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1.
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 following immunization were measured and survival of catfish was determined after theront challenge. Theronts were immobilized by the antiserum from fish immunized with homologous theronts or trophonts, but not by the serum of fish immunized with the heterologous serotype. Serum from fish immunized by immersion with live theronts showed higher enzyme-linked immunosorbent assay titres against both homologous and heterologous serotypes than fish immunized by i.p. injection of trophonts. Channel catfish immunized by immersion with live theronts or by i.p. injection with sonicated trophonts developed an immune response against Ich and provided cross-protection against challenge from both serotypes (ARS4 and ARS6) of the parasite. Sonicated trophont antigens in aqueous solution by i.p. injection could stimulate an immune response in fish, but the immunity was of short duration. 相似文献
2.
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 infection and survival of catfish were determined after theront challenge. Cutaneous and serum anti-Ich antibodies were significantly higher (P < 0.05) in fish immunized with live theronts by immersion or i.p. injection, or with sonicated trophonts administered by i.p. injection, than in fish immunized with sonicated trophonts by immersion, with bovine serum albumin by i.p. injection, or non-immunized controls. Host protection was noted only in fish immunized with live theronts by immersion or i.p. injection or with sonicated trophonts by i.p. injection. There was a positive correlation between higher levels of anti-Ich antibodies and host survival in the immunized fish. 相似文献
3.
This study investigated antibody mediated immune response against Ichthyophthirius multifiliis (Ich) by determining whether theronts would retain the potential for reinfection, both in vitro and in vivo, after treatment with the culture fluid of excised skin from channel catfish, Ictalurus punctatus , immune to Ich. The invasion was reduced significantly ( P < 0.05) for theronts treated with the immune culture fluid compared with those treated with the culture fluid from naive fish. The treatment of theronts with the immune culture fluid greatly reduced the size and survival of trophonts compared with those treated with the culture fluid from naive fish. Fewer fish were infected and the infection density was less for fish exposed to theronts treated with immune culture fluid. The infection was severe for fish invaded by theronts treated with the culture fluid from naive fish, with a high number of infected fish and heavy density of trophonts per fish. All fish were infected by Ich when exposed to the theronts treated with the immunoadsorbed culture fluid. In summary, results of this study show that cutaneous antibodies in the culture fluid of excised skin from immune fish significantly reduces theront infectivity by immobilizing or weakening theronts. 相似文献
4.
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 chromatin pieces. The externalization of phosphatidylserine on the plasma membrane of apoptotic theronts was detected with fluorescein isothiocyanate-conjugated annexin using flow cytometry. Theront apoptosis was induced using the skin culture fluid from fish immune to Ich, which contained cutaneous antibodies against Ich. The highest apoptosis appeared in theronts exposed to immune skin culture fluid at a 1:10 dilution, compared with those at 1:20 and 1:40 dilutions. A direct correlation was noted between the percentage of apoptotic theronts and exposure duration to immune skin culture fluid. The study indicated that antibody reaction with theronts (immobilization) played an important role in theront apoptosis, but it could not be excluded that other components released from the excised skin had effects on theronts. 相似文献
5.
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, the immune cutaneous antibody induced theront apoptosis; however, Fas ligand did not. A highly significant correlation was noted between theront Fas expression and immune cutaneous antibody-induced theront apoptosis. Numbers of apoptotic theronts increased with increasing number of Fas-positive theronts. The data indicated that theront apoptosis induced by immune cutaneous antibody appears to be positively correlated with the expression of Fas on the surface of Ich theronts. 相似文献
6.
A family of antimicrobial peptides (AMPs) derived from the β‐subunit of haemoglobin was recently isolated from channel catfish, Ictalurus punctatus, infected with Ichthyophthirius multifiliis (ich), an important freshwater fish parasite that causes ichthyophthiriosis. We previously discovered that one of these AMPs, HbβP‐1, had strong cidal activity against ich as well as another ectoparasite, Tetrahymena pyriformis. HbβP‐1 toxicity was specific, primarily affecting the trophozoite (trophont) stage of ich. Here, we show that HbβP‐1 acts more rapidly to kill smaller (presumably less mature) trophonts of ich, taking almost twice as long to kill larger trophonts (P < 0.0001). It acts more rapidly than an unrelated AMP, piscidin 1, which is haemolytic and also lethal to ich trophonts. HbβP‐1 is potently and selectively lethal to the trophont stage of the dinoflagellate ectoparasite, Amyloodinium ocellatum, one of the most important pathogens of warmwater marine fish. HbβP‐1 has no effect on the fish gill cell line feeder layer (G1B cells) used to propagate Amyloodinium, further suggesting a highly selective action. These findings suggest that HbβP‐1 or related AMPs might function in protecting marine as well as freshwater fish and that HbβP‐1 has highly selective activity against specific life stages of important fish ectoparasites. 相似文献
7.
