肝片形明虫 长菲策吸虫及日本血吸虫DNA的多态性检测

本试验用随机扩增DNA多态性技术对肝片形吸虫、长菲策吸虫和日本血吸虫虫体总DNA的多态性进行检测，结果筛选出三条具有种鉴别意义的RAPD谱带。这些特征性条带可望标记成探针用于粪便学检查中虫卵的鉴定。     

国产三氯苯咪唑驱除山羊肝片形吸虫效果试验

以国产三氯苯咪唑对自然感染肝片形吸虫的山羊进行了驱虫试验，并以硝氯酚为药物对照。结果表明，三氯本咪唑5mg/kg体重的剂量对肝片形吸虫成虫和童虫的驱虫率分别为99.3%和92.9%，驱净率为75％；三氯苯咪唑10mg/kg体重的剂量对肝片形吸虫成虫和童虫的驱虫率均为100％，驱净率为100％；硝氯酚5mg/kg体重剂量对肝片形吸虫成虫驱虫率为100％，但对童虫的仅为74.3%，而驱净率仅为60％。在整个试验期间试验羊均无不良反应。     

Wild fallow deer (Dama dama) as definitive hosts of Fasciola hepatica (liver fluke) in alpine New South Wales

To determine the extent to which wild deer are contributing in the transmission of Fasciola hepatica (liver fluke) livers from deer shot by hunters, farmers undertaking population control on their farms and vertebrate pest controllers were collected and frozen. The livers were later thawed, sliced and examined for the presence of adult flukes or evidence of past infection. Livers from 19 deer were examined (18 fallow [Dama dama] and one sambar [Rusa unicolor]). Seventeen of the fallow deer were animals collected on farms near Jindabyne, New South Wales. The remaining fallow deer was collected in the Australian Capital Territory and one sambar deer was collected in north-eastern Victoria. Nine of the 17 deer (53%) from the Jindabyne area were either infected with Fasciola hepatica (liver fluke) or had thickened bile ducts indicating past infection. Infection levels in the infected animals varied widely from 3 liver fluke to over 50 per liver. No sign of infection was present in the deer from the Australian Capital Territory or Victoria. Fallow deer are wide-spread in the Jindabyne area and their population is increasing. It is likely their contribution to the maintenance and distribution of F. hepatica to livestock in the Jindabyne area, and in other livestock rearing areas of south-eastern Australia, is important and increasing.     

肝片吸虫Fh8明显增强STEC的Stx1可溶性表达及Stx1单克隆抗体制备

志贺毒素1(Shiga toxin 1,Stx1),系五聚体蛋白,是产志贺毒素性大肠杆菌(Shiga Toxin-producing Escherichia coli,STEC)主要的毒素因子,但Stx1体外极不易可溶性表达,旨在克隆和表达志贺毒素1(Shiga toxin 1,Stx1)A亚基,体外获得可溶性表达的Stx1,以研制单克隆抗体。生物信息学软件分析Stx1A亚基氨基酸序列,Stx1A1亚基N端为信号肽段,其C端高疏水性和低免疫原性。PCR扩增stx1A亚基73~759的687个核苷酸,与肝片吸虫Fh8基因串联,克隆到低温表达载体p ColdⅠ以构建重组菌,诱导表达重组毒素His-Fh8-Stx1A,SDS-PAGE分析蛋白表达形式。重组毒素His-Fh8-Stx1A免疫Balb/c小鼠,Sp2/0细胞融合筛选、制备阳性杂交瘤和单克隆抗体。PCR扩增Fh8和stx1a亚基并构建重组质粒p ColdⅠ-His-Fh8-stx1,重组蛋白在原核细胞中得到高效表达,且以可溶性形式存在于菌体胞浆中。以重组His-Fh8-Stx1A为免疫原,成功制备3株能稳定传代并分泌Stx1的单克隆抗体(Mc Ab)的杂交瘤细胞株,取其中1株成功制备高ELISA效价的腹水。Western Blot显示,纯化的单克隆抗体可与重组免疫原His-Stx1A和天然志贺毒素1发生特异性反应。本试验成功可溶性表达志贺毒素1A亚基,并获得多株单克隆抗体,为研制用于检测STEC的夹心ELISA和胶体金试纸条奠定理论基础。     

