广西2月龄内犊奶牛隐孢子虫感染情况调查

<正>自Tyzzer(1907)首次发现小鼠隐孢子虫(C.muris)以来,国内外学者对隐孢子虫病进行了大量研究,已在人、哺乳动物、禽类、爬行动物和鱼类等多种动物中发现15个种类的隐孢子虫感染[1-3],其中可感染牛的隐孢子虫种为安氏隐孢子虫(C.an-dersoni)、小球隐孢子虫(C.parvum)、牛隐孢子虫(C.bovis)、小鼠隐孢子虫(C.muris)、犬隐孢子虫(C.ca-     

国际上首次报道犊牛感染火鸡隐孢子虫

中国兽医信息网中国疾病预防控制中心寄生虫病预防与控制所重点实验室沈玉娟研究员与哈尔滨医科大学刘爱芹教授合作在《PLoSONE》杂志上发表文章,报告了我国黑龙江省哈尔滨、大庆、牡丹江和齐齐哈尔地区断奶前犊牛隐孢子虫感染调查情况：总感染率为47.68%（72/151）,分子鉴定为牛隐孢子虫47.22%（34/72）,安氏隐孢子虫36.11%（26/72）,赖氏隐孢子虫6.94%（5/72）,火鸡隐孢子虫6.94%（5/72）和微小隐孢子虫2.78%（2/72）。其中微小隐孢子虫、安氏隐孢子虫和火鸡隐孢子虫,均为人兽共患隐孢子虫虫种,具有潜在的公共卫生危害。亚型分型：微小隐孢子虫亚型为IIdA19G1,火鸡隐孢子虫亚型为IIIeA22G2R1。在我国犊牛自然感染火鸡隐孢子虫具有地域流行特点,系国内外首次报道。火鸡隐孢子虫主要感染禽类,也是继人隐孢子虫和微小隐孢子虫后,第三大能感染人的隐孢子虫虫种。而犊牛作为火鸡隐孢子虫的储存宿主,需要开展更多系统的实验感染研究来证实;同时应对人、动物进行进一步的分子流行病学研究,来阐明微小隐孢子虫和火鸡隐孢子虫等传播动力学关系。     

禽隐孢子虫病的诊断与防治

<正>隐孢子虫病是家禽、鸟类最常见的寄生虫病之一,隐孢子虫的宿主多达30余种,目前,隐孢子虫种已达20余种,寄生于禽类的隐孢子虫有3个虫种,即火鸡隐孢子虫(Cryptosporidiummeleagridis)、贝氏隐孢子虫(C.baileyi)和鸡隐孢子虫(C.galli)。我国发现的禽隐孢子虫有2种包括贝氏隐孢子虫(C.baileyi)和火鸡隐孢子虫,主要引起呼吸系统、消化系统疾病,导致产蛋率下降或鸡只死亡,当与其他传染病,免疫抑制性共同感染时,会造成更为严重的经济损失。     

印度西孟加拉奶牛隐孢子虫人畜共患传播的分子特性及评估

过去很少开展印度奶牛隐孢子虫遗传多样性和在人畜共患潜力方面的研究。为了评估奶牛作为人感染隐孢子虫传染源的重要性,从印度西孟加拉2个奶牛场采集180头奶牛和50位养殖工人的粪样,用PCR方法扩增隐孢子虫DNA序列,通过PCR-RFLP分析进行隐孢子虫18S rRNA基因分型。对本试验扩增的DNA序列和GenBank公布的相关序列进行系统发育分析。青年奶牛的隐孢子虫感染率高于成年奶牛的感染率,总感染率为11.7%。微细隐孢子虫、牛隐孢子虫等在牛上的发生率呈年龄相关。在1份小牛样品中检测到了猪隐孢子虫基因型DNA。养殖场工人感染了人隐孢子虫、微细隐孢子虫和新型牛隐孢子虫。试验结果表明,印度奶牛场存在人和奶牛之间传播隐孢子虫的潜在风险。     

一例禽隐孢子虫病的诊治

正禽隐孢子虫病是由隐孢子虫科隐孢子虫属的贝氏隐孢子虫、火鸡隐孢子虫寄生于家禽的呼吸系统、消化道、法氏囊和泄殖腔内所引起的一种原虫病。隐孢子虫病呈全球性分布,能使鸡、鸭、鹅等多种家禽致病,是仪次于球虫病的高发性原虫病。近年来,由于禽场的饲养管理水平不断提高,典型的禽隐孢子虫病病例在规模化禽场已很少     

隐孢子虫病检测技术研究进展

隐孢子虫是动物和人腹泻的重要病原,也是人类艾滋病患者的主要致死因素之一.当前,对隐孢子虫病的研究已成为全球寄生虫学研究领域的热点由,于迄今尚无治疗隐孢子虫病感染的特效药物,因此,快速、简便、准确地发现隐孢子虫是控制该病的关键.随着分子生物学技术的应用,隐孢子虫病的检测技术得到了极大的发展.笔者就近年来隐孢子虫病检测技术进行了简要综述.     

