柔嫩艾美耳球虫的分离鉴定与致病性测定

本实验采用单卵囊分离技术分离纯化球虫,并根据其临床病理变化、潜隐期、最短孢子化时间等指标综合判定其为柔嫩艾美耳球虫。用纯化所得球虫卵囊进行致病性试验,结果表明:该柔嫩艾美耳球虫致病力较强,半数致死量为7.52×104个/只。     

鸡艾美耳球虫哈尔滨株的分离与鉴定

为研究鸡艾美耳球虫哈尔滨株单一虫种的生物学特性,本研究利用单卵囊分离技术分离了6种鸡艾美耳球虫哈尔滨株,用分离的单卵囊接种雏鸡,同时应用PCR方法对收集的单卵囊分离株进行球虫种类鉴定并进行同源性和系统进化分析.结果显示,分离得到的6株鸡艾美耳球虫分别为柔嫩艾美耳球虫、毒害艾美耳球虫、堆型艾美耳球虫、早熟艾美耳球虫、和缓艾美耳球虫和布氏艾美耳球虫,PCR结果表明单卵囊分离株确为该6种纯株.本研究表明毛细吸管单卵囊分离法简便易行,使接种难度降低,提高了接种成功率,为球虫的分子生物学研究奠定了基础.     

鸡巨型艾美耳球虫单卵囊分离及雏鸡扩增试验

采用饱和食盐水漂浮法收集就诊病死球虫阳性鸡小肠中段内容物中的球虫卵囊,恒温培养至孢子化后,用2%琼脂薄板进行球虫单卵囊分离,分别感染7只5日龄雏鸡,对据形态学鉴定为巨型艾美耳球虫的分离株进行2代单卵囊分离和雏鸡感染,取其后代以每只1.0×10⁴个卵囊感染10只10日龄雏鸡进行卵囊扩增,获得大量纯种巨型艾美耳球虫卵囊。结果表明,刀片切割琼脂薄板单卵囊分离法操作简便,单卵囊感染成功率较高,准确率达100%,适用于纯种卵囊的分离与扩增。     

影响巨型艾美耳球虫单卵囊纯化试验成功的因素分析

鸡球虫病是重要的寄生性原虫病,由顶复器门的艾美耳属(Eimeria)球虫感染引起,全世界每年因球虫病造成的损失约80亿美元。巨型艾美耳球虫(Eimeria maxima)是鸡的9种球虫之一,也是集约化养鸡场最常见的三种球虫之一,危害严重,呈世界性分布,我国已有25个省(市、区)报道存在。1929年     

鸡艾美耳球虫单卵囊分离技术的建立

以玻璃纸做材料,用毛细吸管分离单卵囊,通过显微镜"重复"鉴定法,对柔嫩艾美耳球虫(Eimeria tenella)进行分离.单卵囊感染20只鸡,在感染后5 d～15 d,用饱和盐水漂浮集卵法进行检测.结果显示,有15只鸡粪便中检出卵囊,经鉴定均为所要分离的虫种(E. tenella),感染成功率为75%,准确率达100%.另外,应用改进后的玻璃纸单卵囊分离技术还成功分离到毒害、巨型、堆型、布氏、和缓和早熟艾美耳球虫的单一虫种.结果表明,改进后的单卵囊分离技术简单易行,感染方便,成功率和准确率都较高,而且所用材料易于获得,消毒方便.     

鸡柔嫩艾美耳球虫和巨型艾美耳球虫双重PCR检测方法的建立

为了建立一种能够快速实现对鸡柔嫩艾美耳球虫(Eimeria tenella)和巨型艾美耳球虫(E.maxima)同时进行检测的双重PCR方法,基于2种艾美耳球虫各自的ITS-1基因筛选2对特异性引物,对制备的阳性DNA样品进行PCR扩增,凝胶电泳检测结果显示,分别在约450bp和150bp处出现目的条带。对PCR反应中的退火温度、MgCl2浓度、DNA模板量等进行优化。结果表明,当退火温度为59℃、MgCl2浓度为2.5mmol/L、DNA模板量为2μL时,双重PCR扩增结果最佳。特异性检测结果显示,所建立的双重PCR对环形泰勒虫、羊巴贝斯虫、隐孢子虫和蓝氏贾第虫的扩增结果均呈阴性,表明建立的方法具有较高的特异性。成功建立了柔嫩艾美耳球虫和巨型艾美耳球虫双重PCR检测方法,为临床中鸡球虫病的快速诊断提供了一种可靠的检测方法。     

针头及透明塑料纸球虫单卵囊分离感染法

球虫卵囊悬液适当稀释后,用14 号注射器针头沾取少许,滴点到放置于载玻片的0.8 cm×0.8 cm大小的透明塑料纸片上,随即置于镜下观察。发现符合条件的单个卵囊后,用镊子夹取玻璃纸片一角,插进鸡的嗉囔中使鸡感染。此技术与其他分离方法相比,用材简单,操作方便,节省时间,成功率高,是一种很实用的方法。     