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-infection. The results of infection showed that cohabited fish at the ratio of 15 non-immune to two immune fish had < 50 trophonts fish(-1). Eighty per cent of the cohabited fish at the ratio of 10 non-immune to two immune fish showed 0 or < 50 trophonts fish(-1). The 76% of control non-immune fish had more than 100 trophonts fish(-1). The control immune fish had 0 trophonts fish(-1). Anti-Ich antibody was detected using enzyme-linked immunosorbent assay in water samples taken from tanks containing immune fish after the water samples were concentrated 40-fold. The study suggests that immune fish cohabited with non-immune fish may protect non-immune fish against Ich infection. 相似文献
8.
Immunization of grouper, Epinephelus coioides, confers protection against a protozoan parasite, Cryptocaryon irritans 总被引：1，自引：0，他引：1
The present study aimed to determine whether protection is conferred by immunization of grouper, Epinephelus coioides, against a protozoan parasite, Cryptocaryon irritans. The immunization of E. coioides was carried out by a low level exposure of fish to live C. irritans theronts from predetermined number of tomonts and by an intraperitoneal injection of a vaccine consisting of formalin-killed C. irritans theronts.
Mucus titers detected by ELISA were significantly higher in fingerling and adult grouper subjected to the low level of exposure to C. irritans theronts at 3-week post-exposure compared to fish that had no previous exposure. In addition, significantly smaller tomonts were produced from adult grouper after three successive exposures than the tomonts produced after a single exposure to the parasite.
In the vaccine-immunization experiment, no mortality was monitored in fish that received high dose vaccine (100 μg/fish), while 40% cumulative mortality and 100% cumulative mortality were recorded in low dose group (10 μg/fish) and control group (PBS-injected), respectively. In the succeeding replicate, the vaccine-immunized group (high dose) had 37.5% cumulative mortality and 100% cumulative mortality for the control. In addition, a total of 1830 tomonts were collected at 5-day post-challenge from the control group while none from the vaccine-immunized group. Significantly fewer trophonts and tomonts were enumerated at 5-day and 7-day post-challenge, respectively, in the vaccine-immunized group than the control.
Results suggest that a protective immunity has been conferred on the immunized grouper as indicated by high antibody titers in the mucus of C. irritans-exposed fish and higher survival and fewer parasites in vaccine-immunized fish than the control groups. The conferred immunity played a major role in preventing or limiting the adhesion, invasion, and development of C. irritans theronts on the skin of the immunized grouper. 相似文献
9.
人工感染的刺激隐核虫各期虫体的超微结构 总被引：4，自引：2，他引：2
从天然感染的卵圆鲳鲹（Trachiruotus blochii）分离到1株刺激隐核虫（Cryptocaryon irritans）,再经人工感染的方法收集各期虫体,制成电镜样品,对虫体进行超微结构研究。刺激隐核虫质膜的基本结构与淡水的多子小瓜虫的质膜相似,分为3层;外限制膜、外胞膜和内胞膜。刺激隐核虫的质膜小泡内充满大量电子致密物质（EDM）。幼虫、幼体和滋养体均具有复杂的口器,由胞咽、口肋、双动基体口纤毛和线带等组成,但不具备膜口类纤毛虫所具有的独特的细胞器：Lieberkuhn氏器。单动基体的体纤毛存在于幼虫、幼体和滋养体,但在包囊期,体纤毛和口器消失。各期虫体的胞质中具有线粒体、高尔基体和脂肪体等细胞器,有的阶段具有粘液囊、伸缩泡、食物泡、共生细菌等。粘液囊在大小、形态和分布上与多子小瓜虫的不同。文中分析了刺激隐核虫在形态上与多子小瓜虫的诸多差异,认为刺激隐核虫的分类更适合归于原口类（Promotome）,而不是膜口类（Ophryoglenina）。 相似文献
10.