四种隐孢子虫半胱氨酸蛋白酶Cryptopain-1基因的克隆和序列分析

为克隆不同种隐孢子虫(Cryptosporidium spp.)的半胱氨酸蛋白酶Cryptopain-1基因,分析其核苷酸与编码氨基酸序列的变异情况,根据GenBank上公布的微小隐孢子虫(C.parvum)Cryptopain-1基因序列设计合成引物,用PCR技术从不同种隐孢子虫基因组DNA中扩增Cryptopain-1基因,并将其克隆至pZeroBack/blunt载体,阳性克隆经PCR鉴定正确后测序,与微小隐孢子虫Cryptopain-1基因进行序列同源性比对,并进行系统进化分析。结果显示,本研究成功从泰泽隐孢子虫(C.tyzzeri)、火鸡隐孢子虫(C.meleagridis)、兔隐孢子虫(C.cuniculus)基因组DNA中扩增出Cryptopain-1基因。与微小隐孢子虫Cryptopain-1基因比较,泰泽隐孢子虫、火鸡隐孢子虫、兔隐孢子虫Cryptopain-1基因核苷酸序列相似性分别为98.67%、94.53%、98.34%,演绎的氨基酸序列相似性分别为99.00%、96.51%、99.00%。研究结果为利用Cryptopain-1基因进行隐孢子虫的代谢、致病机理等研究奠定了基础。     

禽隐孢子虫病研究概况

禽隐孢子虫病是由火鸡隐孢子虫(Cryptosporidium meleagridis)和贝氏隐孢子虫(C、baileyi)引起的以消化道和呼吸道症状为主的禽类寄生原虫病。自1929年Tyzzer首次报道在鸡的盲肠上皮细胞上发现隐孢子虫以未,有关学者对禽隐孢子虫病的病原学、流行病学、临床病理学、诊断学等方面做了大量研究,取得了一定的成就。本文就禽隐孢子虫病的研究概况,作一综述。     

牛源隐孢子虫新疆南疆分离株巢式PCR鉴定

为了解新疆南疆牛隐孢子虫病的感染情况,从而为该病的防控提供理论依据,以新疆南疆某牛场牛粪中的隐孢子虫卵囊DNA为模板,根据隐孢子虫18S rRNA序列设计引物,采用巢式PCR方法鉴定了自然感染的新疆南疆牛源隐孢子虫,并对扩增出的目的片段进行了测序、同源性分析,并运用MEGA 5.0软件构建系统发育进化树。结果表明:检测材料能够扩增出目的片段;新疆南疆牛源隐孢子虫分离株的18S rRNA与广州微小隐孢子虫的同源性达100%,种系发育亲缘关系最近,处于同一分支,与宁夏、河南、黑龙江等地微小隐孢子虫的同源性达99%。说明新疆南疆牛源隐孢子虫分离株在种属上为微小隐孢子虫。     

羊隐孢子虫病的防控

正隐孢子虫病是一种世界性的人兽共患寄生虫病,可引起哺乳动物产生严重腹泻,并伴有厌食、生长停滞等症状,严重者可导致死亡。1病原及生活史在我国,寄生于羊体内的隐孢子虫有2种,分别为小鼠隐孢子虫和小隐孢子虫,分类上均属于隐孢子虫科隐孢子虫属。前者寄生于胃黏膜上皮细胞,后者寄生于小肠黏膜上皮细胞。隐孢子虫为单宿主生活     

The passive protection of lambs against Clostridium perfringens type D with semi-purified hyperimmune serum

Weaned lambs, having a detectable level of maternal antibodies (1-2 units/ml) against C. perfringens type D, showed protective antitoxin levels lasting for 29 days after receiving a single parenteral dose of 200 units/kg hyperimmune serum. Lambs, having no maternal antibodies (less than 0,07 units/ml) to C. perfringens type D but receiving the same dose of hyperimmune serum, maintained protective antibody levels for only 21 days. Three weeks after the titres fell below the minimum protective level of 0,15 units/ml, both these groups were treated again in the same manner. The passive immunity conferred in both groups now lasted for 42 days. When the hyperimmune serum was administered to lambs already immunized by vaccination, a slight increase was noted in the antibody titre.     

