Virus and virus-like particles in the faeces of cats with and without diarrhoea

Negative staining electron microscopy was used to identify viruses in 166 normal and 62 diarrhoeal faecal samples from 208 cats admitted to an animal shelter during a 16-month period (March 1984 to June 1985). On the basis of size and shape 7 distinct viral types were detected: 24 nm parvovirus-like particles, 30 nm astrovirus, 30 nm picornavirus-like particles, reovirus, rotavirus, coronavirus and a 75 nm "togavirus-like" particle. The incidence of these particles in the 208 cats was 11%, 7%, 6%, 0.4%, 5%, 1% and 1% respectively. Virus isolation studies using 40 of the faecal samples succeeded in isolating reovirus 1 in 2 cases. Immune electron microscope studies demonstrated the presence of antibody in a human serum to cat astrovirus, but failed to clarify the identity of the parvovirus-like particles and picornavirus-like particles, other than showing that some of the parvovirus-like particles were not related to feline panleukopenia virus. It was found that parvovirus-like particles, astrovirus, picornavirus-like particles, reovirus and rotavirus could be excreted by cats with normal faeces as well as cats with diarrhoeal faeces. Parvovirus-like particles, astrovirus, picornavirus-like particles and rotavirus could be excreted in high concentration in normal faeces. There was no simple relationship between age and diarrhoea in the population of cats studied. Age was not a critical factor in the excretion of parvovirus-like particles, astrovirus, picornavirus-like particles and rotavirus. The incidence of diarrhoea was not clearly associated with the seasons.     

Epizootic diarrhoea of adult cattle associated with a coronavirus-like agent

An epizootic of acute diarrhoea of adult cattle occured in Japan during the winter of 1976 to 1977. A majority of adult cattle clinically diagnosed as having the disease, showed a significant rises in antibody titres to bovine coronavirus, whereas only a smal; minority showed serological evidence of recent infection with calf rotavirus, bovine adenovirus type 7, parainfluenza virus type 3, or bovine viral diarrhoea-mucosal disease virus. A coronavirus-like agent was detected by electron-microscopy in faecal material from a cow with diarrhoea, and was subsequently isolated in primary bovine kidney cell cultures.     

Research on antibodies against BHV-1, BHV-2, BHV-4, BVD-MD virus, bovine adenovirus A and B, rotavirus and coronavirus in cattle in western Zaire: complementary results

Two-hundred bovine sera from western Zaire were screened for antibodies to 8 viruses: BHV-1, BHV-2, BHV-4, BVD-MD virus, bovine adenovirus A and B, bovine rotavirus and bovine coronavirus. Positive sera were found to all these viruses. For animals whose origin was undoubted, the main features were the high prevalence of infections by rotavirus and BHV-4 and the low prevalence of infections by coronavirus and BVD-MD virus.     

Enteric viral infections of turkey poults: incidence of infection

Four flocks from one commercial market-turkey operation in Ohio were monitored for the presence of enteric viruses. Each flock was sampled at intervals from placement until at least 7 weeks of age; sampling was more frequent in the first 4 weeks of life. The earliest infections detected were astrovirus infections or combination infections of astrovirus and rotavirus-like virus (RVLV) or astrovirus and rotavirus. During the first 4 weeks of life, astrovirus was the most frequently detected virus, followed by RVLV, then rotavirus. These viruses were seldom detected beyond 4 weeks of age. In three of the four flocks, no viruses were detected in samples collected before 6 days of age; in one flock, however, rotavirus and astrovirus were identified from samples collected at 3 days of age. Experimental infection of specific-pathogen-free poults with astrovirus and RVLV produced enteric diseases in poults and demonstrated that astrovirus was shed into the intestinal tract before RVLV. Poults experimentally infected with astrovirus and RVLV displayed clinical signs of diarrhea and upon necropsy exhibited dilated ceca, frothy gaseous intestinal contents, and loss of intestinal tone.     