柔嫩艾美耳球虫病毒的鉴定

鸡球虫病是由艾美耳属（Eimeria）的一种单细胞寄生性原虫引起的严重危害养禽业发展的重要疾病之一,遍及世界各地。感染鸡的艾美耳属球虫中,国外已报道在巨型艾美耳球虫（E.maxima）,堆型艾美耳球虫（E.acervu-lina）,毒害艾美耳球虫（E.necatrix）和布氏艾美耳球虫（E.brunetti）中发现了病毒粒子或病毒RNA。但是作为危害最严重的柔嫩艾美耳球虫是否有病毒感染,国内外迄今尚无报道。本研究首次在柔嫩艾美耳球虫中发现病毒并对其进行了鉴定。通过核酸分析、RNA依赖的RNA聚合酶（RDRP）活性和电镜形态观察对病毒进行鉴定。核酸酶的敏感性试验结果表明在柔嫩艾美耳球虫总核酸电泳图谱上观察到的大小分别为1.4、2.4和3.6kb的3条病毒带均不能被DNA酶（100mg/L）降解,但可被RNA酶（1.0mg/L）降解,表明这些核酸为RNA。另外,这些核酸不能被高盐浓度（0.3mol/L NaCl）RNase A（10mg/L）降解,但可被低盐浓度（0.015mol/L NaCl）RNase A（10mg/L）降解,并且采用α-32P标记的UTP掺入法测得该病毒样核酸具有RNA依赖RNA聚合酶（RDRP）活性,表明这些核酸为双链RNA（dsRNA）。利用蔗糖梯度离心和透射电镜技术对柔嫩艾美耳球虫病毒进行了分离和鉴定。电镜负染观察到柔嫩艾美耳球虫病毒粒子外观呈球形,二十面体,无囊膜,直径38nm。     

鸡堆型艾美耳球虫南昌株分离纯化与初步鉴定

对南昌市场购买的成年鸡肠道,采用饱和盐水漂浮法检查,同时从肠内容物中获取混合球虫卵囊.在制备好的琼脂薄层的载玻片上滴加稀释适度的混合卵囊液.在显微镜下用手术刀片小心切割琼脂薄层,达到琼脂薄层上仅剩单一卵囊的严格要求.把单一卵囊包襄后经口感染雏鸡,又从感染雏鸡粪便中收集大量球虫卵囊待孢子化后再次重度感染雏鸡,掌握该球虫虫...     

巨型艾美耳球虫地方株的分离与鉴定

本文报道对巨型艾美耳球虫长春株的分离鉴定。主要鉴定指标如下:虫体寄生于小肠中段的空肠与回肠,配子体寄生于上皮下。病理变化主要表现为肠管充血、黄染、臌气,粘液性稀便以及肠粘膜针尖大小出血点。卵囊大小为31.5±0.26×23.1±0.15微米。最大裂殖体为9.2微米,潜隐期126±0.15小时,卵囊最短孢子发育时间为28小时。     

特异PCR方法用于鸡的3种艾美耳球虫混合感染鉴别的研究

用单卵囊分离法获得的鸡的3种艾美耳球虫（每种各2株）卵囊：柔嫩艾美耳球虫（Eimeria tenella）、巨型艾美耳球虫（E．maxima）、堆型艾美耳球虫（E．acervulina）。经纯化、提取基因组DNA后，用报道的种特异引物做PCR扩增分析，以确定是否为纯种。结果发现这3种球虫均存在混合感染的情况。该结果为进一步研究这3种球虫奠定了基础，并说明特异PCR方法能够有效地、快速地鉴别球虫虫种。     

Detection of serum antibodies in Eimeria tenella-infected chickens by enzyme linked immunosorbent assay (ELISA) with merozoite and oocyst antigens.

Soluble antigens prepared from sporulated oocytes and second generation merozoites of E. tenella were used for enzyme linked immunosorbent assay (ELISA) to investigate antibody in sera of two breeds of chickens, i.e. commercial broilers and SPF single comb white leghorn layers, which were experimentally infected with E. tenella. In broilers inoculated with oocysts at 15 days of age, ELISA values increased rapidly after day 19 post inoculation (PI) and reached the maximum lebel on days 29 and 32 PI against both merozoite and oocyst antigen. The values against merozoite antigen were significantly higher than those against oocyst antigen. In SPF layers infected at 15 days of age, the values increased gradually after 7 days PI. There were no significant differences between values against two antigens. Generally, the values in broilers tended to be higher than those in SPF layers, especially against merozoite antigen. In broilers inoculated with oocysts at 1 and 15 days of age, ELISA values increased rapidly and reached the maximum level on days 11 and 20 post second inoculation (PSI) against merozoite and oocyst antigens respectively and then the values against merozoite antigen decreased. The values against merozoite antigen were markedly higher than those against oocyst antigen. In SPF layers inoculated twice, the values reached the highest on day 11 PSI as in the case of broiler; however, after that day, the values against both antigens decreased. The sera reacted similarly against both antigens. The values against merozoite antigen were significantly higher in broilers than in SPF layers.(ABSTRACT TRUNCATED AT 250 WORDS)     

