肉仔鸡传染性法氏囊病混合感染白痢杆菌病的诊断与防治

鸡传染性法氏囊病(IBD)是由病毒引起的鸡的一种急性、高度接触性传染病,在我国的流行非常广泛。本病主要侵害免疫中枢器官—法氏囊。因法氏囊被破坏,使鸡降低其对各种传染病的抵抗力并造成鸡对免疫接种的应答反应低下或造成免疫失败,患病鸡群常继发感染新城疫、大肠杆菌病、球虫病、白痢病等。2006年1月宣化区某鸡场发生了鸡传染性法氏囊病及白痢病混合感染,现将诊治情况报告如下。1发病情况春光乡大北街村某户饲养肉仔鸡1500只,从2006年1月份起,鸡群开始发病,发病率85%,死亡率40%。以后经法氏囊苗免疫的鸡群仍然有很大一部分发病,发病率3…     

用大肠杆菌K99和F41菌毛抗原检测牛血清抗体的琼脂扩散试验的研究

用含２ｍｏｌ／Ｌ尿素的磷酸盐缓冲液以热处理方法提取的Ｋ９９和Ｆ４１菌毛作为抗原,对琼脂扩散试验方法进行研究。结果表明本试验方法简便,特异性强,敏感性高,可用于血清抗体检测;所制备的抗原稳定、重复性好。     

非洲猪瘟病原学检测技术研究进展

非洲猪瘟(African swine fever,ASF)是由非洲猪瘟病毒(African swine fever virus,ASFV)感染家猪和野猪而引起的一种急性烈性、高度接触性传染病,到目前为止仍未研制出有效疫苗,因此病原的早发现对ASF防控尤为重要.ASFV的病原学检测主要包括活病毒检测、核酸检测和抗原检测....     

Sarcocystis sinensis is an ultrastructurally distinct parasite of water buffalo that can cause foodborne illness but cannot complete its life-cycle in human beings

In this study, we compared the morphology of Sarcocystis sinensis and Sarcocystis hominis, and assessed the infectiousness of S. sinensis for human volunteers. The cysts of S. sinensis were from water buffalo (Bubalus bubalis) and those of S. hominis were from cattle (Bos taurus). Transmission electron microscopy of S. sinensis cysts revealed that the cyst wall had leaning, finger-like protrusions measuring 1.44-5.08 μm in length and without invaginations on the tip surface of the protrusions. In contrast, the cyst wall of S. hominis had upright, finger-like protrusions measuring 9.43 μm×2.42 μm and with vesicle-like invaginations on the tip surface of the protrusions. Scanning electron microscopy revealed that surface of the protrusions was arranged as rectangles in S. sinensis, as compared to tongue-shaped in S. hominis. Other distinguishing features of S. sinensis include a thin ground substrate (GS) zone with microtubules and small, circle-like structures located at the base of the protrusions. Human volunteers, after consuming S. sinensis cysts, produced no sporocysts or oocysts in feces, suggesting that humans could not serve as definitive hosts for S. sinensis. By contrast, many sporocysts and oocysts were passed in feces of a human volunteer 11-29 days after ingestion of S. hominis cysts. These results showed that S. sinensis and S. hominis are separate species and S. sinensis cannot use human being as the definitive host.     

Fatal infection in human flora-associated piglets caused by the opportunistic pathogen Klebsiella pneumoniae from an apparently healthy human donor

Seventeen out of 24 human flora-associated (HFA) piglets died after oral administration of whole fecal flora from an apparently healthy human donor. The bacteria isolated from the organs of the infected piglets were identified as Klebsiella pneumoniae by bacteriological and biochemical tests and 16S rRNA gene sequence analysis. The identical K. pneumoniae strain was also isolated from the donor's fecal flora. All three neonatal piglets inoculated with K. pneumoniae from the donor's fecal flora developed severe diarrhea, with 2 eventually dying. This strongly suggests that the opportunistic pathogen K. pneumoniae from the human donor caused the fatal infection in the HFA piglets. The results underscore the importance of safety evaluation of the human donor's fecal flora for HFA piglet development.     