规模化奶牛场犊牛腹泻的病原检测与分析报告

为了调查某规模化奶牛场犊牛腹泻的发病原因,试验采用血清抗体检测、细菌分离培养、寄生虫卵镜检和病毒核酸检测方法对腹泻犊牛的血样和粪便进行了检查。结果表明,该奶牛场牛病毒性腹泻/黏膜病病毒抗体阳性率为65.00%,牛轮状病毒抗体阳性率25.00%,牛冠状病毒抗体阳性率15.00%;分离到1 株结肠弯曲杆菌和1 株空肠弯曲杆菌;所检腹泻犊牛粪便和血液样品中,4 份粪便样品和1 份血液样品检出牛冠状病毒,2 份粪便样品检出轮状病毒,1 份粪便样品和1 份血液样品检出牛病毒性腹泻/黏膜病病毒,同一份粪便样品中同时检出牛病毒性腹泻/黏膜病病毒和牛冠状病毒;通过镜检,球虫卵囊检出率77.78%,在1 份粪样中发现蛔虫卵,2 份粪样中发现其他线虫卵。该牛场流行性腹泻的原因可能为夏季高温潮湿引起犊牛免疫力下降导致的多病原体感染。     

A new polyvalent vaccine against enteral infections in newborn calves

The most frequent microbial causative agents of massive diarrheas in new-born calves kept on large cattle farms in the CSSR are rotaviruses, coronaviruses and enterotoxigenic strains of E. coli, manifesting themselves as complicated virus-bacterial infections. An inactivated polyvalent adjuvant vaccine has been developed for the prevention and specific prophylaxis of these enteral infections; the vaccine contains bovine rotavirus, bovine coronavirus and three enterotoxigenic serotypes of E. coli with protective antigen K 99. The rotavirus and coronavirus are propagated on the stable cellular line MDBK and inactivated with 0.2% formalin, the Escherichia strains are submersed in the MINCA culture medium during their cultivation and inactivated with 0.5% formalin. The vaccine was prepared as a blend of the same amounts of rotavirus and coronavirus and of such an amount of bacterin so that 1 ml of the vaccine will contain 10(9) bacteria. One part of oil adjuvant was added to five parts of the virus-bacterial blend and the blend was homogenized in the Ultraturax apparatus. The vaccine is to be used for immunization of pregnant cows and heifers; in these animals it induces the production of specific antibodies to all antigens contained in the vaccine. Its immunogenic effects were checked in 32 calves and 38 cows in the herds with the occurrence of diarrheas caused by both enteropathogenic viruses and enterotoxigenic escherichia. It was demonstrated that the inactivation did not influence in either of the viruses the process of inducing the production of specific antibodies, and the antibody response of the calves and heifers after application of 2 ml of complete inactivated vaccine was equally strong as after application of live vaccine containing only rotavirus and coronavirus. The level of the rotavirus antibodies increased on the average 30 times and 200 times, coronavirus antibodies twice and four times. The antibody response to coronavirus was negatively influenced by the relatively high levels of antibodies before vaccination. The antibody response to antigen K 99 was expressive in all cases.     

Rotavirus and coronavirus associated diarrohoea in calves

A virological survey was carried out on 150 calf faeces from 30 central North Island properties, utilising electron miscroscopic examination of ultracentrifuged faecal pellets. Rotaviruses were detected on three farms, and coronavirus-like particles on two farms.

In the same area, three other properties with past histories of rotavirus infection were also studied. Weekly examination of faeces from 10 calves from each property over a period of 5 weeks demonstrated that rotavirus excretion commenced at the same time as the onset of outbreaks of diarrhoea. On two of these rotavirus-positive farms, coronaviruses were also detected. At one farm, this coincided with rotavirus excretion and diarrhoea, and was associated with a more severe clinical disease but, on the other property, the coronavirus was unassociated with clinical disease. A similar study, carried out on a further property with a past history of coronavirus infection, showed that coronavirus excretion commenced simultaneously with the onset of an outbreak of diarrhoea. The virus was, however, detected in small numbers in 1 of 10 calves only.

The results of the survey, coupled with previously gathered data, indicate that both viruses may be widespread in the cattle population. On some properties, rotavirus had a clear association with diarrhoea, but the relationship of coronavirus to diarrhoea was less well-established.     