鸡球虫卵囊分离纯化与单卵囊制备技术的改进

鸡球虫病是严重危害和制约养鸡业发展的寄生虫病之一,凡是有养鸡的地方就有不同程度的鸡球虫病发生,特别是在集约化养鸡场,其发病率可达到50%～70%,死亡率也达20%～30%,严重时高达80%.对鸡球虫卵囊的分离纯化及单卵囊的制备工作是进行球虫病研究分析的主要工作,也是必备的工作.同时,球虫卵囊的分离技术是鉴别球虫的种类和建立球虫的纯种体系、调查某地区内球虫种类和获得球虫的纯种体系的重要手段,对进一步研究球虫的致病性、药物效应、产生的耐药性和禽体对球虫的免疫性、以及对抗球虫药的开发和球虫疫苗研制有重要意义.在结合科研实践的基础上对鸡球虫卵囊的分离纯化及单卵囊制备的操作方法进行改进,改进后提高了虫卵的回收率及单卵囊制备成功率,减化了工作流程.     

牛隐孢子虫卵囊分离和纯化方法的比较试验

运用3种粪便漂浮法、3种染色法和2种分离提纯法对10头犊牛的粪便进行卵囊检查、分离纯化，对这些方法进行比较。试验结果显示：饱和硫酸锌漂浮法结合姬姆萨氏染色法检查隐孢子虫卵囊，检出率最高、效果最佳；蔗糖密度梯度离心法分离纯化隐孢子虫卵囊。收集的卵囊最多，效果最好。     

毒害艾美耳球虫卵囊壁蛋白的SDS-PAGE及Western blot分析

利用聚丙烯酰胺凝胶(SDS-PAGE)电泳技术,分析了毒害艾美耳球虫未孢子化卵囊壁可溶性蛋白。用鼠抗毒害艾美耳球虫重组配子体蛋白rEnGAM56和rEnGAM59多克隆抗体,对卵囊壁可溶性蛋白进行了Western blot分析。结果显示,至少有24条较清晰的电泳条带,其中6条为相对明显的主带,其相对分子质量分别为37 000,35 000,34 000,20 000,14 000和12 000。Western blot分析显示,鼠抗rEnGAM59和rEnGAM56多抗均能识别1条条带,前者的相对分子质量约14 000,后者约30 000。推测30 000和14 000卵囊壁蛋白分别来自毒害艾美耳球虫配子体蛋白EnGAM56和EnGAM59。     

Specific identification of Pasteurella multocida serogroup-A isolates by PCR assay

A polymerase chain reaction (PCR) assay targeting the hyaC-hyaD gene was developed and used to identify strains of Pasteurella multocida belonging to serogroup-A. A set of serogroup-specific-PCR primers amplified a 564 bp product from genomic DNA prepared from bacterial cells or directly from bacterial colonies. This method detected as low as 10 ng of bacterial DNA and had a specificity of 100% for P. multocida serogroup-A. A nested PCR method yielded a single 374 bp product. All fifty isolates were also shown to be identical by restriction fragment length polymorphism (RFLP) analysis of the PCR products after digestion with BglII.     

Effect of social environment and oocyst dose on resistance and immunity to Eimeria tenella challenge

Chickens were exposed to graded doses of a suspension of Eimeria tenella oocysts while in environments of high (HSS) or low (LSS) social stress. Both primary cellular resistance and the sensitization phase of cell-mediated immunity were higher in the HSS environment than in the LSS environment. The manifestation of cell-mediated immunity seems to be inhibited by social stress.     

Evaluation of a PCR assay for identification and differentiation of Campylobacter fetus subspecies

Objective To evaluate a polymerase chain reaction assay for identification of Campylobacter fetus and differentiation of the defined subspecies.
Design Characterisation of bacterial strains by traditional phenotyping, polymerase chain reaction, a probabilistic identification scheme and macrorestriction profiling using pulsed field gel electrophoresis.
Procedure The results of identification of 99 bacterial strains as determined by conventional phenotyping or by poly-merase chain reaction were compared. Two of these were type strains of C fetus subsp fetus and C fetus subsp venerealis ; the remaining strains were field isolates putatively identified as C fetus . In cases where the subspecies identity was disputed, isolates were identified by means of a probabilistic identification scheme and by macrorestriction profiling.
Results The agreement between strain identities initially suggested by traditional phenotypic methods and the PCR assay was found to be 80.8%. The polymerase chain reaction proved to be a reliable technique for the species and subspecies identification of C fetus ; equivocal results were obtained in only two instances. Initial misidentifications by conventional phenotyping methods were attributed to methodological differences used in various laboratories.
Conclusion Our results indicate that misidentification of C fetus i n routine diagnostic laboratories may be relatively common. The PCR assay evaluated gave rapid and reproducible results and is thus a valuable adjunctive method for the identification of C fetus and subsequent subspecies differentiation.