (rafinesque), immune to ichthyophthirius multifiliis (ich) may induce apoptosis of ich theronts.this study explored the existence of apoptosis (programmed cell death) in ichthyophthirius multifiliis fouquet (ich) theronts and determined the effect of cutaneous antibodies in skin culture fluid from fish immune to ich on theront apoptosis. apoptosis was detected in theronts and was clearly distinguished by fluorescent microscopy after staining with acridine orange and propidium iodide. the apoptotic theronts showed characteristic chromatin condensation and nuclear fragments containing chroma ...200515813863
treatment of ichthyophthiriasis after malachite green. i. concrete tanks at salmonid farms.since the use of malachite green was banned in many european countries, new alternative treatments have been tested to prevent white spot disease caused by ichthyophthirius multifiliis. we tested formalin, potassium permanganate (kmno4), chloramine-t, hydrogen peroxide (h2o2) and per aqua or desirox alone or in combinations of 2 chemicals, one of which was always formalin, in 50 m2 concrete tanks at 2 farms producing salmon salmo salar smolt in 2001 and 2002. both per aqua and desirox are combin ...200515900690
non-invasive detection and quantification of the parasitic ciliate ichthyophthirius multifiliis by real-time pcr.the main parasitic threat to freshwater fish is the ciliate ichthyophthirius multifiliis. we developed a real-time pcr assay using sybr green intercalating fluorescent dye for rapid detection and quantification of i. multifiliis. this non-invasive assay was based on the quantification of i. multifiliis free-swimming stages from filtered water samples, and thus made it possible to preserve host individuals. an alignment of 18s rdna sequences of i. multifiliis and related species of the ciliate or ...200516119894
treatment of ichthyophthiriasis after malachite green. ii. earth ponds at salmonid farms.we tested formalin, chloramine-t-formalin and desirox-formalin, for use against white spot disease (ichthyophthiriasis) caused by ichthyophthirius multifiliis at 3 salmonid farms (salmo salar and s. trutta smolt reared in earth ponds). i. multifiliis disappeared from most individuals 4 to 5 wk after the first treatment (and after the first i. multifiliis were found) with all chemicals, indicating that combinations of these chemicals, and even formalin alone, can be used to lower the parasite bur ...200516175963
ichthyophthirius multifiliis fouquet and ichthyophthiriosis in freshwater teleosts.the ciliate ichthyophthirius multifiliis is an important pathogen of freshwater teleosts occurring in both temperate and tropical regions throughout the world. the disease, ichthyophthiriosis, accounts for significant economic losses to the aquaculture industry, including the ornamental fish trade, and epizootics in wild fish populations can result in mass kills. this review attempts to provide a comprehensive overview of the biology of the parasite, covering the free-living and parasitic stages ...200516182866
characterization of cryptocaryon irritans isolates from marine fishes in mainland china by its ribosomal dna sequences.seven isolates of cryptocaryon irritans from different host species and geographical locations in mainland china were characterized by the first (its-1) and second (its-2) internal transcribed spacers (its) of nuclear ribosomal dna (rdna) using two isolates of ichthyophthirius multifiliis for comparative purposes. the rdna region including the its-1, 5.8s, its-2, and flanking 18s and 28s sequences were amplified by polymerase chain reaction and the amplicons were sequenced directly. the its-1, 5 ...200616523350
induced cross-protection in channel catfish, ictalurus punctatus (rafinesque), against different immobilization serotypes of ichthyophthirius multifiliis.abstract channel catfish, ictalurus punctatus (rafinesque), were immunized with ichthyophthirius multifiliis (ich) theronts and trophonts, and the immune response and host protection against both homologous and heterologous serotypes of ich were evaluated. immunizations were done with two immobilization serotypes (ars4 and ars6) of live theronts by bath immersion (trial i) and with sonicated trophonts by intraperitoneal (i.p.) injection (trial ii). cutaneous and serum antibody titres against ich ...200616533298
secretion of functional human enzymes by tetrahymena thermophila.the non-pathogenic ciliate tetrahymena thermophila is one of the best-characterized unicellular eucaryotes used in various research fields. previous work has shown that this unicellular organism provides many biological features to become a high-quality expression system, like multiplying to high cell densities with short generation times in bioreactors. in addition, the expression of surface antigens from the malaria parasite plasmodium falciparum and the ciliate ichthyophthirius multifiliis su ...200616542419
apoptosis in ichthyophthirius multifiliis is associated with expression of the fas receptor of theronts.the expression of type i membrane fas receptors on the surface of ichthyophthirius multifiliis (ich) theronts and the possible association between fas expression and theront apoptosis induced by the immune antibody was examined. fas receptors were detected on the theront surface using fluorescein isothiocyanate-conjugated mouse monoclonal antibody against fas. fas-positive theronts significantly increased with time during in vitro incubation and with increasing theront concentration. furthermore ...200616635062
differences in virulence between two serotypes of ichthyophthirius multifiliis.naive channel catfish ictalurus punctatus were infected by 2 isolates of the parasitic ciliate ichthyophthirius multifiliis that differed in virulence. the isolates, ny1 and g5, serotypes a and d, respectively, express different surface immobilization-antigens. the virulence of the 2 isolates was compared using tail-fin infections to quantitate parasite numbers and by analysis of the survival of infected fish. although ny1 infected fish at a lower level than g5, all ny1-infected fish died, but 5 ...200616724566
