小瓜虫抑动抗原研究综述

<专刊>= <栏目>=研究论文 <图片>= <表格>= <连载>= <来源>= <中图分类号>=S942.2 <主题分类>= <行业分类>= <本刊专题>= <本刊编号>=1005-8737-(2007)07-123-06 <基金项目>=福建省自然科学基金项目(B0610021；2006J0067). <注释>= <     

重组多子小瓜虫抑动抗原ISCOMs制备

提取表达于四膜虫(Tetrahymena thermophila)细胞膜表面的多子小瓜虫抑动抗原.通过Western Blotting证实重组多子小瓜虫抑动抗原约为35.7 kD,其免疫原性与多子小瓜虫抑动抗原相似.以Quil-A作为佐剂,采用离心、超声波和透析等方法制备小瓜虫抑动抗原免疫刺激复合物(Iag-ISCOMs).电镜观察可见Iag-ISCOMs经磷钨酸负染后呈直径30～40 nm的笼格状结构.免疫和攻毒试验证实Iag-ISCOMs对鳗鲡具有一定保护能力,攻毒后存活率达71.4％,对照组存活率为43.9％,结果表明,本实验成功制备了具有一定免疫原性的Iag-ISCOMs.     

简并PCR扩增小瓜虫抑动抗原基因的ORF

抑动蛋白是小瓜虫(Ichthyophthiriusmultifiliis)体表纤毛的主要构成部分,也是宿主免疫系统发挥抗虫免疫时的主要识别抗原。根据已经报道的3种抑动蛋白N端及C端保守的多肽片断,设计了一对简并引物P6/P7,以小瓜虫分离株IchFJ9的基因组为模板,成功扩增了抑动蛋白编码区(ORF)的全长基因序列。扩增的iagFJ9基因全长1398bp,编码466个氨基酸,包含18个非标准密码子TAA(Glu,Q)推导的氨基酸序列包含6个以CPXGT为起始的串联重复单位,具有抑动蛋白的特征性结构。同源比较分析显示,扩增的iagFJ9基因与已知的小瓜虫抑动蛋白基因IAG52A基因具有88%同源率。证实了iagFJ9是一个新发现的抑动蛋白基因,用简并PCR技术去发现小瓜虫抑动蛋白基因家族新基因是可行的。     

刺激隐核虫与多子小瓜虫免疫学特性比较研究综述

刺激隐核虫(Cryptocaryon irritans)与多子小瓜虫(Ichthyophthirius multifiliis)是影响渔业生产重要寄生虫,本文主要阐述了刺激隐核虫与多子小瓜虫种内和种间的免疫学相似性和差异性,及其两种寄生虫抑动抗原的免疫学特性以及克隆表达研究。为免疫学方法预防两种寄生虫病提供理论依据。     

匙吻鲟小瓜虫病的观察与防治

匙吻鲟Ｐｏｌｙｏｄｏｎｓｐａｔｈｕｌａ隶属于匙吻鲟科Ｐｏｌｙｏｄｏｎ ｔｉｄａｅ,主要分布于美洲北部,我国从1990年开始从美国引进。通过10多年的引进与推广,在受精卵孵化、仔鱼培育、苗种培育等方面取得一定的进展,不少地方已开展了人工养殖。但在匙吻鲟苗种培育过程中,有些地方发生了小瓜虫病,致使苗种大量死亡,造成严重损失。现将我们1998年和2000年进行的小瓜虫病的观察与防治总结如下。1　基本情况匙吻鲟苗种系从美国引进受精卵,在实验室内经孵化、仔幼鱼培育而成。养殖容器为长方形(90ｃｍ×50ｃｍ×70ｃｍ)和圆形(直径135ｃ…     

小瓜虫病

小瓜虫病——很多淡水鱼和海水鱼的一种侵袭性鱼病，在鱼池繁殖的小瓜虫，具有损害皮肤、鳍和鳃的特性。它们主要分布在欧洲、美洲和加拿大的养鱼场和孵化场。在天然水域中小瓜虫病流行极少出现，但是，几乎所有的淡水鱼都是小瓜虫病的病媒而引起小瓜虫病。     