Humoral immune response of sheep to infection with Eperythrozoon ovis

Circulating antibody was detected by an indirect fluorescent antibody test (IFAT) in the serum of sheep infected experimentally with Eperythrozoon ovis. Antibodies were first detected 15 to 32 days after infection with E ovis and titres peaked at 41 days. This antibody may be associated, at least in part, with protection against infection with E ovis since the initial increase in antibody titre coincided with a fall in the primary parasitaemia. A role for antibody is suggested further by the fact that the prepatent period of infection was prolonged by one day and the parasitaemia initially remained at low levels in infected sheep protected by passively transferred hyperimmune serum. Moreover, following primary infection, acquired immunity was manifest by a lack of parasitaemia following challenge infections while increased IFA titres were observed. No evidence of opsonic activity was observed in an in vitro erythrophagocytosis test in that neither mouse macrophages nor sheep monocytes phagocytosed E ovis infected or uninfected erythrocytes sensitised with hyperimmune serum.     

卵黄抗体对鸽毛滴虫与白色念珠菌感染的治疗效果

旨在研究鸽毛滴虫与白色念珠菌二联卵黄抗体制备方法和评价其临床效果。利用临床分离的白色念珠菌与毛滴虫制备二联灭活疫苗,免疫产蛋母鸡获得高水平抗体,采取低温冻干技术制备成卵黄抗体粉。建立ELISA抗体检测法测定卵黄抗体水平,确保质量可控;以分离的肉鸽毛滴虫、白色念珠菌制备发病模型,评价卵黄抗体的保护效果。结果表明：二次免疫后,卵黄中毛滴虫抗体和白色念珠菌抗体OD值达到高峰,分别为0.90和0.66,抗体维持时间达到2个月。卵黄抗体按1 g·只^-1口服饲喂5 d后,肉鸽口腔和嗉囊病变评分与感染对照组相比显著降低（P<0.05）,与甲硝唑、制霉菌素无差异;此外,毛滴虫、白色念珠菌病原载量极显著降低（P<0.01）。研制的鸽毛滴虫与白色念珠菌二联卵黄抗体可以替代甲硝唑和制霉菌素,为肉鸽的健康养殖提供一种新的抗菌素替代产品。     

Antibody responses following administration of a Cryptosporidium parvum rCP15/60 vaccine to pregnant cattle

Cryptosporidium parvum is a zoonotic Apicomplexa-protozoan pathogen that causes gastroenteritis and diarrhea in mammals worldwide. Globally, C. parvum is ubiquitous on dairy operations and is the pathogen most commonly diagnosed in association with calf diarrhea. Here, we describe the antibody response in 20 pregnant cows to a recombinant C. parvum oocyst surface protein (rCP15/60) vaccine compared with 20 controls, and the antibody response in 19 calves fed the rCP15/60-immune colostrum from these vaccinated cows compared with 20 control calves. Cows vaccinated with rCP15/60 produced a significantly greater antibody response compared to controls (p<0.0001) and this response was strongly associated with the subsequent level of colostral antibody (r=0.82, p<0.0001). Calves fed rCP15/60-immune colostrum showed a dose-dependent absorption of antibody, also associated with colostral antibody levels (r=0.83, p<0.0001). Currently, drug therapy against cryptosporidiosis is limited making development of an effective vaccine attractive. This report describes the first stages in development of a C. parvum rCP15/60 vaccine designed to confer passive protection to calves against cryptosporidiosis.     

Isolation and characterization of antibodies to Clostridium perfringens epsilon toxin from hyperimmune horse serum.

Antibodies against epsilon toxin were isolated from hyperimmune horse serum by affinity chromatography. Purified epsilon prototoxin covalently bound to Affigel 202 was used as immunosorbent, and antibodies were eluted with 6.0 M guanidine chloride. In a single run 80 mg of antibody could be recovered from a 20 microliter column of immunosorbent. The antibody was shown to belong to the IgG(T) class of immunoglobulins.     

