仔猪腹泻粪样中猪呼肠孤病毒的分离鉴定

通过在病毒培养液中添加胰酶的方法,笔者从仔猪腹泻粪样中分离并鉴定了1株能在Vero细胞上稳定产生CPE,即以细胞颗粒增多、肿胀、漂落为特征的猪呼肠孤病毒SC-A株。在感染细胞中,病毒胞浆包涵体及特征性微管样结构明显,病毒粒子多呈典型的晶格状排列,直径约70 nm。克隆测序结果表明：SC-A S2全基因（DQ396805）大小为1 331 bp,其开放阅读框编码1个由418个氨基酸残基组成、相对分子量约为47.14 ku的σ2蛋白;与标准株T1L、T2J、T3D的核苷酸序列相似性分别为86.9%、76.7%、85.4%,推导氨基酸序列相似性分别为94.6%、93.3%、98.3%。在以σ2氨基酸序列构建的进化树中,标准株及野外分离株可被划分为A、B、C 3个大的进化分支;除T3C31外,其余3型野外分离株及SC-A株和所有血清1型病毒株均位于进化分支C中。     

鸡呼肠孤病毒分离与鉴定

从广西玉林市某鸡场出现跛行、瘫痪、跗趾关节和腱肿胀等症状的不同发病鸡群中分离到两株病毒。经病毒分离培养、理化特性鉴定、血清中和试验、动物回归试验、抗体检测以及PCR诊断,确定所分离到的两个病毒株为禽呼肠孤病毒。     

番鸭呼肠孤病毒的分离与鉴定

本文采用病毒分离鉴定的常规方法,从某番鸭养殖户自然死亡的番鸭中分离到1株病毒,用分离到的毒株试验感染1日龄敏感番鸭,其死亡率达100％,临床及病理变化与自然感染发病的番鸭基本一致,并可回收到该病毒,分离毒株与番鸭呼肠孤病毒有一定的血清学交叉反应。根据试验结果,初步确定该病毒为呼肠孤病毒。     

鹅源番鸭呼肠孤病毒的分离鉴定

近几年,鹅“白点病”频发。本研究从江苏沛县地区肝脏有坏死点的发病鹅中收集肝脏病料,进行病毒分离,通过RT-PCR检测、序列分析进行病毒鉴定,并回归雏鹅进行致病性试验。结果发现：该毒株在鹅胚上生长良好;回归鹅能完全复制出临床中肝脏出现坏死点的病变,并能从实验鹅中重新分离到该病毒;对其主要抗原基因σC进行测序比对和进化树分析发现,其与番鸭呼肠孤病毒基因序列的进化关系较近,同源性为89.6～98.9%。本研究证实了鹅“白点病”的病原为番鸭呼肠孤病毒,为该病的防控奠定了基础。     

一株雏鹅呼肠孤病毒的分离与鉴定

2013年福建省某鹅场发生一起以肝脏和脾脏均有灰白坏死点(肝白点)为典型病变特征的急性传染病。本研究利用10日龄非免疫番鸭胚,从病死雏鹅肝脏中分离到1株病毒。病毒分离株没有血凝活性,其ELD50为10-3.25/0.2 m L,可被鹅呼肠孤病毒高免血清特异性中和。利用鹅呼肠孤病毒特异性检测引物对FJ-06株病毒尿囊液进行RT-PCR检测,可扩增到约572 bp特异性目的条带。将RT-PCR产物进行克隆测序,Blast分析表明,克隆的基因片段为鹅呼肠孤病毒δC蛋白基因片段。结果表明成功分离到1株鹅呼肠孤病毒。     

雏半番鸭呼肠孤病毒的分离与鉴定

自以肝脏、脾脏、胰腺、肾脏表面出现多量针尖大的白色坏死点和法氏囊出血为特征的病死雏半番鸭脏器中 ,以番鸭胚分离到病毒 ,经对分离的病毒株 (FZ2 株 )进行形态学观察、理化特性测定以及血清定性中和试验等 ,发现该病毒无囊膜 ,直径为 5 5～ 70 nm;对氯仿处理敏感 ,对乙醚处理不敏感 ;无血凝活性 ;可被鸡关节炎病毒阳性血清、雏番鸭呼肠孤病毒阳性血清所中和 ,但与鸡传染性法氏囊病病毒、鸡减蛋综合征病毒无血清学关系。据此 ,确定 FZ2 株病毒为呼肠孤病毒     

