两种片形吸虫感染家兔的试验比较

用大片形吸虫和肝片形吸虫感染家兔以便选择大片形吸虫对动物的最佳感染量，及明确号肝片形吸虫和大片形吸虫的生物学和对动物宿主的致病力的差别。结果显示肝片形吸虫虫体在兔体内发育成熟的时间早于大片形吸虫．感染成活率更高，对动物的病理损害明显比感染大片形吸虫兔的病变要轻。本试验证实这两种片形吸虫除了形态学的差异外，在对动物致病力、病理损害等万面确实存在差别。     

两种片形吸虫感染山羊的对比试验

片形吸虫病是在全球范围广泛流行，并对人有一定危害的寄生虫病。在大部分地区该病病原为肝片形吸虫（Fasciola hepatica），非洲、亚洲的热带地区是大片形吸虫（F．gigantica）。据本地的资料和以往的研究显示，广西主要是大片形吸虫。由于国内外对肝片形吸虫的研究较多，对大片形吸虫的研究较少，使得国内一些研究未能注意到这两个种的虫在对动物的致病性及其所引起的免疫反应等方面的差别。     

山区半山区羊肝片吸虫病感染情况调查与分析

肝片(形)吸虫病又叫肝蛭病,是由肝片吸虫和大片吸虫寄生在羊的肝脏胆管中引起的疾病.肝片吸虫病是牛、羊、骆驼的主要寄生虫病之一,它的病原体属片形科片形属的肝片形吸虫和大片形吸虫.     

有关水牛感染大片吸虫几点值得注意的问题

片形吸虫(Fasciola spp.)是一类寄生于反刍动物(水牛、奶牛和羊等)肝脏胆管的寄生蠕虫.片形吸虫有两个种(图1),分别为肝片吸虫(F.hepatica,分布于中国北方、欧洲等温带地区)和大片吸虫(F.gigantica,分布于中国南方、南亚等热带、亚热带地区).在我区,感染水牛的片形吸虫是大片吸虫,同时奶牛和山羊也常被这一寄生虫感染.     

肝片形吸虫与巨片形吸虫的DNA和氨基酸含量的分析

本文对肝片形吸虫和巨片形吸虫进行了组织化学探讨。结果表明：肝片形吸虫和巨片形吸虫的ＤＮＡ含量不同，二者比值为２：３，且所含１７种氨基酸种类相同，含量却不相同，某些氨基酸含量差别很大。     

德宏州山区羊肝片吸虫病流行规律及诊治

羊肝片吸虫病称为肝蛭病，是由片形科、片形属的肝片形吸虫（Fasciola hepatica）或大片形吸虫（Fasciola gigantica）引起，据1992年疫病调查在德宏州主要是肝片形吸虫。成虫寄生于牛、羊等多种动物的肝脏胆管内。幼虫在肝实质内移行，通过胆管，引起肝组织的损伤和大量出血；由于成虫阻塞胆道，可引起胆汁停滞、积贮，使局部实质病变；血液出现胆红素，甚至发生黄疽等症状。本病对羊危害极大，尤其对羔羊危害更为剧烈。     

波尔山羊常见寄生虫病防治技术

一、片形吸虫病 片形吸虫病是波尔山羊最主要的寄生虫病之一。由肝片形吸虫和大片形吸虫寄生于肝脏胆管所致。该病分布于全世界．我国遍布各地。主要危害羊、牛．人也可感染。感染山羊呈急性或慢性肝炎和胆管炎．贫血．并伴有全身性中毒现象和营养障碍．危害相当严重．尤其对幼畜可造成大批死亡。     

黄牛源Fh/Fg杂合型片形吸虫的鉴定

为弄清黄牛感染的片形吸虫种类,首先对来自河南济源市一肉牛屠宰场黄牛肝脏上的片形吸虫进行形态学观察,然后基于核糖体ITS1、ITS2区域和线粒体nad1、cox1基因序列进行分子鉴定。ITS1和ITS2序列分析结果显示,济源黄牛源片形吸虫分离株JY003和JY004为Fh/Fg杂合型片形吸虫。基于nad1和cox1基因序列,JY003和JY004与大片形吸虫的相似性高于肝片形吸虫,其中nad1序列与大片形吸虫中国云南、日本和韩国分离株的相似性高达100%。在基于nad1和cox1基因的进化树上,分离株均与大片形吸虫参考株处于同一分支。结果表明,首次从河南黄牛体内鉴定出Fh/Fg杂合型片形吸虫,为动物和人的片形吸虫病防控提供重要的基础数据。     