产蛋下降综合征（EDS－76）病毒DNA探针的制备及应用研究

用纯化的产蛋下降综合征（ＥＤＳ－７６）病毒（Ｈ９１毒株）悬液提取的核酸，经琼脂糖凝胶电泳只出现１条分子量较大、背景清晰的核酸带。用ＢａｍＨＩ酶消化产生４个片段，大小分别为１７ｋｂ、１０ｋｂ、４．０ｋｂ和２．０ｋｂ。将其中的２．０ｋｂ片段克隆进ｐＵＣ１８ＤＮＡ载体中，重组质粒ＤＮＡ用ｄｉｇｏｘｉｇｅｎｉｎ标记作为ＤＮＡ探针，在ｄｏｔｂｌｏｔ中该探针不与鹅胚尿囊液核酸抽提物、马立克氏病病毒（ＭＤＶ）ＤＮＡ、鸡传染性贫血病毒（ＣＡＶ）ＤＮＡ、ＳＰＦ鸡基因组ＤＮＡ等核酸反应，只与３株ＥＤＳ病毒（ＥＤＳ标准毒株ＡＶ－１２７、ＥＤＳＨ９１毒株和从健康鹅体中分离的ＥＤＳＹ８１毒株）ＤＮＡ呈阳性反应。人工感染产蛋母鸡和雏鸡后２４ｈ即可用该探针从泄殖腔棉拭子样品中检测出ＥＤＳ病毒ＤＮＡ，在感染后３５ｈ仍能从部分感染鸡样品中检出。对部分探针检测阳性鸡的泄殖腔棉拭子样品用ＳＰＦ鸡胚分离病毒，并用ＨＡ和ＨＩ试验检测分离病毒的特异性；在感染过程中，同时检测了血清中ＨＩ抗体的消长情况。结果表明，人工感染鸡排毒至少可以维持２个月左右，而且血清中ＨＩ抗体即使很高，也不能阻止感染鸡的排毒。     

实验性雏鸡佝偻病的病理学研究——Ⅱ.形态学观察

4日龄 Aiboi Acies肉鸡健雏80只随机分为4组,分别喂给钙-磷缺乏(Ca 0.02％,P0.30％)、缺钙(Ca 0.02％,PO.71％)、缺磷(Ca 0.95％,PO.30％)和正常对照(Ca 0.95％PO.71％)日粮三周,进行了系统的病理形态学观察。缺磷组病变表现为肋骨头肿大,长骨骨骺生长板之肥大带明显增宽,骨小梁减少;缺钙组和钙-磷缺乏组病变表现为肋骨增粗弯曲,长骨骨骺生长板之增生带显著增宽,海绵骨类骨组织和结缔组织大量增生,成骨细胞和破骨细胞丰富。结果表明,钙缺乏和磷缺乏所致病变显著不同,为鉴别诊断提供了科学依据。     

我国部分地区Sicinivirus流行病学调查

Sicinivirus是一种禽类新发病毒,可引起家禽发育迟缓综合症、腹泻、吸收不良综合征等.目前,仅部分国家开展了该病毒的流行病学调查,研究数据极为有限.为明确该病毒在我国的流行情况,以及该病毒感染率与地域、宿主、养殖方式之间的关系,2019年下半年在江苏、广西、河北、安徽、广东、上海、湖北和江西8个省(自治区、直辖市...     

猪瘟活疫苗(种毒)鉴别检验阳性血清制备

为制备猪瘟活疫苗(种毒)鉴别检验阳性血清,本实验将4头非免疫健康猪进行猪瘟活疫苗基础免疫和猪瘟石门强毒株反复强化免疫后,采血分离血清,过滤、分装、冻干、熔封,获得4批产品,并进行了检验和验证。结果显示:物理性状、无菌检验、安全检验、均一性检验、支原体检验、真空度测定均合格;剩余水分均小于4%;特异性检验表明,口蹄疫病毒、猪伪狂犬病病毒、猪繁殖与呼吸综合征病毒、猪细小病毒、牛病毒性腹泻/粘膜病病毒抗体均为阴性;残余猪瘟病毒免疫荧光和套式RT-PCR核酸检测结果均为阴性;兔体中和效价分别为1∶800、1∶800、1∶800和1∶1 600;对猪瘟兔化弱毒种毒和5种猪瘟活疫苗的验证结果均良好。该4批血清可以用于猪瘟活疫苗(种毒)鉴别检验。     

苏云金芽孢杆菌YJ-2000菌株对家蚕安全性和杀虫活性的评价

应用时间-剂量-死亡率模型就苏云金芽孢杆菌(Bacillus thuringiensis)YJ-2000菌株对6种鳞翅目昆虫的杀虫活性作了初步评价。该菌株对家蚕基本无毒性,而对蔬菜害虫小菜蛾、菜粉蝶,水稻害虫三化螟、二化螟,桑树害虫桑螟幼虫均有不同程度的毒性,其中对小菜蛾和菜粉蝶的毒性最强;幼虫死亡率可高达100％。该菌株是对家蚕安全而对其它鳞翅目害虫具杀虫活性的特异性菌株,有望用于养蚕地区桑园及其邻近作物的鳞翅目害虫防治。