种番鸭呼肠孤病毒的分离及RT-PCR鉴定

从表现为肝、脾表面坏死的240日龄种番鸭组织脏器中分离到1株病毒,暂命名为ZJ-10-06株,参照胡奇林等发表的文献进行RT-PCR[3]初步认定所分离到的毒株为呼肠孤病毒科正呼肠孤病毒属番鸭呼肠孤病毒。序列分析表明,ZJ-10-06与引起鸭脾坏死症HC/China病毒株同源率最高(95.3%),遗传进化分析可将番鸭呼肠孤病毒分成2个分支,ZJ-10-06和HC/China共处一相对独立小分支。     

绿头野鸭新型呼肠孤病毒的分离鉴定

本研究从山东临沂地区发生肝脾出血的绿头野鸭中分离到一株病毒,经RT-PCR及序列测定分析,确定为新型鸭呼肠孤病毒(命名为SD12)。该病毒可在鸡胚、鸭胚中繁殖,并导致胚体水肿、出血、死亡,同时可适应鸡胚成纤维细胞(CEF)和鸭胚成纤维细胞(DEF),细胞病变主要表现为多个细胞聚集成团,形成大的合胞体,然后细胞拉网并逐渐脱落。将该病毒分别以脑内接种、颈部皮下接种、口服三种方式接种3日龄健康雏鸭,结果颈部皮下方式雏鸭的发病率和死亡率最高,分别为30%和20%。     

Isolation of bovine coronavirus from feces and nasal swabs of calves with diarrhea.

Fecal and nasal samples were collected from 180 calves with diarrhea and 36 clinically normal co-habitants, and tested for virus using HRT-18 cell cultures derived from human rectal adenocarcinoma. A cytopathic virus was isolated from 5 fecal and 56 nasal samples obtained from diarrheic calves. All calves in which the virus was isolated from diarrheic feces were positive for virus isolation from nasal swabs. The virus was also isolated from the nasal swabs of 10 clinically normal calves that were co-habitants with diarrheic calves. Because they were morphologically similar to coronavirus, agglutinated mouse erythrocytes and serologically identical with the Nebraska calf diarrhea coronavirus, new isolates were identified as bovine coronavirus. The demonstration of viral antigens in nasal epithelial cells by a direct immunofluorescence was in close agreement with the virus isolation in HRT-18 cell cultures. This is the first report on the isolation of bovine coronavirus from newborn calves with diarrhea in Japan. The evidence that the virus was frequently isolated from nasal swabs is of great interest for understanding the pathogenesis of bovine coronavirus infection.     

牛病毒性腹泻病毒JY株分离鉴定

为了对疑似含有牛病毒性腹泻病毒(bovine viral diarrhea virus,BVDV)的种公牛精液进行检测并分离病毒,本研究采用细胞培养、免疫荧光及纳米PCR技术,对采自吉林省某牛病毒性腹泻(BVD)发病牛场中使用的种公牛精液进行检测与病毒分离。共采公牛精液8份,接种牛肾细胞系(MDBK)进行分离培养。分离得到阳性毒株为非致细胞病变(NCP)型,测得第4代病毒效价为10^6.25TCID₅₀/mL。纳米PCR检测5′-UTR和E2基因,测序后与GenBank上已发表的BVDV流行毒株核酸序列比对和进化分析。结果表明,分离毒株属于BVDV-1型,与BVDVJL株亲缘关系最近,5′-UTR核苷酸同源性为100%,E2基因核苷酸同源性为99.3%,命名为BVDVJY株。研究显示,本次采集的种公牛精液携带BVDV-1型毒株。该牛场BVD的发生疑似与种公牛精液带毒有关,对牛场BVD的防治起到警示作用。     

Isolation of bovine herpesvirus III from diarrheic feces

A herpesvirus was isolated from the feces of a cow with diarrhea. The viral isolate was identified as a herpesvirus on the basis of morphology and chloroform sensitivity. It was serologically distinct from bovine Herpesvirus I (IBR) and II (mammillitis virus) as well as equine herpesviruses and pseudorabies virus. It was serologically related to members of the bovine Herpesvirus III group.Experimentally inoculated calves developed a transient fever but no other clinical signs or lesions. The virus could be re-isolated from the calves and significant levels of virus neutralizing antibodies were present in the serum 40 days after inoculation.     

牛病毒性腹泻病毒BVDV-JL株的分离与鉴定

本研究从吉林某牛场表现严重腹泻症状濒死牛的胸腺病料样品中分离一株病毒,该病毒在MDBK细胞中盲传4代无细胞病变产生,而通过RT-PCR和间接免疫荧光试验、微量血清中和试验检测表明该分离病毒株为牛病毒性腹泻病毒(BVDV),并命名为BVDV-JL.将BVDV-JL株F4代细胞培养液(10<'7.13>TCID<,50>/...     