分子分类结合形态学观察鉴定重庆地区片形吸虫种类

目的明确重庆地区片形吸虫的种类,并为重庆地区片形吸虫的分类研究提供科学的参考依据。方法在对重庆地区黄牛、水牛肝脏上寄生的片形吸虫形态结构进行观察后,根据片形吸虫第一内转录间隔区(ITS-1)和第二内转录间隔区(ITS-2)基因设计特异性引物,运用多聚酶链式反应(PCR)技术,以法国肝片吸虫gDNA为对照,对所采样品gDNA用大片吸虫和肝片吸虫的ITS-1和ITS-2特异性引物进行扩增。结果形态学鉴定均为“不规则”片形吸虫,电泳结果显示均分别扩增出特异性ITS-1和ITS-2条带。结论综合形态学和PCR鉴定结果,初步认为重庆地区存在着大片吸虫和肝片吸虫的“中间型”。     

一例羊肝片形吸虫病的诊治报告

肝片形吸虫病是由肝片形吸虫及大片形吸虫引起，主要发生于反刍动物。其它哺乳动物和人也可感染，是危害养牛、养羊业的一种重要的寄生虫病。该病原是一类大型吸虫，肝片形吸虫长20～30mm，宽8～10mm，红褐色，呈扁平的叶片状，虫体肩部宽而明显；大片形吸虫长25～75mm，宽5～12mm，肩部不明显，后端钝圆。     

The serum glucose and beta-hydroxybutyrate levels in sheep with experimental Fasciola hepatica and Fasciola gigantica infection

The influence of Fasciola hepatica and Fasciola gigantica infection on serum glucose and beta-hydroxybutyrate (beta-HOB) in sheep was evaluated. This was done by setting up two groups of sheep. The first group (n=13) was split in two sub-groups, one experimentally infected with F. hepatica (n=9) and the other (n=4) as uninfected control. A second group consisting of a sub-group experimentally infected with F. gigantica (n=9) the other sub-group (n=6) left as uninfected control was also set up. The results of weight gain, parasitological and serum liver enzymes activity (glutamate dehydrogenase [GLDH] and gamma glutamyltransferase [gamma-GT]) used in monitoring the infection showed that all infected animals developed fasciolosis. It was observed that a reduction in serum glucose levels was significantly lower (p<0.05) in F. hepatica infected sheep than in uninfected control sheep starting from 5 weeks post-infection (wpi) to the end of the experiment. Similar reduction was recorded in F. gigantica infected sheep between 8 and 19 wpi. In contrast, serum beta-HOB levels were elevated in F. hepatica infected sheep between 6 and 16 wpi and in F. gigantica infected sheep between 7 and 15 wpi. It would appear from these serum glucose and beta-HOB levels that fasciolosis does lead to energy deficiency (low glucose) and ketosis (increased beta-HOB). The decrease in serum glucose and increase in serum beta-HOB levels in infected sheep may help in understanding the interaction between fasciolosis and nutritional status of infected ruminants especially in young growing animals.     

Innate and adaptive resistance of Indonesian Thin Tail sheep to liver fluke: a comparative analysis of Fasciola gigantica and Fasciola hepatica infection

In the current study, three independent trials directly compared Fasciola gigantica and Fasciola hepatica infection of ITT sheep. In all trials, F. hepatica infection resulted in higher worm burden recoveries and greater physiological damage to ITT sheep. Developmental differences of the two Fasciola species were also observed during the first twelve weeks of a primary infection, where the migration and growth of F. hepatica was more rapid than F. gigantica. Various immunological blood parameters were measured and indicated similar kinetics in the humoral and cellular responses during the time course of infection with each Fasciola species. In contrast to F. hepatica infection, we demonstrate an innate and adaptive comparative ability of ITT sheep to resist the early stages of infection with F. gigantica infection. Unraveling the mechanisms leading to this differential resistance may potentially lead to new methods for the control of fasciolosis and other human liver flukes.     

