长沙地区奶牛无浆体动物感染试验及其传播途径调查

采集长沙地区某奶牛场疑似患病牛鲜血及牛舍周围吸血类昆虫(牛虻、厩蝇和蚊子等),分别作镜检观察,腹腔接种至试验小鼠体内(0.5 mL/只)进行培养和观察.为进一步证明其传播途径,将12只试验兔分别放置于牛舍不同方位饲养1周,进行临床感染试验.结果表明,病牛鲜血涂片染色后在血液红细胞内观察到呈圆点状或球状的无浆体虫体,绝大部分位于红细胞边缘,少数位于中央,染虫率达30%,患牛抗凝血在试验小鼠体内进行培养后,第4天开始在小鼠红细胞内查到虫体,第17天达到感染高峰;吸血类昆虫血液涂片、染色后,其中385片在血液红细胞内观察到虫体,虫体查出率达77%;吸血昆虫内容物在试验小鼠体内的培养情况大致与患牛抗凝血情况相同;在临床感染1周后的第6天,7只兔在血液红细胞中查到虫体,兔感染率达75%.     

人工感染吉氏巴贝斯虫后犬脾脏病理学变化

为了明确吉氏巴贝斯虫感染后犬脾脏的病理学变化，本试验采用静脉接种的方法感染健康犬，每只犬接种含吉氏巴贝斯虫的血液5 mL(红细胞染虫率约2%),接种后每3天采集1次血液，通过血涂片、血常规、PCR等方法监测吉氏巴贝斯虫是否感染成功；每7天采用B超检查脾脏的大小；对发病死亡犬进行病理剖检和组织病理学检查，观察脾脏病理组织结构的变化。结果显示，人工接种吉氏巴贝斯虫3 d后PCR可检测到虫体DNA,6 d后血涂片可见虫体，15 d后血常规指标(红细胞总数、血红蛋白含量和红细胞压积)开始降低。B超检查结果显示，犬感染吉氏巴贝斯虫后其脾门、脾尾厚度随病程延长逐渐增大。于感染后第31、36天和第42天试验犬分别死亡1只，死亡率为50%,剖检死亡犬可见其皮下黏膜黄染，脾脏肿大，被膜紧张，边缘钝圆，脾梗死。组织病理学观察可见脾脏充血，白髓、红髓界限不清，大量中性粒细胞、单核巨噬细胞浸润，结缔组织增生，脾小梁增粗，梗死灶内大面积坏死，淋巴细胞减少，中性粒细胞浸润。由此可见，在吉氏巴贝斯虫感染过程中脾脏首先发生急性炎性脾肿，随着病程延长逐渐演变成坏死性脾炎和慢性脾炎。     

卡氏住白细胞虫配子体的浓集和纯化

以淋巴细胞分离液和生理盐水为介质，分别按不同比例配制成3种不同密度（1.060g/ml、1.070g/ml、1.073/ml)的分离液，并通过无菌采集患卡氏住白细胞虫病的病鸡血液获得了卡氏住白细胞虫的配子体。采用单密度梯度离心法和多密度梯度离心法对该配子体进行了浓集和纯化。进行最佳离心速度和离心时间的筛选结果显示，1500r/min离心25分钟分离效果最佳；经多密度法离心后可同时获得浓集和纯化的配子体；经单密度法离心后，只能得到浓集的配子体；对浓集的虫体进一步纯化，结果显示纯化率可达95％以上。通过密度梯度离心的结果判定，配子体的密度介于1.070-1.073g/ml之间。实验结果表明若需要大量分离纯化配子体，应以单密度法分二步进行为佳；若只需少量纯化的虫体，则可用多密度法一步来完成。     

小鼠肠期旋毛虫及其所致病变的形态学观察

小鼠血液中出现移行性幼虫的最早时间是在旋毛虫感染后的第6d,虫体多呈直杆状,表面光滑,其大小为116～121μm×4～5μm。感染后第2d旋毛虫即钻入肠绒毛,第3d发现虫体的脱皮现象,肠旋毛虫具有发达的横纹和纵纹,第5、6、7d肠道出现卡他性和出血性肠炎变化.     