This study compared the susceptibility of three blue catfish strains (D&B, USDA 101 and USDA 102) to the parasite Ichthyophthirius multifiliis (Ich). In Trial I, a cohabitation study (all strains stocked communally) was conducted and fish were exposed to theronts at 0, 200, 1000, 5000 or 25 000 theronts fish?1, respectively. All fish died when exposed to theronts at 5000 or 25 000 theronts fish?1. When exposed to 1000 theronts fish?1, USDA 102 strain of blue catfish showed significantly lower mortality (78.5%) compared to USDA 101 and D&B strains (92.7% and 100%). In Trial II, the same three strains of blue fish were evaluated for their susceptibility to Ich with strains challenged in separate tanks by adding Ich theronts at 0, 200 and 1000 theronts fish?1, respectively. All D&B and USDA 101 blue catfish died; however, 42.3% of USDA 102 strain survived the infection when exposed to 1000 theronts per fish. The results indicate that there are differences among strains of blue catfish for susceptibility to Ich, and these differences will be useful in the development of improved catfish germplasm for commercial aquaculture. 相似文献
11.
研究从肉桂中分离纯化出具有抑杀多子小瓜虫活性的化合物。以乙醇为提取剂,用索氏超声提取法从肉桂中提取浸膏,再用石油醚、乙酸乙酯、甲醇为萃取剂,萃取不同有效组分,以不同浓度分别进行杀灭离体多子小瓜虫实验,发现石油醚萃取物的杀虫效果最优。然后对石油醚萃取物采用硅胶层析柱和制备型高效液相色谱进行分离纯化,利用质谱和核磁波谱分析,最终鉴定其杀虫活性成分为肉桂醛;将肉桂醛溶于二甲基亚砜并用二倍梯度稀释法配成不同浓度的药液测试其对离体小瓜虫的杀灭活性。结果表明,100%杀灭滋养体和感染性幼虫的剂量分别为50和8 mg/L,半数有效浓度分别为13.9和1.8 mg/L;使用剂量在50 mg/L可完全抑制小瓜虫包囊孵化。 相似文献
12.
Two in vitro methods for screening potential parasiticides against Ichthyophthirius multifiliis using Tetrahymena thermophila 
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下载免费PDF全文 Ichthyophthirius multifiliis (Ich) is a ciliate parasite that infects many species of freshwater fishes worldwide and causes heavy economic losses in aquaculture. Currently, parasiticides for controlling this parasite are limited, and few pond‐practical chemical therapies exist. Hence, the search for new parasiticides is urgently needed. One challenge confronting the screening of potential parasiticides is the difficulty in raising enough parasite for efficacy testing as Ich is an obligate parasite. This study used species of Tetrahymena, Ich‐related and cultivable ciliate protozoa, to evaluate two in vitro methods to test parasiticides. Plate counting and MTS assays (CellTiter 96® AQueous Non‐Radioactive Cell Proliferation Assay) were used to compare lethal concentrations or median lethal concentrations (LC50) of copper sulphate, formalin and malachite green between T. thermophila and Ich theronts or between T. thermophila and Ich tomonts. The parasiticides that killed T. thermophila have been demonstrated to kill theronts or tomonts. These in vitro methods using T. thermophila can be used to screen novel parasiticides against Ich. 相似文献
13.
Stuart J Rowland Charlie Mifsud Mark Nixon Philip Read Matthew Landos 《Aquaculture Research》2008,40(1):44-54
Infestations of the protozoan parasite, Ichthyophthirius multifiliis, cause the serious disease ichthyophthiriosis in freshwater fish throughout the world. Formalin is a recommended treatment for ichthyophthiriosis in the Australian fish silver perch (Bidyanus bidyanus Mitchell), but the disease is difficult to control in ponds, particularly at low water temperatures. Experiments were carried out to develop an improved treatment regime for formalin and to evaluate copper as a therapeutant. Silver perch fingerlings infested with I. multifiliis were stocked into 55 L aquaria at temperatures of 14.8–17.6 °C and alkalinities of 70–110 mg L?1. Formalin (34–38% formaldehyde) or copper (24.5% copper sulphate) were added to the aquaria and then monitored and readjusted to nominal concentrations daily. A concentration of 30 mg L?1 formalin controlled ichthyophthiriosis, but fish treated with 20 mg L?1 remained infested with theronts and trophonts on day 17; survival at both concentrations was 100%. A concentration of 10 mg L?1 formalin did not control ichthyophthiriosis and all fish were dead from the infestation by day 17. Fish treated with 0.1 or 0.2 mg L?1 copper were free of theronts and trophonts by days 17 and 14, respectively, and survival was 100%. Survival at 0.05 mg L?1 copper was 100%, but fish remained infested. At 0.25 mg L?1 copper, survival was 82.5% and there were no theronts or trophonts on gill and skin tissues of fingerlings by day 14. There was total mortality of fish treated with 0.5 or 1.0 mg L?1 copper suggesting these concentrations are toxic to silver perch. All fish in infested‐control treatments died. In earthen ponds containing silver perch, 0.2 mg L?1 copper was depleted to below 0.1 mg L?1 within 24 h, and concentrations of 25–38 mg L?1 formalin were depleted to below 15 mg L?1 within 48 h. Treatment regimes involving daily applications of formalin or copper controlled ichthyophthiriosis in silver perch in earthen ponds at costs of $US466.37 and $US65.58 hectare?1 day?1 respectively. This study has developed a new formalin‐treatment regime for the control of ichthyophthiriosis, and demonstrated that copper sulphate is a potential therapeutant for this serious disease of silver perch. 相似文献
14.