temperature-dependent protection against ichthyophthirius multifiliis following immunisation of rainbow trout using live theronts.rainbow trout oncorhynchus mykiss walbaum, 1792 fingerlings were vaccinated by intraperitoneal (i.p.) injection using live theronts of the skin parasitic ciliate ichthyophthirius multifiliis fouquet, 1876 at 2 temperatures (12 and 20 degrees c), and protection against challenge infections was subsequently evaluated by bath exposure to live theronts. vaccination conferred a relative protection (evaluated as the decrease in the number of established theronts) at 12 degrees c and almost complete im ...200617190205
differential expression of cysteine proteases in developmental stages of the parasitic ciliate ichthyophthirius multifiliis.an expressed sequence tag database of the freshwater fish parasite, ichthyophthirius multifiliis (ciliophora) was analyzed to seek for proteases potentially involved in the invasion and degradation of host tissues during infection. the translation of the database revealed two cathepsin l cysteine proteases (icp1 and icp2) of the c1a peptidase subfamily. the analysis of icp1 and icp2 sequences suggested that both proteases would be synthesized as preproproteins, with a mature domain of 27.9 and 2 ...200717227460
cross-immunity and antibody responses to different immobilisation serotypes of ichthyophthirius multifiliis.vaccination of channel catfish with either of two serotypes of the parasitic ciliate ichthyophthirius multifiliis conferred protection against challenge infection by either serotype. fish were vaccinated by intracoelomic injection with live theronts of isolate g5 (serotype d) or isolate g12 (a new serotype), which express different surface immobilisation antigens. vaccination with live g12 theronts conferred complete protection against subsequent challenge by both serotypes while vaccination wit ...200717227714
evaluation of a cohabitation challenge model in immunization trials for channel catfish ictalurus punctatus against ichthyophthirius multifiliis.calcein marking and cohabitation challenges have not been investigated in fish parasite research. this study evaluated a cohabitation challenge method in immunization trials against ichthyophthirius multifiliis (ich) using calcein, a fluorescent dye, to mark channel catfish ictalurus punctatus (rafinesque). fish were marked by calcein immersion at 0, 500, and 1500 mg l(-1), and then challenged with 15 000 theronts fish(-1). no difference was noted in fish infection levels, mortality, and mean da ...200717425263
generation and analysis of expressed sequence tags from the ciliate protozoan parasite ichthyophthirius multifiliis.the ciliate protozoan ichthyophthirius multifiliis (ich) is an important parasite of freshwater fish that causes 'white spot disease' leading to significant losses. a genomic resource for large-scale studies of this parasite has been lacking. to study gene expression involved in ich pathogenesis and virulence, our goal was to generate expressed sequence tags (ests) for the development of a powerful microarray platform for the analysis of global gene expression in this species. here, we initiated ...200717577414
[application of peracetic acid for the treatment of juvenile sander (sander lucioperca) during ichthyophthirius multifiliis infestation].white spot disease caused by the ciliate protozoan parasite ichthyophthirius multifiliis (i. m.), is one of the most dangerous diseases in aquaculture and ornamental fish breeding worldwide. the parasite is characterized by three developmental stages: a reproductive tomont, an infective theront and a parasitic trophont. in sander (sander lucioperca) breeding i. m. causes serious economic losses. after banning of the traditional therapeutic agent malachite green we have to face a state of emergen ...200717724932
[antiparasitic effects of peracetic acid (paa) against infective stages (theronts) of white spot disease, ichthyophthirius multifiliis in vitro].white spot disease, caused by the protozoan parasite ichthyophthirius multifiliis (i. multifiliis), invades nearly all fresh water fish species and causes huge economic losses. in germany no protocide substance is legal for the treatment of i. multifilis. as an alternative substance the peracetic acid (paa) was tested to treat the free invasive stage (theront) of the parasite. paa concentrations of 0.3 ppm were able to kill all theronts in 120 min in our investigations. as a result of these inve ...200717970337
real-time gene expression analysis in carp (cyprinus carpio l.) skin: inflammatory responses caused by the ectoparasite ichthyophthirius multifiliis.real time quantitative pcr (rq-pcr) assays were developed for the measurement of differential real-time expression of immune-related genes in skin and whole blood from cyprinus carpio during an infection with the ectoparasite ichthyophthirius multifiliis. the target genes included the chemokines cxca and cxcb, the chemokine receptors cxcr1 and cxcr2, the pro-inflammatory cytokines interleukin 1 beta (il-1beta) and tumour necrosis factor alpha (tnf-alpha) and the enzymes inducible nitric oxide sy ...200717046281
cutaneous immune responses in the common carp detected using transcript analysis.in order to detect new immune-related genes in common carp (cyprinus carpio l.) challenged by an ectoparasitic infection, two cdna libraries were constructed from carp skin sampled at 3 and 72h after infection with ichthyophthirius multifiliis. in a total of 3500 expressed sequence tags (ests) we identified 82 orthologues of genes of immune relevance previously described in other organisms. of these, 61 have never been described before in c. carpio, thus shedding light on some key components of ...200717049603
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