Viruses and virus-like particles in the faeces of dogs with and without diarrhoea

Negative staining electron microscopy was used to identify viruses in 157 normal and 29 diarrhoeal faecal samples collected from 156 dogs admitted to an animal shelter during an 8 month period (March to October) in 1982. Seven distinct viral types were detected: 21-26 nm parvovirus-like particles, 28-31 nm astrovirus-like particles, a previously undescribed 34-35 nm "round" virus particle, coronavirus, coronavirus-like particles ( CVLP ), rotavirus and papova-like virus. Parvovirus-like particles alone were detected in 14 diarrhoeal and 50 normal faeces, astrovirus-like particles in 3 normal faeces, "round" viruses in 4 normal faeces, coronavirus in 2 diarrhoeal and 5 normal faeces, CVLP in one diarrhoeal and one normal faeces, rotavirus in 2 normal faeces, papova-like virus in one normal faeces, both parvovirus-like particles and coronavirus in 2 diarrhoeal and 2 normal faeces, parvovirus-like particles and rotavirus in one normal faeces and parvovirus-like and papova-like virus in one normal faeces. The significance of these findings in canine and human disease is discussed.     

检测牛5种腹泻病毒的多重RT-PCR方法的建立及应用

牛A群轮状病毒(BRVA)、牛冠状病毒(BCoV)、牛病毒性腹泻病毒(BVDV)、牛诺瓦病毒(BNoV)和牛纽布病毒(BNeV)是引起犊牛腹泻的常见病毒,且临床上多存在混合感染的情况.本试验的目的 是建立可以同时检测上述5种病毒的多重PCR方法.通过设计引物,优化反应体系和条件,成功建立了可同时检测BRVA、BCoV、...     

Prevalence of respiratory pathogens in diseased, non-vaccinated, routinely medicated veal calves

The prevalence of respiratory pathogens in diseased veal calves was determined in 24 respiratory disease outbreaks in 15 herds in Belgium. Bacteria were cultured from nasopharyngeal swabs and seroconversion against viruses and Mycoplasma bovis was determined on paired sera. At the individual calf level, Mycoplasma species, Mannheimia haemolytica and Pasteurella multocida, were isolated from 70.5 per cent, 21.5 per cent and 26.0 per cent of swabs, respectively. At the herd level, the presence of M bovis could be confirmed in 84.6 per cent of the herds examined. Seroconversion against bovine viral diarrhoea virus (BVDV) was present in 71.4 per cent of herds, parainfluenzavirus type 3 in 53.3 per cent, bovine respiratory syncytial virus in 40.0 per cent, bovine adenovirus type 3 in 46.7 per cent, bovine coronavirus in 30.0 per cent, and bovine herpesvirus type 1 in 26.7 per cent. At postmortem examination, Mycoplasma species could be cultured from 61.9 per cent of pneumonic lungs (n=21). Sixty per cent of calves tested were positive for BVDV (n=20), and 20.0 per cent were positive for bovine respiratory syncytial virus (n=16).     

Detection of bovine coronavirus and type A rotavirus in neonatal calf diarrhea and winter dysentery of cattle in Quebec: evaluation of three diagnostic methods.

The use of direct electron microscopy, enzyme-linked immunosorbent assay, and protein A-gold immunoelectron microscopy for the identification of bovine coronavirus and type A rotavirus were examined. Two hundred and forty-nine samples from diarrheic calves and winter dysenteric cattle from seven geographic areas in Quebec were examined for the presence of viruses by direct electron microscopy of negatively stained preparations. In addition, all the samples were analyzed by enzyme-linked immunosorbent assay, and a random selection of 47 samples were also analyzed by protein A-gold immunoelectron microscopy. Thirty-nine percent of samples examined by direct electron microscopy contained viral particles; bovine coronavirus and type A rotavirus were the most common viruses involved. Overall agreement between any two of the methods used compared favorably with results obtained by others using similar methods. The presence of coronavirus and rotavirus in fecal samples obtained from neonatal calves and the presence of coronavirus in samples from winter dysenteric adult cattle suggested their etiological roles in the respective diseases. Furthermore, results from protein A-gold immunoelectron microscopy of coronavirus-like particles implied that a different coronavirus or some other viruses might be involved in these diseases. Finally, the efficiency of direct electron microscopy, enzyme-linked immunosorbent assay and protein A-gold immunoelectron microscopy as diagnostic tools is discussed.     