吉氏巴贝斯虫实验动物模型的研究

用吉氏巴贝斯虫感染置换了犬红细胞的SCID鼠,吉氏巴贝斯虫在SCID鼠体内得到高水平的生长和增殖.虫体大小比在犬体内略增大,而且繁殖型虫体增多,常在一个红细胞内寄生有2、4、8、16和32个虫体.在感染的第10天前后,末梢血液中红细胞的染虫率高达12%左右.从SCID鼠末稍血液能检出虫体的期限为15～18天左右.从而成功地建立了吉氏巴贝斯虫的实验动物模型.     

脆弱艾美尔球虫在鸡胚培养中内生性发育史的研究

脆弱艾美尔球虫在鸡胚培养中,可以像在鸡的肠道内一样地完成全部内生性发育史。用体外脱囊的球虫子孢子接种于9～11仅龄鸡胚的尿囊胜中。在40℃～41℃下培养,可在绒毛尿囊膜细胞内观察到无性世代和有性世代两个发育阶段。出现第一、二、三代裂殖体,以及大配子体、小配子体和卵囊。成熟的第一代裂殖体在绒毛尿囊膜细胞内最早出现于感染后48小时,第二代为94小时,第三代为132小时。大配子体和小配子体、卵囊分别于感染后132和144小时形成,均寄生在绒毛尿囊膜表层。各期虫体的发生时间与鸡体内基本相似,从子孢子开始到产生次代卵囊,完成全部内生性发育需要144小时。     

莫氏巴贝斯虫和羊巴贝斯虫在我国的分离及形态学观察

在甘肃省庆阳地区的发展及病愈的小尾寒羊血液中分离出２种巴贝斯虫并进行了形态学观察，初步证实该地区“坏肠子”病的病原为巴贝斯虫。一种小型虫体鉴定为羊巴贝斯虫，另一种为大型虫体，鉴定为莫氏巴贝斯虫，含羊巴贝斯虫的血液注射给除脾羊后，第１４ｄ血涂片中红细胞的染虫率达最高点（为０．５％），之后逐渐下降，感染羊自然耐过，含有混合虫种的血液注射给易感除脾羊后，红细胞染虫率迅速上升到３０．０％，感染后第６ｄ羊因     

实验感染肝片吸虫山羊的病理生理学Ⅰ．血液生理生化指标及抗体动态

给山羊分别实验感染肝片吸虫囊蚴200、500个／只，感染后每周颈静脉采血1次，测定血液生理生化指标和抗体动态的变化。结果表明，山羊实验感染肝片吸虫后，血液中RBC、Hb明显下降；WBC和嗜酸性粒细胞数显著增加；血清中谷－草转氨酶（AST）从第2周开始上升，第8周和第9周达到峰值；γ-谷氨酰转肽酶（GGT）于感染后第7周和第8周开始升高，第10周和第11周达高峰；以ELISA检测抗体表明，2个试验组山羊感染后血清中IgG分别在第9周和第6周达峰值，随后均稍有下降，一直呈波动趋势，但在整个试验期内，一直高于对照组（P＜0．05或P＜0．01）。分析认为，山羊感染肝片吸虫后表现的贫血是正细胞正色素型，伴有低白蛋白性，肝脏损伤明显，体液免疫反应增强。     

北京鸭毁灭泰泽球虫Tyzzeria perniciosa内生发育的研究

作者对北京鸭毁灭泰泽球虫的内生发育进行了研究,所得结果如下: 1.感染后48小时发现第一代裂殖体,寄生在肠绒毛远端部上皮细胞核的上方。肠绒毛的基部、肠腺和固有层中未发现虫体。在第一代裂殖体出现的最早时间上,我们的结果和Allen(1936)的报道不同,该作者于感染后24小时见到第一代裂殖体。而和Versenyi(1967)的报道相一致,该作者亦于感染后48小时发现第一代裂殖体。但Versenyi所报道的裂殖体偏大,寄生于粘膜间质细胞中。 2.感染后96小时发现第二代裂殖体,比Allen(1936)和Versenyi(1967)所报道的偏小。 3.Allen(1936)认为毁灭泰泽球虫内生发育的无性世代,至少有三代,Versenyi(1967)认为不大可能多于两代。我们认为最大可能是两代:第一代裂殖体最早出现于感染后48小时,延续到84小时,寄生于肠绒毛上皮细胞核的上方,个别的在核下方,靠近固有层;第二代裂殖体最早发现于感染后96小时,延续至120小时,寄生于肠绒毛上皮细胞核的下方和固有层以及肠腺腺细胞核的内侧。 4.感染后96小时发现大小配子体,延续到120小时以后,直至143小时仍能在12指肠和卵黄蒂前后肠段绒毛固有层中见到大配子。Allen报道感染后48小时出现大小配子体;Versenyi(1967)报道最早于感染后96小时出现配子细胞。 5.感染后104—120小时发现卵囊;到感染后144—216小时,即不再发现裂殖体和大、小配子体,亦未见卵囊。感染后第五天(118小时),随粪便排出卵囊。 6.内生阶段的虫体寄生于12指肠、空肠和回肠(整个小肠),尤以卵黄蒂前后段受侵害最为严重。感染严重时,盲肠和直肠也见有虫体。     