Effect of prophylactic administration of hyperimmune plasma to prevent Rhodococcus equi infection on foals from endemically affected farms

The effect on foals of prophylactic administration of hyperimmune plasma to prevent R. equi infection was investigated on three farms at which R. equi infection was endemic. Sixteen foals between 10 and 39 days of age were intravenously given 1-21 of hyperimmune plasma. ELISA antibody titres against R. equi were significantly increased and maintained at high levels for over 30 days in most of the recipient foals. The prevalence of R. equi infection was 6.3% (1/16) in the foals that received the immune plasma, and 26.3% (5/19) in the control foals not given the immune plasma on the three farms. For 2 years before and after this field trial on the three farms, 18 of 64 foals (28.1%) showed clinical signs of respiratory tract infection and four of them died of R. equi pneumonia. Heavy contamination of horses and their environment with virulent R. equi was detected by colony blotting, and plasmid profiles also suggested that foals on the three farms were constantly exposed to virulent R. equi. The results of this field trial support previous observations by some researchers that the administration of hyperimmune plasma to foals in the early days of life promotes prevention of R. equi infection on endemic farms; however, the mechanism of hyperimmune plasma protection remains unclear.     

Cryptosporidium antibodies in manitoba cattle: a pilot study using an indirect fluorescent antibody procedure

An indirect fluorescent antibody test, using feces-derived oocysts as antigen, was used to detect antibodies to Cryptosporidium spp. in bovine sera in Manitoba. Antibodies were detected in 29 of 50 (58%) sera collected from animals of various ages on farms where calves had laboratory-confirmed cryptosporidiosis and in 76 of 186 (40.9%) sera collected at random from culled breeding stock. Serum antibody, presumably colostral in origin, did not appear to protect young calves from the infection. No geographic preference for the infection was demonstrated.     

抗猪繁殖与呼吸综合征病毒卵黄抗体的制备及临床应用

制备猪繁殖与呼吸综合征病毒高免卵黄抗体,研究其治疗效果。以猪繁殖与呼吸综合征灭活苗免疫产蛋鸡,采用ELISA方法检测卵黄抗体效价,收集高效价卵黄,采用氯仿抽提和硫酸铵盐析法纯化卵黄抗体。ELISA方法测定收集抗体效价为1∶8 000,测定纯化的抗体浓度为7.85mg/mL,微生物学检验及安全性试验表明制备的卵黄抗体安全可靠,人工感染治愈率和临床应用治愈率分别为100%和89.1%,表明制备的卵黄抗体对猪繁殖与呼吸综合征具有显著的治疗效果。     

Prophylactic use of hyperimmune serum in experimental colisepticaemia in calves.

Evidence is presented to demonstrate the efficacy of an intravenously administered polyvalent hyperimmune serum prepared from bovine serum, in the prevention of experimental colisepticaemia produced by oral challenge with E coli O78: K80(B) in colostrum deprived calves. It is suggested that the protection afforded by this hyperimmune serum is due to high levels of specific antibody demonstrable in the serum of calves post treatment and that protection is given in this instance by antibodies contained in the IgG class of immunoglobulins.     

Prevalence of cryptosporidiosis in dairy cattle, cattle-keeping families, their non-cattle-keeping neighbours and HIV-positive individuals in Dagoretti Division, Nairobi, Kenya

This paper reports a study estimating the prevalence of cryptosporidiosis, an emerging zoonosis, in people and cattle in Dagoretti, Nairobi. A repeated cross-sectional survey was carried out among randomly selected cattle keepers in Dagoretti, their dairy cattle and their non-cattle-keeping neighbours in the dry and wet seasons of 2006. A survey was also carried out among a group of people living with human immunodeficiency virus (HIV). Faecal samples were examined for Cryptosporidium oocysts using the modified Ziehl-Neelsen method; 16?% of the samples were also examined using immunofluorescence antibody (IFA) technique. Quality control consisted of blind reviews of slides, examining split samples and confirming slide results with IFA. We found that members of dairy households had a dry season cryptosporidiosis prevalence of 4?% and wet season prevalence of 0.3?%, and non-dairy households, a prevalence of 5 and 0?%, respectively. The cattle dry season prevalence was 15?%, and the wet season prevalence, 11?%. The prevalence in people living with HIV was 5?%. The laboratory quality control system showed some inconsistency within and between different tests, indicating challenges in obtaining consistent results under difficult field and working conditions. In conclusion, this is the first reported study to simultaneously survey livestock, livestock keepers and their neighbours for cryptosporidiosis. We failed to find evidence that zoonotic cryptosporidiosis is important overall in this community. This study also draws attention to the importance of quality control and its reporting in surveys in developing countries.