A seroepidemiological study of the importance in cow-calf pairs of respiratory and enteric viruses in beef operations from northwestern Quebec.

Serum antibody analyses for bovine herpesvirus type 1 (BHV-1), bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), bovine coronavirus (BCV), and bovine rotavirus (BRV) were performed on 527 randomly selected cows, before calving, and on 407 three-week-old calves. In cows and calves, BCV and BRV were the most seroprevalent viruses (80% to 100% according to virus and vaccination status). Bovine respiratory syncytial virus was the least seroprevalent in the cows, independent of the vaccination status. In nonvaccinated cows the seroprevalence to BRSV was 36.7%, and 53.5% in cows vaccinated less than two weeks prior to collecting blood, and 67.6% in cows vaccinated two weeks or more prior to blood collection. In their calves, BHV-1 was the least seroprevalent, independent of the vaccination status. The serological status and antibody titers in calves were generally associated with those of the dam. The occurrence of respiratory diseases in the calves was associated with cow and calf serological profiles (BHV-1, BRSV and BCV in the nonvaccinated group, BHV-1, BVDV and BCV in the vaccinated group). The occurrence of diarrhea was not associated with cow and calf serological profiles but was negatively associated with high level calf serum IgG in the nonvaccinated group (odds ratio = 0.73). Bovine coronavirus and BRV were shed by 1.4% and 4.9% of calves in the nonvaccinated group, and by 0% and 9.9% of calves in the vaccinated group, respectively. Bovine rotavirus shedding was associated with fecal diarrheic consistency at the moment of fecal sampling but not with previous occurrence of diarrhea.     

Prevalence of rotavirus and coronavirus antigens in the feces of normal cows.

The prevalence of rotavirus and coronavirus shedding by adult cows was investigated using capture enzyme-linked immunosorbent assays. Fecal samples from 121 cows in a single herd were tested for the presence of rotavirus and coronavirus, either free or complexed with immunoglobulin. Free rotavirus was not detected in any samples while rotavirus-immunoglobulin complexes were detected in 53 of 121 (44%) samples tested. In contrast, free coronavirus was detected in six (5%) samples and coronavirus-immunoglobulin complexes were detected in 85 (70%) of the samples tested. Thus it appears that subclinical infection of cows by either of these viruses is common, possibly providing a source for infection of the neonate. These assays may therefore provide important information regarding the epidemiology of enteric virus infections and suggest means of improving management to prevent epidemics of neonatal diarrhea.     

Microbiology of calf diarrhoea in southern Britain

Faeces samples from calves with diarrhoea in 45 outbreaks were examined for six enteropathogens. Rotavirus and coronavirus were detected by ELISA in 208 (42 per cent) and 69 (14 per cent) of 490 calves respectively; calici-like viruses were detected by electron microscopy in 14 of 132 calves (11 per cent). Cryptosporidium were detected in 106 of 465 (23 per cent), Salmonella species in 58 of 490 (12 per cent) and enterotoxigenic Escherichia coli bearing the K99 adhesin (K99+ E coli) in nine of 310 calves (3 per cent). In the faeces of 20 per cent of calves with diarrhoea more than one enteropathogen was detected; in 31 per cent no enteropathogen was found. Faces samples from 385 healthy calves in the same outbreaks were also examined. There was a significant statistical association of disease with the presence of rotavirus, coronavirus, Cryptosporidium and Salmonella species (P less than 0.001). Healthy calves were not examined for calici-like viruses and the association of K99+ E coli with disease was not analysed because there were too few positive samples. Rotavirus infections were more common in dairy herds and single suckler beef herds whereas Salmonella infections were more often found in calf rearing units. Cryptosporidium were more common in single and multiple suckler beef herds. K99+ E coli were found in one dairy herd and one multiple suckler beef herd both with unhygienic calving accommodation. Variations in coronavirus detection among different farm types were not statistically significant. In this survey rotavirus was the most commonly detected agent in calf diarrhoea and Cryptosporidium were found in approximately one quarter of affected calves. Infection with Salmonella species was widespread, but K99+ E coli infections were less common in the United Kingdom than in other countries.     