小瓜虫病(Ichthyophthiriasis)防治新方法试验报告

本文报道采用0.0750ppm小瓜虫没1号治愈金鱼、鲤鱼小瓜虫病新方法,施药后48h在鱼体未找到活体 小瓜虫。小瓜虫没1号对金鱼的安全浓度为0.0999ppm。     

小瓜虫病

2008年农业部兽医局委托动物流行病学中组织专家编写动物疫病释义,为便于解读水生动物的疫病,本刊现将《一、二、三类动物疫病病种名录》中水生动物疫病种类的分类及各病的释义分期进行刊登。小瓜虫病,又称白点病,是由多子小瓜虫寄生于淡水鱼类体表和鳃引起的一种寄生病,以病鱼体表或鳃呈现小白点为特征。为我国的三类水生动物疫病。     

Molecular characteristics of an immobilization antigen gene of the fish-parasitic protozoan Ichthyophthirius multifiliis strain ARS-6

Ichthyophthirius multifiliis (Ich), a ciliated protozoan parasite of fish, expresses surface antigens (i-antigens), which react with host antibodies that render them immobile. The nucleotide sequence of an i-antigen gene of I. multifiliis strain ARS-6 was deduced. The predicted protein of 47 493 Da is comprised of 460 amino acids (aa's) arranged into five imperfect repeats with periodic cysteine residues with the structure: CX₍₁₉₎₂₀CX₂CX₁₆₋₂₇CX₂CX₂₀₍₂₁₎CX₃. The N-terminal aa's typify a signal peptide motif while a stretch of C-terminal aa's resemble a glycosyl–phosphatidyl–inositol (GPI)-anchor addition site. The degree of deduced i-antigen aa sequence identity of strain ARS-6 (GenBank accession # ACH87654 and # ACH95659) with other I. multifiliis i-antigen sequences present in GenBank ranges from 99% to 36% identity with 52 kDa i-antigens of I. multifiliis strain G5 (accession #s AAK94941 and AAK01661 respectively). Immunoblot analysis of i-antigens following exposure of I. multifiliis theronts to catfish anti- I. multifiliis immune serum did not show any appreciable alteration in i-antigen expression. The mechanism that regulates i-antigen expression in I. multifiliis remains a puzzling question.     

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 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.     

杀灭离体小瓜虫的药物试验

研究不同的药物及同一药物不同浓度对小瓜虫的成虫、幼虫、包囊的杀灭作用。 0 2～ 0 5mL/L甲醛、 2 %食盐水、 0 2～ 0 2 5mL/L冰乙酸、 0 2mL/L双氧水、辣椒老姜混合熬煮液、苦楝果熬煮液对离体小瓜虫均有明显的杀灭作用。而 1%食盐水、辣椒熬煮液、老姜熬煮液、苦楝树皮熬煮液、黄荆粗枝及细枝熬煮液、 0 7mg/L铜铁合剂对生活史中任何阶段小瓜虫均无杀灭效果。     

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, 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.     

Cell-mediated immune response of goldfish, Carassiusaurafus (L.), to Ichthyophthirius multifiliis

Goldfish, Carassius auratus (L.), were intraperitoneally injected with two doses of Ichthyophthirius multifiliis (each containing 2.3 × 10⁶ live tomites) in saline, 30 days apart. The control fish were injected with saline only. Two weeks after the last vaccination, fish of both groups were intradermally injected with 2.5 × 10⁵ live tomites for skin tests. The skin at the antigen-injected site of the vaccinated fish increased in thickness from 8 h onwards and reached a peak at 24 h. Histological study showed a heavy infiltration of mononuclear leucocytes at the antigen-injected site. In contrast, no such changes were encountered in control fish. The migration area of pronephros cells from the vaccinated fish was significantly inhibited, in vitro, compared to controls with the presence of antigens. These findings suggest that the tomite-vaccinated fish produced a cell-mediated immune response. However, vaccinated fish also exhibited significantly higher titres of immobilizing antibodies in their sera and mucus than the controls. Therefore, it is likely that both humoral and cell-mediated immune responses have to work closely together to eliminate the infectious tomites of I. multifiliis which succeed in penetrating the fish epithelial tissues.