淮南地区禽畜体内寄生人兽共患吸虫的种类

目的 目的 了解安徽省淮南地区禽畜体内寄生人兽共患吸虫的种类, 为防治人兽共患吸虫病提供参考依据。方法 方法 从淮南市禽畜市场选购人兽共患吸虫的终宿主, 处死后取出内脏并解剖, 获取虫体, 制片鉴定, 同时检索整理有关淮南地 区禽畜体内寄生吸虫的文献。结果 结果 经分类、 鉴定和整理, 淮南地区禽畜体内寄生吸虫迄今共发现41种, 其中人兽共患吸 虫23种, 仅在禽畜体内寄生吸虫18种, 分属4目12科21属, 分别寄生于鸡、 鸭、 鹅、 猪、 黄牛、 水牛、 绵羊、 山羊和犬等9种终 宿主。结论 结论 淮南地区禽畜体内寄生人兽共患吸虫的种类较多, 引起人群人兽共患吸虫病传播与流行的危险较高, 应引 起高度重视。     

Immune dependence of schistosomicidal chemotherapy: an ultrastructural study of Schistosoma mansoni adult worms exposed to praziquantel and immune serum in vivo

This study examines the immune-dependence of praziquantel (PZQ) for the treatment of Schistosomiasis mansoni in mice. We have shown elsewhere from worm recovery data that the efficacy of PZQ is significantly enhanced when mice are treated concomitantly with antisera raised against antigens released from adult schistosomes, even though such antisera show no intrinsic helminthotoxic activity (Doenhoff et al. 1987, Doenhoff, Modha & Lambertucci 1988). Moreover, indirect immunofluorescence assays have shown that male worms exposed to the dual treatment regime in vivo bind antiserum to their dorsal surfaces in a pattern that seems to follow the outline of the dorsal tubercles. Scanning and transmission electron microscopy have now been used to further define the features of damage inflicted upon worms through exposure to antiserum alone, drug alone, or the two treatments in combination. Such investigations revealed that the antiserum induces a classical membrane repair process in worms of both sexes, but little other damage. PZQ causes the formation of spherical protuberances on the dorsal tubercles of male worms, while the dual treatment regime induces both kinds of damage in male schistosomes, but with much enhanced severity. The protuberances show evidence of explosion and some regions of the tegument become completely destroyed. Regions other than the dorsal surfaces of the male worms do not exhibit comparable trauma, and neither do the females. These data are discussed in relation to the known schistosomicidal activity of PZQ, the notion that male and female worms exhibit regional and sexual differences in susceptibility, documented evasive strategies of the parasite and the interdependence of immuno- and chemotherapy.     

Site potential for challenge attrition in mice, rats and guinea pigs vaccinated with irradiated cercariae of Schistosoma mansoni

The potential sites of attrition of a challenge population of schistosomes have been investigated in mice, rats and guinea pigs vaccinated with irradiated cercariae of Schistosoma mansoni, by the use of challenge regimens that permit sequential site elimination. Vaccinated mice showed significant immunity to a percutaneous cercarial challenge, but were only marginally resistant to an i.v. challenge with healthy lung stage worms. Vaccinated rats and guinea pigs differed from mice, in that they were able to mediate significant challenge attrition at post-skin sites. Healthy lung worms were subject to immune elimination by rats in the lungs, or perhaps en route to the liver, but not in the liver itself. In contrast, guinea pigs had the capacity to kill challenge lung worms injected into either the lungs or the liver. Interestingly, lung worms harvested by extended incubation were shown to be sub-optimal in terms of viability, since they were eliminated in significant numbers when injected i.v. into vaccinated mice. These data show that different hosts vaccinated in essentially the same manner differ in terms of their site potential for challenge attrition. It is emphasised however, that sites implicated by these experiments as having the capacity to mediate immune elimination are not necessarily the sites at which challenge attrition occurs under normal circumstances.     

Biochemical characterization and localization of Fasciola hepatica 26-28 kDa diagnostic coproantigen

We have previously reported the usefulness of a 26-28 kDa coproantigen of Fasciola hepatica for diagnosis of infection. In this study, the 26-28 kDa coproantigen was biochemically characterized with the aid of monoclonal antibodies (MoAb) in an effort to better understand the biology of the antigen. Differential staining of chromatographically-purified 26-28 kDa coproantigen on SDS-PAGE, under reducing and non-reducing conditions, indicated that the coproantigen was a monomeric, highly glycosylated glycoprotein. Alkaline treatment of the purified coproantigen resulted in an 8 kDa protein core which still contained the epitope recognized by the MoAb. No protease activity was associated with the 26-28 kDa coproantigen. The coproantigen could be cleaved by trypsin without altering the reactive epitope recognized by the MoAb, but was resistant to pepsin digestion. Further, the coproantigen was stable under several different storage conditions. Indirect immunofluorescence on tissue sections of adult flukes indicated that the coproantigen was present in gut cells and tegument. Taken together these results confirm the stability of the 26-28 kDa coproantigen and its usefulness in diagnostic tests for F. hepatica infections.     