一例冠状病毒、轮状病毒混合感染引起犊牛腹泻的诊治

2022年3月,河南省某规模化奶牛养殖场发生一起新生犊牛腹泻病例,在流行病学调查、临床症状观察、病理剖检的基础上,采集6头腹泻犊牛的新鲜粪便进行了寄生虫卵检查、小球隐孢子虫、牛轮状病毒、冠状病毒、大肠杆菌K99抗体检测,血液样品进行了牛病毒性腹泻病毒抗原检测,组织样品进行了细菌分离。结果表明牛轮状病毒抗原6头阳性,阳性率100%;冠状病毒抗原4头阳性、2头阴性,阳性率66.7%;其他病原均为阴性。根据临床症状、病理变化和实验室检测结果,确诊该病例为牛冠状病毒和轮状病毒混合感染引起的犊牛腹泻。根据诊断结果,采取了改善饲养管理、补液、收敛、止泻等综合性防治措施,疫情得到了有效的控制,为临床防治犊牛腹泻提供了参考。     

Studies with an unclassified virus isolated from diarrheic calves

A transmissible agent (Breda agent) was isolated from a calf with diarrhea and shown to be infectious by inoculation orally into gnotobiotic and conventionally reared calves. The “Breda” agent had the morphology of a virus and possessed a hemagglutinin. Antigenic studies showed the virus to be antigenically different from bovine coronavirus, parainfluenza 3 virus, bovine rotavirus, bovine parvovirus and bovine pestivirus (BVD). Attempts to culture the virus in cell or organ cultures or in embryonated eggs, were unsuccessful. The virus was either spherical or kidney shaped, with 7–9 nm peplomers on the surface. A few particles possessed coronavirus processes of 17–20 nm, but these were arranged irregularly and were thought to be tissue debris. Three out of eight experimental calves developed severe diarrhea and the lesions in the small and large intestines were similar to those reported for coronavirus. The virus replicated in the jejunal and ileal regions of the small intestine and in the spiral colon, as judged by immunofluorescence. The virus multiplied in all experimental calves and was excreted in the feces; excretion correlating with the onset of diarrhea or a change in the appearance of the feces. There was little or no malabsorption measured by the uptake of D-xylose and the fact that infection of both the crypt and villus epithelial cells was observed, suggests that the pathogenesis may be different from rotavirus and coronavirus. Fourteen of fortyseven calves in the outbreak were infected with the virus, virus was not identified in other farm outbreaks of the disease.     

Viral agents associated with outbreaks of diarrhea in turkey flocks in Quebec.

The relative importance of various enteric viruses associated with diarrhea of turkey poults was investigated by an evaluation of specimens received since 1982. Specimens originated from one to eight week old turkey poults, with mild to severe diarrhea, from 114 flocks in 42 commercial operations located in southern Quebec. The acute phase of enteritis occurred usually in poults between two and four weeks of age. Clarified intestinal contents were examined by direct electron microscopy and enzyme immunoassays. Enzyme-linked immunosorbent assays were performed with antisera to bovine rotavirus group antigen, avian reovirus types 1 to 5, and the prototype strain of the turkey enteric coronavirus. The presence of viruses could be demonstrated by electron microscopy in 55.3% of the specimens, and at least five different viruses were incriminated either alone or in combination. The coronavirus was by far the most common enteric virus with a prevalence of 47.5%. By enzyme-linked immunosorbent assay, rotavirus, reovirus and turkey coronavirus were detected in 14.5%, 18.1% and 61.4% of the specimens, respectively. By electron microscopy, 56.6% of these cases were positive for at least one virus.