柔嫩艾美耳球虫感染鸡的体液免疫机理研究

为了揭示鸡柔嫩艾美耳球虫（E．tenella）病的免疫机制，试验从分子水平、细胞、亚细胞对人工攻毒病鸡特异性抗体、免疫细胞的动态变化及在抗球虫中的作用进行了探讨，试验结果如下：一是雏鸡感染E．tenella后，第6天即可在外周血液中检测出特异性IgG，于第18天达到峰值，第23天开始下降，第30天时降至感染后第7天的水平；二是揭示了雏鸡感染E．tenella后，鸡体IgG生成细胞的动态变化规律为：主要免疫器官胸腺、法氏囊、脾脏、盲肠扁桃体和盲肠局部的IgG生成细胞于第2天和第3天开始增殖，在第9天至第16天达到峰值，然后逐渐下降，盲肠扁桃体中的IgG生成细胞在第18天降至对照组水平，盲肠、脾脏和法氏囊中的IgG生成细胞数在第22天仍高于对照组，且差异显著。     

Some observations on the adaptation of Eimeria tenella (local isolates) sporozoites on chicken embryos through chorioallantoic membrane

Eimeria (E.) tenella (local isolate) sporozoites were adapted on the chorioallantoic membrane (CAM) of 10-12 days chicken embryos and completed its life cycle in 6~7 days at 39℃ and 70 per cent humidity. Only 23 embryos (4.6%) were found dead from 1~4 day post inoculation of sporozoites with mild lesions on CAM with no gametocytes but few sporozoites in chorioallantoic fluid (CAF). On 5~7 day post inoculation, 432 embryos (86.4%) were found dead with severe haemorrhages on CAM and CAF contained uncountable number of gametocytes. After seven days post inoculation, 45 embryos (9%) were found to be alive. Some oocysts were also detected in the CAF on 6~7 days post inoculation. In the histological sections of the CAM, there were abundant small dark colored rounded bodies of gametes; distributed extensively in tissues of CAM on 5~7 days post inoculation of sporozoites. In some cases, cluster of small mature and immature relatively large bodies were seen in increasing numbers on 5~6 days post inoculation.     

Role of reticulocytes on gametocytogenesis in chickens infected with Leucocytozoon caulleryi

Reticulocytes, known as late polychromatic erythrocytes, were induced in blood of chickens infected with Leucocytozoon caulleryi by bleeding when the second-generation merozoites were released into the blood from the second-generation schizonts. The second-generation merozoites preferentially invaded into reticulocytes and developed to stage II gametocytes. Enhanced development of stage II gametocytes to mature gametocytes was observed in the reticulocytes in vivo and in vitro in the bleeding group. Nevertheless, invasion of reticulocytes by the second-generation merozoites was not considered to be absolutely necessary for the development of gametocytes.     

Diagnosis of Hepatozoon spp. in Amblyomma ovale and its experimental transmission in domestic dogs in Brazil

Transmission of Hepatozoon spp. to dogs was investigated using four species of ixodid ticks: Rhipicephalus sanguineus, Amblyomma aureolatum, Amblyomma ovale and Amblyomma cajennense. We collected completely or partially engorged adult ticks of these species from dogs that were naturally infested and positive for Hepatozoon spp. We selected some of these ixodids and inoculated them orally in four negative dogs. The other ticks were dissected and examined for oocysts. Of all dogs inoculated orally with R. sanguineus, A. aureolatum, A. cajennense and A. ovale, only the animal that received the macerate of A. ovale was positive; evidence (gametocytes in peripheral blood) of infection was found 63 days after inoculation. Among all dissected ticks, we found only two oocysts; these were similar to those of Hepatozoon canis, and both were recovered from a single A. ovale specimen. We inoculated sporozoites recovered from the oocysts intraperitoneally into a Hepatozoon spp. negative dog, and circulating gametocytes were detected 84 days later. Our study demonstrated that A. ovale can be a vector of Hepatozoon spp. in Brazil.     