大片形吸虫幼虫的培育及其感染小鼠的研究

本试验旨在培育大片形吸虫囊蚴,着重研究大片形吸虫在中间宿主体内的发育过程和临床病理变化.人工培养和孵化大片形吸虫虫卵,用孵化出来的大片形吸虫毛蚴感染中间宿主小土蜗螺,收集大片形吸虫囊蚴,再用囊蚴感染试验小鼠.结果显示,囊蚴经口感染试验小鼠后1周即可在肝脏找到虫体,幼虫可在小鼠体内发育生存7～8周,随着时间的推移和感染囊蚴数量不同,可给小鼠肝脏造成不同程度的病变,甚至造成死亡.剖检小鼠可见肝脏质地脆,颜色发黄,脾脏肿大等严重病理变化.因此,可利用小鼠作为大片形吸虫幼虫感染的试验动物,进行片形吸虫病的早期诊断、免疫预防和治疗等方面的研究.     

Serum antibody isotype responses of Fasciola-infected sheep and cattle to excretory and secretory products of Fasciola species

This study investigated the immunoglobulin isotype responses of sheep and cattle chronically infected with Fasciola hepatica and Fasciola gigantica to adult F. hepatica excretory/secretory products (Fh-ES) or F. gigantica excretory/secretory products (Fg-ES), respectively. An antibody enzyme-linked immunosorbent assay (Ab-ELISA) was used to determine serum antibody (total Ig, IgG(1), IgM, IgG(2) and IgA) responses. At necropsy, the mean number of flukes recovered was lower in cattle than in sheep. All F. hepatica and F. gigantica infected sheep and cattle showed an increased total Ig levels from 3 to 4 weeks post-infection (wpi). Among isotypes IgG(1) was most dominant while IgM was the earliest (2 wpi) to be detected in both sheep and cattle infected with both F. hepatica and F. gigantica animals. IgG(2) response was early (2 wpi) in sheep infected by F. hepatica but there was no response in sheep infected with F. gigantica. There was a late and strong IgG(2) response in cattle infected with both flukes. The IgA isotype showed an early and a clear biphasic response in sheep with F. hepatica but was less pronounced in F. gigantica infected sheep. While IgA response to Fh-ES was noticed 5 wpi in F. hepatica infected cattle, it appeared much later (21 wpi) in those infected with F. gigantica. The dominance of IgG(1) isotype in infected sheep and cattle suggest an associated Th2 response. This early response to adult Fasciola spp. ES antigen suggests an early exposure to the antigen presumably through the cross-reacting ES products of juvenile flukes. There is clearly difference in IgG(2) isotype response in cattle (resistant) compared to sheep (susceptible). The late IgG(2) response in cattle may suggest late Th1 involvement in bovine cellular responses to adult Fh-ES/Fg-ES.     

Host responses during experimental infection with Fasciola gigantica or Fasciola hepatica in Merino sheep I. Comparative immunological and plasma biochemical changes during early infection

This study reports the early biochemical changes in plasma, comparative host-immune responses and parasite recovery data in Merino sheep during the first 10 weeks of infection with Fasciola gigantica and Fasciola hepatica. One group of sheep were uninfected, four groups of sheep received incremental challenge doses of F. gigantica metacercariae (50, 125, 225 and 400, respectively) and the sixth group was challenged with 250 F. hepatica metacercariae. At 10 weeks post infection (wpi), sheep challenged with F. hepatica showed the greatest fluke recovery (mean 119, range 84-166); a significantly higher biomass of parasites recovered (2.5-fold greater than the highest dose of F. gigantica); and a greater mean % parasite recovery (39.3%, range 27-55%) than any group challenged with F. gigantica. Within the groups dosed with F. gigantica a strong dose-dependent response was observed in both fluke recovery and fluke biomass with increasing dose of metacercariae. The mean % parasite recovery of F. gigantica infected groups 1-5 were 26, 23, 26 and 25%, respectively, suggesting a uniform viability of parasite establishment independent of infection dose. At 6 wpi, elevated levels of plasma GLDH were observed in the F. gigantica infected groups compared to the uninfected sheep (p<0.005) whereas the F. hepatica challenged group had four-fold higher levels of GLDH compared to the F. gigantica infected group (p<0.001). Elevated levels of GGT as an indicator of epithelial damage in the bile duct was only seen in the group challenged with F. hepatica at 10 wpi when it rose from below 100 IU/l to approximately 250 IU/l (p<0.0001) whereas no detectable increase in GGT was observed in any of the groups challenged with F. gigantica. The white blood cell response to F. hepatica infection was biphasic with the initial peak at 4 wpi and a second peak at 9 wpi, corresponding to the period of migration of juvenile fluke in the liver and the time when adult flukes are migrating into the bile duct, respectively. This biphasic response was also evident in the changes in the eosinophil counts and serum haemoglobin levels. There was a trend toward higher parasite-specific IgG2 titres in sheep infected with lower worm burdens, suggesting that higher F. gigantica or F. hepatica burdens suppress IgG2 responses. The findings of this study suggest that, in early infection in a permissive host, F. hepatica appears to be more pathogenic than F. gigantica because of its rapid increase in size and the speed of its progression through the migratory phases of its life cycle.     