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、病理损害等方面确实存在差别。     

斑点杂交试验检测小土窝螺的肝片吸虫感染

用斑点杂交试验检测苏、皖７县市肝片吸虫中间宿主小土窝螺（Ｇａｌｂａｐｅｒｖｉａ）的感染情况,共检测小土窝螺７７７个,阳性３３个,阳性率为４．２５％,其中江苏省小土窝螺的阳性率为４．３３％,安徽省小土窝螺的阳性率是４．１１％,结果表明本地水牛肝片吸虫感染率与小土窝螺阳性率呈正相关趋势,斑点杂交试验检测中间宿主小土窝螺可预测牛羊感染肝片吸虫的严重程度,是流行病学调查中值得采用的新技术。     

水牛慢性感染肝片吸虫后血液免疫功能指标及激素水平的动态变化

将８头经粪便检查和Ｄｏｔ－ＥＬＩＳＡ检测确认无肝片吸虫感染的雄性去势水牛随机分成感染组（ｎ＝５）和对照组（ｎ＝３）。感染组每天每头经口感染６０个囊蚴,连续２０ｄ。结果表明：水牛慢性感染肝片吸虫后,红细胞ＣＲ１花环率从感染后第２周即显著降低,而红细胞免疫复合物花环率则显著升高;白细胞数的总体水平在１９周前高于对照组,其中嗜酸性粒细胞显著增加,而淋巴细胞则有所下降;在淋巴细胞中可见Ｔ细胞比例显著下降,Ｂ细胞比例显著升高,并引起血清白细胞介素－２水平的降低和抗肝片吸虫的ＩｇＧ含量的显著升高。激素变化主要表现为皮质醇水平在感染初期升高,胰岛素在高于对照组的水平上波动,甲状腺激素Ｔ３、Ｔ４水平未见与对照组有明显差异。提示水牛在慢性感染肝片吸虫后,红细胞免疫功能下降,机体主要依靠嗜酸性粒细胞增加和产生特异性的ＩｇＧ抗感染,某些内分泌激素可能参与抗感染的调节机制。     

急性感染肝片吸虫水牛血中几种花生四烯酸代谢物及激素动态变化

选择12头健康、2～3岁、体重300～400kg雄性去势水牛，粪便检查和Dot—ELISA检测确认无肝片吸虫感染，随机分成感染组(n=9)和对照组(n=3)。感染组每头经口一次性感染1600个肝片吸虫囊蚴。研究了水牛急性感染肝片吸虫后血中几种花生四烯酸代谢物及激素动态变化。结果表明：水牛在急性感染肝片吸虫后整个实验期里没有明显的临床症状，具有较大的耐受力和抵抗力；水牛感染后，PGE2在16周前高于或明显高于对照组，以后两组相近；6—keto—PGF1α在整个实验期感染组与对照组无明显差异；TXB2在第1—10周低于或明显低于对照组。血浆Cort在第4—10周高于或明显高于对照组；T4在第4—22周总体水平高于或显著高于对照组；Ins和T3在整个实验期两组比较未见明显差异性变化。结果提示：水牛在急性感染肝片吸虫后，血中一些花生四烯酸代谢物变化明显，参与病理生理发生发展过程。     

Study on Blood Cell Immune Response in Water Buffaloes Infected Acutely with F. hepatica

Action mechanism of blood cell immune response in water buffaloes against acute infection with F. Hepatica was studied. The results showed that after water buffaloes were infected, the total levels of WBC surpassed control group during whole infection period; Eosinophiles (%) of DC were higher than control group at the 2nd week until 19th week, and then dropped and was close to control group; Neutrophiles(%)was low or significantly lower than control group within the 5 - 16th weeks; The total levels of lymphocytes (%) was lower than control group during the whole infection period; T-lymphocytes (%) dropped significantly, but B-lymphocytes(%) had opposite changes from the first week of infection, and they were close to the control group after 11 weeks; RBC-CR1 and RBC-IC rosette rates dropped and rose during 2 - 16 and 2- 18 weeks, respectively, and then approached the same between both groups. It was suggested that the violent changes of specific and nonspecific immune responses in water buffaloes with acute F. hepatica infection are related with the mechanism against infection with F. hepatica together.