Elimination of the gametocytes of Theileria annulata of cattle by primaquin phosphate

Calves were experimentally infected with Theileria annulata and five drugs were administered in an attempt to exterminate the gametocytes of the parasite. The results of the experiment proved that primaquin phosphate is an effective parasiticide. The gametocytes from 30 calves treated with primaquin phosphate were exterminated completely. A further eight calves were treated with sulfamethoxypyrazine, trimethoprim, naganin and acaprin, but these drugs were not found to be effective in eliminating the gametocytes. The phase, size and colour of the gametocytes in these calves were the same as those of the four untreated control calves.     

巨型艾美球虫重组蛋白Gam82-Y和重组质粒pcDNA-gam82的免疫保护效果研究

为研究巨型艾美球虫NT株重组蛋白Gam82-Y和重组质粒pcDNA-gam82对鸡的免疫保护效果,本研究以平均增重、相对增重率及卵囊减少率等作为评价指标,检测结果显示:中剂量重组蛋白佐剂组(0.5 mg-FCA)和中剂量重组蛋白组(0.5 mg)的免疫保护力均低于卵囊免疫组(p＜0.05),但比其他各免疫组高(p＜0.05);重组质粒(pcDNA-gam82)免疫组的平均增重、相对增重率、卵囊减少率等方面与重组蛋白免疫组相同,两者均优于未免疫攻虫组(p＜0.05),但仍未能够达到卵囊免疫组的免疫保护水平(p＜0.05).     

巨型艾美球虫gam56基因的截短原核表达及其产物的免疫保护效果

为评价gain56基因重组表达产物作为亚单位疫苗预防鸡巨型艾美球虫(E.maxima),感染的效果,以E.maxima NT株配子体总RNA为模板,RT.PCR扩增和克隆gain56基因,选择该基因两段丰富抗原表位的编码区片段.利用原核表达载体pGEX-6P-1在大肠杆菌中进行截短表达.以可溶性的GST-gain56-2融合蛋白为免疫原,设立高、中、低(1.0 mg、0.5 mg、0.25 mg)3个剂量,单独或使用弗氏完全佐剂,于5 d、12 d和19 d对雏鸡进行3次免疫,26 d用5 ×10~4个E.maxima孢子化卵囊进行攻虫,8 d后迫杀,对各组的存活率、相对增重率、卵囊减少率、ACI等指标进行统计分析.结果显示:就相对增重率而言各免疫组比未免疫攻毒组的高27.6%以上,而各免疫组之间差异不显著(p>0.05);就卵囊减少率指标而言,各免疫组较未免疫攻毒组均有不同程度减少,但是均小于75%;就ACI指标而言,各免疫组较未免疫攻毒组均有不同程度增加,以中剂量蛋白佐剂组为最高.GST-gam56-2融合蛋白对于E.maxima感染具有一定的免疫保护效力.     

雏鸡实验感染柔嫩艾美尔球虫的病理学研究

１１４只２３日龄无球虫罗斯小公鸡，分为三组，第１和第２每只鸡分别口服１．０８×１０＾５和５．４２×１０＾４个柔嫩艾美尔球虫孢子化卵囊，第３组对照。结果，第１、２组在感染后第４天呈现血便，第５天发性死亡，其死亡率分别为１３．６％５０和５．４％。尸体剖检，盲肠明显肿大，肠壁出血；后期，盲肠萎缩，并出现干酪样肠 芯。病理组织学变化特点，为出血一坏死性或出血一卡地他性盲肠炎，以及出血一卡他性直肠炎。第８天     

Hepatozoon canis infection in dogs: clinical and haematological findings; treatment

Hepatozoon canis gametocytes were identified in the circulating neutrophils of six dogs from different parts of southern Israel. Clinical signs included fever, anaemia, anorexia, weakness of the hind legs and numerous brown dog ticks (Rhipicephalus sanguineus) on the skin surface. Parasitaemia varied from 6 per cent to 43 per cent of the circulating neutrophils. Two of these six cases also showed Ehrlichia morulae in the cytoplasm of leucocytes. Drug therapy with tetracycline hydrochloride 22 mg/kg, three times daily, and imidocarb dipropionate, 6 mg/kg, by subcutaneous injection, repeated after 14 days, was accompanied by clinical improvement and the depression of gametocyte parasitaemia.