Epidemiology of Opisthorchis viverrini in a rural district of southern Lao PDR

In Lao PDR, detailed investigations on Opisthorchis viverrini are scarce. The objective was to document epidemiological features of O. viverrini infections in a highly endemic district. A random sample was selected (13 villages, 15 households/village, all household members aged >6 months). Clinical examinations, short interviews and stool examinations (Kato-Katz technique) were performed. Fish samples were dissected for the presence of metacercaria. In total, 814 persons were enrolled (median age 16 years, 51.5% women). The prevalence was 58.5%. Infection rates increased with age (from 20.0 to 85.5%; P<0.001). Intensity of infection and the habit of consuming insufficiently cooked fish also increased with age. Of the study participants, 75.2% reported cooking fish insufficiently. Of the 23 different species of cyprinoid fish consumed in the study villages, 20 species were infected. At the village level, the prevalence of raw fish consumption was strongly associated with the infection status of O. viverrini (r=0.76, P=0.003). At individual level, age, the consumption of insufficiently cooked fish, and the absence of sanitation were strongly associated. The disease associated with O. viverrini infection needs to be assessed in order to develop and conduct adequate interventions.     

附件棘隙吸虫与4种鱼源性吸虫混合感染的调查

目的 :调查福建棘隙吸虫等多种吸虫混合感染情况。方法 :采用改良加藤法或水洗过筛沉淀法粪检 ,对吸虫卵阳性人群和终宿主动物分别作驱虫与解剖观察 ,对鱼类宿主取鱼鳃和鱼肉等组织 ,镜检囊蚴。结果 :查出福建棘隙吸虫 ( Echinochasmus fujianensis)、华支睾吸虫 ( Clonorchissinensis)、日本棘隙吸虫 ( Echinochasmus japonicus)、钩棘单睾吸虫 ( H ap lorchis pumilio)和台湾棘带吸虫 ( Centrocestus taiwanense)等 5种 ;人群感染率为 4 .6% ( 81/ 1774 ) ,有 33.7%感染者同时感染 2种或 3种吸虫 ,第二中间宿主为麦穗鱼等 11种 ,感染率为 4 9.1% ( 169/ 34 4 ) ;不同吸虫囊蚴寄生鱼体部位不同 ;保虫宿主为狗、猫和 2种鼠类等 4种 ;混合感染率为 53.5% ( 2 3/ 4 3)。结论 :当地为兽主人次的鱼源性 5种吸虫混合感染区 ,人体自然感染钩棘单睾吸虫系首次报告。     

Immobilization of Schistosoma mansoni miracidia by activation of the alternate complement pathway at unusually high serum dilution

Free-swimming Schistosoma mansoni miracidia were immobilized by adding normal mammalian serum to the water. Miracidial immobilizing activity (MIA) was shown to result from activating the alternate pathway of complement (APC). MIA in normal sera was heat-sensitive and anibody independent; it was greatly reduced in factor B-depleted or C6-depleted, but not in C1-depleted, human serum. Addition of purified factor B to B-depleted serum totally restored MIA. Half-maximal MIA in normal human, rabbit, and guinea pig sera was detectable at final dilutions exceeding 1/100, 1/200, and 1/500, respectively, and normal rat serum was particularly potent, with MIA at dilutions exceeding 1/2000. Detection of APC activity at such high dilutions is quite extraordinary and attributed to the hypotonic conditions. We confirmed and extended previous findings that heat-inactivated infection sera also display MIA. Immobilizing activity in irradiated-cercarial vaccine rat serum cofractionated with rat IgG and anti-SWAP antibody activity. Antibody-dependent MIA titres were much lower than for APC-dependent MIA. Based upon light microscope and transmission EM studies, immobilization of miracidia by APC activation was attributed to severe tegumental damage. Miracidia within egg shells were insensitive to MIA.     

鄂西自治州肺吸虫病流行病学调查

本文报告了湖北鄂西自治州从1976—1985年对肺吸虫病流行病学进行了调查,人群皮试160491人,结果有39229人被感染,发病15972人,平均感染率为24.44％,患病率为9.95％,其中男性高于女性,5-19岁感染率构成高达92.71％,病例中有典型游走性包块、突眼、脑型者占14.21％,非典型患者占85.78％,患者有吃蟹史62.98％。蟹、螺平均感染率分别为49％、0.067％,保虫宿主感染率为27.88％,虫种为斯氏并殖吸虫。     

Monoclonal antibodies against Opisthorchis viverrini antigens

Summary Monoclonal antibodies (MoAb) were produced against somatic antigens of adult human liver fluke Opisthorchis viverrini. Earlier studies attached diagnostic potential to an 89–90 kD antigen present in both somatic extracts and in vitro culture supernatants as well as to the abundant 16–17 kD tegumental protein doublet. Mice made excellent immune responses to low dose somatic extract adsorbed onto nitrocellulose or to the 80–95 kD region of SDS gel Western blots. The antigen specificities of hybridomas reactive with somatic antigen by ELISA were determined by radioimmunoprecipitation or immunoblotting. Six MoAb reacted with the desired 16 kD tegumental protein. A 90 kD somatic protein was identified by 9 clones. By indirect immunofluorescence, monoclonals reactive with the 16 kD polypeptide identified the outermost surface of the tegument. The 90 kD antigen was associated with all major muscle systems, most strikingly the crossed subtegumental layers, oral and ventral suckers, pharynx and a thin layer surrounding caeca. The biochemical identity of this muscle-associated antigen is unknown, but it is clearly distinct from the previously identified species-specific 89 kD exoantigen. The 16 kD tegumental protein shares epitopes with a number of related flukes. However, 2 MoAb which react with this protein show no crossreaction.