Cutaneous antibodies in excised skin from channel catfish, Ictalurus punctatus Rafinesque, immune to Ichthyophthirius multifiliis 总被引：3，自引：0，他引：3
This study determined whether cutaneous antibodies were present in the excised skin of channel catfish, Ictalurus punctatus Rafinesque, immune to Ichthyophthirius multifiliis Fouquet (Ich). Theronts were immobilized on or near the excised skin from immune fish. The survival of immobilized theronts was significantly reduced after exposure for 8 h to the culture of excised skin from immune fish. Culture fluids from excised skin of immune fish immobilized theronts with a peak in the immobilization titre at 24 h post-exposure. Immobility of theronts in the culture fluid from immune skin was removed after immunoabsorption with theronts. Indirect immunofluorescent staining of theronts treated with culture fluid from excised skin of immune fish revealed strong and uniform fluorescence on the cilia and cell surface of theronts. Western blot analysis of the culture fluid from immune fish revealed a 70-kDa band which corresponded to the molecular weight of catfish immunoglobulin heavy chain. The results of this study show that cutaneous antibodies to Ich theronts were present in and released from the excised skin from fish immune to Ich. Immobilization and killing of the theronts are two characteristics of the antibody response that appear to prevent the successful invasion of theronts into excised skin. 相似文献
15.
Abstract. Cryptocaryon irritans (Ciliophora), isolated from the reef fish, Grammistes sexlineatus Thumberg, was established as primary infections in mullet, Chelon labrosus (Risso). Only a small percentage (<22%) of exposed theronts established infection under controlled conditions. This is discussed in relation to the probability of host parasite contact and susceptibility. There was no evidence of density-dependent or intra-specific competition in trophont establishment, a strong linear relationship being found between the levels of exposure and infection. Infection intensity was assessed in relation to host survival, indicating a 90% probability of host death following levels of >200 trophonts per gram of host. A close temporal association between host death and trophont exit was found, possibly as a result of epidermal disruption leading to dysfunction of osmoregulatory and respiratory systems. 相似文献
16.
应用伴刀豆凝集素A、麦胚凝集素、大豆凝集素和荆豆凝集素Ⅰ,检测寄生于金鱼皮肤、鳃和鳍上的多子小瓜虫滋养体糖蛋白残基的种类和分布。研究结果发现,伴刀豆凝集素A和麦胚凝集素免疫阳性染色在金鱼皮肤、鳃和鳍寄生的滋养体上均有分布,麦胚凝集素免疫阳性染色强于伴刀豆凝集素A,未见有大豆凝集素和荆豆凝集素Ⅰ免疫阳性染色。鳃上寄生的滋养体伴刀豆凝集素A免疫阳性染色最强,皮肤次之,鳍最弱。鳍上寄生的滋养体麦胚凝集素免疫阳性染色最强,皮肤次之,鳃最弱。研究结果表明,滋养体有单糖D-甘露糖和D-葡萄糖,以及氨基衍生物乙酰氨基葡萄糖。寄生于鳃上的滋养体D-甘露糖和D-葡萄糖可能较多,寄生在鳍上的滋养体乙酰氨基葡萄糖可能较多。 相似文献
17.
Abstract. Juvenile carp, Cyprinus carpio L., were immunized against Ichthyophthirius multifiliis following controlled exposure to the infective theront stage. On challenge, with a potentially lethal dose of theronts, all immunized fish survived, in contrast to 100% mortality in non-immunized fish. Fourteen days following exposure to the challenge infection, immune and non-immune fish were injected intraperitoneally with either triamcinolone acetonide or hydrocortisone 21-hemisuccinate (cortisol) at doses of 100 μg or 10 μg/g body weight. Controls, including immunized and non-immunized fish, were injected with saline or left untreated. Six days following corticosteroid administration, fish were exposed to challenge infections of I multifiliis. All fish treated with corticosteroid developed heavy infections with up to 100% mortality. Repeat experiments gave comparable results. Serum antibody levels recorded in similarly treated fish at intervals of 12 h and/or 1 week following corticosteroid administration were found to be relatively unaffected. The results are discussed in relation to the immune response to I multifiliis . 相似文献
18.