Identification of the Egyptian species of Fasciola.

Reports on the species of Fasciola present in the Nile Delta, Egypt, appear controversial. Some authors reported the presence of both Fasciola gigantica and Fasciola hepatica, others reported F. gigantica only and mentioned that F. hepatica was found only in imported animals.This study was an attempt to identify the species of Fasciola flukes collected from locally bred animals. Morphologic, morphoanatomic, morphometric, and chemotaxonomic criteria of the fluke isolates were studied. Speciation based on morphologic and morphometric data was not decisive due to overlap in the values of most measurements. Morphoanatomic data proved the presence of both the species, and isoelectric focusing (IEF) of fluke soluble protein confirmed the presence of both F. gigantica and F. hepatica in Egypt.     

片形吸虫DNA随机扩增多态性分析

为区别从南京市江宁县采集的片形吸虫非典型形态虫体，应用随机扩增多态性DNA（RAPD）技术，对6株片形吸虫总DNA进行了扩增。结果，10条引物中有8条能产生扩增图谱，电泳图谱经聚类分析，与传统的分类结果一致，并表明来自江宁的片形吸虫既有形态典型的肝片形吸虫，也有形态不典型的大片形吸虫。     

Studies on the prevalence and laboratory transmission of fascioliasis in animals in the Kashmir Valley

In Kashmir, 85.1% of cattle, 51.3% of sheep and 14.8% of goats were found infected with Fasciola spp. The prevalence rate varied from 66.6 to 100.0%, 25.0 to 100% and nil to 66.0% in cattle, sheep and goats respectively in different months of the year. Fasciola gigantica was the predominant species in all animal species but sheep harboured both F. gigantica and F. hepatica. The prevalence of F. hepatica infection in sheep happens to be the first report from India. Lymnaea auricularia sensu stricto supported the development of F. gigantica under laboratory conditions. The incubation temperature affected the shedding of the cercariae. Snails maintained at 25-27 degrees C started cercarial shedding as early as day 20 post-infection (PI), whereas those maintained at 10-12 degrees C commenced it from day 64 PI. One out of three experimentally infected guinea pigs aged 1 month revealed adult flukes in the liver at necropsy on day 52 PI.     

Humoral and cellular immune responses to Fasciola gigantica experimental infection in buffaloes

Humoral and cellular immune responses to Fasciola gigantica experimental infection in buffaloes were studied. The results showed that 33.4+/-9.1% of the infection dose was recovered as adult flukes from infected animals at necropsy. Significant differences of weight gain between infected and non-infected buffaloes was observed at 4 MPI (months post-infection). Anti F. gigantica excretory-secretory products (FgESP)-IgG levels increased significantly from 3 WPI (weeks post-infection) and displayed a peak at 13 WPI. Western blot indicated that in FgESP six major bands of 11.5, 19.0, 23.4, 29.8, 47.5 and 53.2kDa were recognized by F. gigantica-infected buffaloes sera after 0 WPI. Eosinophil numbers increased significantly from 3 WPI in F. gigantica-infected buffaloes and displayed a peak at 8 WPI. Peripheral blood mononuclear cells (PBMC) proliferation induced by FgESP increased from 2 WPI with a peak at 5 WPI. IFNgamma secretion by FgESP-stimulated PBMC appeared early from 1 WPI with three peaks at 2, 5 and 8 WPI, respectively. IL-10 production was observed from 2 WPI with two peaks at 4 and 9 WPI, respectively. Our results suggested that buffaloes were highly susceptible to F. gigantica infection, and this susceptibility could be associated with the late and weak cellular immune response in the early phase of infection and the Th0-like response throughout the infection.