Viruses and virus-like particles detected during examination of feces from calves and piglets with diarrhea

A total of 763 fecal or intestinal samples from diarrheic calves and piglets were examined for viral content by immunofluorescence, electron microscopy or cell culture. Routine fluorescent antibody and cultural tests detected rotavirus (n=126), coronavirus (n=80) and bovine viral diarrhea virus (n=13). Electron microscopy detected rotaviruses (n=24) and coronaviruses (n=17) not identified by standard fluorescent antibody tests. Other viruses detected by electron microscopy included Breda virus-like particles (n=49), astroviruses (n=1), caliciviruses (n=1), rhabdoviruses (n=1), parvoviruses (n=2), enteroviruses (n=3), togavirus-like particles (n=2), and “chained” particles (n=5). Mixtures of several of the viruses were detected in a number of fecal samples.

The survey emphasized the value of electron microscopy as a broad-spectrum diagnostic tool.

     

Bile acid concentrations in serum, bile and feces of healthy calves and calves with diarrhea

On 32 calves (age 3 to 14 days) with spontaneously occurring diarrhoea, the following investigations were carried out: Regular examination of serum bile acid concentrations, collection of the entire faeces with determination of bile acid concentrations, as well as microbiological examinations. Six clinically healthy calves served as control group. In addition, bile acids in bile were determined in 16 other calves of the same age group and in 6 beef bulls. There was no significant influence of daytime or feed intake on serum bile acid concentration in diarrhoeic or healthy calves. Possibly due to the low concentrations of bile acids in the bile of young calves (4.8 +/- 3.7 mmol/l, compared to 57 +/- 13 mmol/l in the bulls), the concentrations in faeces were also rather low (control group 623 +/- 92, calves with diarrhoea 318 +/- 277, after diarrhoea. 794 +/- 935 mumol/kg). Most of it was cholic acid, whereas only traces of desoxycholic acid were found. In spite of the comparatively low concentrations of fecal bile acids, the diarrhoeic calves excreted larger amounts of bile acids than the healthy calves (12.7 +/- 13.5 vs. 1.4 +/- 0.8 mumol/kg), but this was independent of the type of enteropathogen or pathogen combinations which were detected. There were no indications for a direct influence of the diarrhoea by bile acids. However, through enteral bile acid losses, profuse diarrhoea lasting several days can cause a reduction in the total bile acid pool.     

Escherichia coli heat-stable enterotoxin in feces and intestines of calves with diarrhea

Two experiments were conducted to evaluate detection of Escherichia coli heat-stable enterotoxin (ST) in the feces of calves as a method for implicating E coli in neonatal calf diarrhea. The first experiment evaluated the use of the infant mouse test for detection of ST in the feces of calves with naturally occurring diarrhea. Simultaneous identification of bovine enteropathogenic strains of E coli (EEC) and of other infective agents implicated in neonatal calf diarrhea was attempted in these samples. The ST was detected with certainty in only 7 of 41 samples from calves less than or equal to 3 weeks old. Enteropathogenic E coli, however, was detected in 27 samples. In 23 of these 27 samples, EEC was the only recognizable diarrheagenic agent. In a small percentage of the samples, Salmonella, rotavirus, coronavirus, and cryptosporidium were recognized alone, in combination with each other, or with EEC. In the second experiment, 6 calves were fed colostrum from cows inoculated with the bovine EEC strain B44; 6 were given colostrum from cows vaccinated with non-EEC strain 28F, and 4 were given milk from nonvaccinated heifers. Two of the calves that were given colostrum from cows inoculated with strain B44 were challenge exposed with the non-EEC strain 28F. The remaining calves were challenge exposed with the EEc strain B44. Fecal samples were taken from these calves at intervals and were examined for the presence of ST and of the challenge-exposure organism. The ST was detected in approximately one half of the fecal samples obtained, and it was most often detected in the early stages of the induced diarrhea. Calves were observed to shed the challenge-exposure EEC strain for long periods in the absence of diarrhea or detectable amounts of ST in the feces. The ST was detectable in fecal samples when the diarrhea was severe and when the dry matter content of the fecal samples was low.     

一株鹅源呼肠孤病毒的分离与鉴定

一株从雏鹅肝脾脏病料中分离到的病毒，在电镜下观察到病毒粒子呈球形，无囊膜，有可见的双层衣壳结构，外壳直径75nm，内核直径50nm；经病毒分离培养、理化特性鉴定、动物回归试验、抗体检测，确定所分离到的毒株为呼肠孤病毒科正呼肠孤病毒属鹅呼肠孤病毒。