Abstract. The host-parasite relationship between O-group carp and the ciliatc Ichthyophthirius multifiliis Fouquet was investigated, with the specific aim of characterizing the fate of parasites encountering immunized fish. Carp were immunized by repeated controlled infections; immunized fish and control fish naive to I. multifiliis were then infected in the caudal fin epidermis by a single controlled exposure to theronts, which were applied in a droplet suspension to the tail surface. The number of parasites present within the caudal fin was monitored over a subsequent 5-day period by means of in situ parasite mapping. Results indicated that, contrary to previous reports, theronts penetrated the skin of immunized fish in numbers comparable to those of fish receiving a primary infection. However, the majority of parasites which penetrated immune skin did not complete normal development; 79% of the parasites which had initially penetrated the immune skin were not relocated within 2h of exposure, and since no parasite material was detected at penetration sites, it was concluded that these parasites had prematurely exited the skin rather than been killed in situ. Subsequently, these sites became populated by leucocytes, predominantly macrophages, and the infiltrations continued for up to 5 days after the initial exposure. In contrast, at sites where mature trophonts had exited the skin of fish following a primary infection, more diffuse leucocytic infiltrations were recorded, and these were predominated by neutrophils. Differences in the response to parasite exit from immunized and previously unexposed control fish skin are discussed, with particular reference to the mode of protection and the fate of parasites encountering immune fish. 相似文献
19.
Luciano de O. Garcia Alexssandro G. Becker Mauro A. Cunha Bernardo Baldisserotto Carlos E. Copatti Daiani Kochhann 《Journal of the World Aquaculture Society》2011,42(3):399-405
The aim of this study is to determine the effect of (1) different pH levels (5, 6, 7, 8, and 9) with water hardness 20 mg/L CaCO3 and (2) pH 5 and 7 with varying water hardnesses (20, 60, and 120 mg/L CaCO3) on the intensity of infection by Ichthyophthirius multifiliis in fingerlings of the silver catfish, Rhamdia quelen. In Experiment 1, the lowest and highest mortality rates were observed in fingerlings exposed to pH 5 and 9, respectively; in Experiment 2, fish kept at pH 5 and 7 with hardness 20 mg/L CaCO3 showed significantly lowest and highest cumulative mortality, respectively, than those maintained in other conditions. The lowest intensity of trophonts/fingerling was observed at pH 5 and hardness 20 mg/L CaCO3 in both experiments. We conclude that infection by I. multifiliis is less severe in silver catfish maintained at pH 5 and hardness 20 mg/L CaCO3. High water hardness led to an increased intensity of trophonts and decreased survival in silver catfish kept at pH 5, but decreased intensity of trophonts and improved survival when the fish were kept at pH 7. 相似文献
20.
Rainbow trout (Oncorhynchus mykiss) immune response towards a recombinant vaccine targeting the parasitic ciliate Ichthyophthirius multifiliis 下载免费PDF全文
下载免费PDF全文 L von Gersdorff Jørgensen P W Kania K J Rasmussen A H Mattsson J Schmidt A Al‐Jubury A Sander A Salanti K Buchmann 《Journal of fish diseases》2017,40(12):1815-1821
The protective effect in rainbow trout (Oncorhynchus mykiss) of an experimental subunit vaccine targeting antigens in the parasite Ichthyophthirius multifiliis has been evaluated and compared to effects elicited by a classical parasite homogenate vaccine. Three recombinant parasite proteins (two produced in E. coli and one in insect cells) were combined and injected i.p., and subsequently, protection and antibody responses were analysed. Both the experimental and the benchmark vaccine induced partial but significant protection against I. multifiliis when compared to control fish. Specific antibody responses of vaccinated trout (subunit vaccine) were raised against one neurohypophysial n‐terminal domain protein #10 of three recombinant proteins, whereas the benchmark vaccine group showed specific antibody production against all three recombinant proteins. The immunogenic parasite protein #10 may be a potential vaccine candidate supplementing the protective I‐antigen in future vaccine trials. 相似文献