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1.
Cats have an infectious endogenous retrovirus, named RD114 virus, and there is a possibility that RD114 virus has contaminated live attenuated vaccines, for which feline cells are used as a substrate. To monitor infectious RD114 virus in vaccines for cats, we developed a LacZ marker rescue assay to detect infectious RD114 virus. Among four human cell lines examined, TE671 cells (human rhabdomyosarcoma) were most susceptible to RD114 virus and supported RD114 replication efficiently. Infection was enhanced approximately 5 times by the addition of polybrene at concentrations of 2 to 8 microg/ml in the medium during viral adsorption. A 4-hr viral adsorption period was sufficient to obtain the maximum titer. By inoculating samples into TE671 cells transduced with the lacZ marker gene, the limiting diluted sample (i.e., less than 10 infectious units) was detected at 12 days post-inoculation by the LacZ marker rescue assay. Based on the results obtained in this study, we propose a standard protocol of the LacZ marker rescue assay to detect infectious RD114 virus.  相似文献   

2.
Comparative properties of feline coronaviruses in vitro.   总被引：1，自引：0，他引：1       下载免费PDF全文
Two feline coronaviruses were characterized to determine their biological properties in vitro and their antigenic relatedness to a previously recognized feline infectious peritonitis virus and canine coronavirus. The viruses, designated WSU 79-1146 and WSU 79-1683, were shown to have comparable growth curves with the prototype feline infectious peritonitis virus. Treatment of the feline infectious peritonitis virus strains with 0.25% trypsin indicated that they were relatively resistant to proteolytic inactivation when compared with the feline enteric coronavirus strain. This observation may serve as a useful in vitro marker to distinguish closely related members of the feline coronavirus group. Plaque assay results indicated that the feline infectious peritonitis virus strains produced large homogeneous plaques in comparison to the feline enteric coronavirus strain and canine coronavirus, which showed a heterogenous plaque size distribution. No naturally temperature sensitive mutants were detected in either of the feline coronavirus populations. Both of the viruses were antigenically related to feline infectious peritonitis virus and to a lesser extent to canine coronavirus by virus neutralization.  相似文献   

3.

Background

The feline endogenous retrovirus RD114 is contained in the genome of cats. The virus may contaminate live canine vaccines based on cultured feline cells. The in vivo infectivity, acute and subacute pathogenicity, and viral proliferation of the RD114 virus were evaluated by experimental infection of dogs.

Methods

Nine specific pathogen free dogs were divided into three groups, with each group consisting of one female and two male dogs. Dogs were subcutaneously inoculated in the neck with either 1 ml RD114 stock virus (group A), inactivated RD114 virus suspension (group B), or cell culture medium (group C) as a negative control. To assess blood cell counts and biochemical properties, blood samples from each group were collected 5 days before inoculation, just prior to inoculation, and 1, 3, 7 and 10 days post-inoculation.

Result

During the experimental period of 51 days, none of the dogs inoculated with RD114 virus showed any clinical signs, significant increases in rectal temperature or abnormal blood biochemical characteristics including C-reactive protein when compared with the negative controls. We were not able to re-isolate the RD114 virus from buffy coat cells of group A dogs. Additionally, we could not detect RD114 provirus in the genomic DNA isolated from peripheral blood leukocytes, lymph node, spleen and sternal bone marrow cells.

Conclusions

Signs of RD114 virus proliferation were not found after subcutaneous infection of dogs. Although the potential risk caused by infection with RD114 virus in dogs could not be assessed in this study, we suspect that RD114 virus has little or no virulence in dogs.  相似文献   

4.
Zavala G  Cheng S 《Avian diseases》2006,50(2):209-215
Avian leukosis virus (ALV) infection in chickens is known to induce increased mortality, tumors, delayed growth, and suboptimal egg production. Countries importing specified pathogen-free eggs, vaccines, and poultry breeding stock require freedom of infection or contamination with ALV in such products among other avian pathogens. Recently, ALV was found as a contaminant in a limited number of commercial poultry vaccines, even after routine quality assurance procedures cleared the vaccines for commercialization. The contaminated vaccines were promptly withdrawn from the market, and no direct detrimental effects were reported in poultry vaccinated with such vaccines. We describe herein the characterization in vitro of the contaminant viruses. All exogenous viruses detected in four vaccine lots belong to subgroup A of ALV based on cell receptor interaction, subgroup-specific polymerase chain reaction (PCR), envelope gene sequencing, and virus neutralization. A combination of thermal treatment and serial dilutions of the contaminated vaccines facilitated detection of contaminating ALVs in cell culture coupled with antigen-capture enzyme-linked immunosorbent assay. Subgroup-specific PCR readily detected ALV-A directly in the contaminated vaccines but not in naive vaccines or cell controls. Our methods are proposed as complementary procedures to the currently required complement fixation for avian leukosis test for detection of ALV in commercial poultry vaccines.  相似文献   

5.
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6.
Viruses commonly cause gastrointestinal illnesses in dogs and cats that range in severity from mild diarrhoea to malignant neoplasia. Perpetual evolution of viruses is reflected in changing disease patterns, so that familiar viruses are sometimes discovered to cause new or unexpected diseases. For example, canine parvovirus (CPV) has regained the ability to infect felids and cause a panleucopenia-like illness. Feline panleucopenia virus (FPV) has been shown to cause fading in young kittens and has recently been implicated as a possible cause of feline idiopathic cardiomyopathy. Molecular scrutiny of viral diseases sometimes permits deeper understanding of pathogenesis and epizootiology. Feline gastrointestinal lymphomas have not, in the past, been strongly associated with retroviral infections, yet some of these tumours harbour retroviral proviruses. Feline leukaemia virus (FeLV) may play a role in lymphomagenesis, even in cats diagnosed as uninfected using conventional criteria. There is strong evidence that feline immunodeficiency virus (FIV) can also be oncogenic. The variant feline coronaviruses that cause invariably-fatal feline infectious peritonitis (FIP) arise by sporadic mutation of an ubiquitous and only mildly pathogenic feline enteric coronavirus (FECV); a finding that has substantial management implications for cat breeders and veterinarians. Conversely, canine enteric coronavirus (CECV) shows considerable genetic and antigenic diversity but causes only mild, self-limiting diarrhoea in puppies. Routine vaccination against this virus is not recommended. Although parvoviruses, coronaviruses and retroviruses are the most important known viral causes of canine and feline gastrointestinal disease, other viruses play a role. Feline and canine rotaviruses have combined with human rotaviruses to produce new, reassortant, zoonotic viruses. Some companion animal rotaviruses can infect humans directly. Undoubtedly, further viral causes of canine and feline gastrointestinal disease await discovery.  相似文献   

7.
The Oklahoma Department of Wildlife Conservation acquired 20 American river otters (Lutra canadensis) between 1984 and 1985 for reintroduction into Oklahoma waterways. In 1985, 10 otters were evaluated for serum antibody titers after vaccination with canine distemper virus, canine adenovirus type 2, canine parvovirus (CPV), feline panleukopenia virus (FPV), feline rhinotracheitis virus (FRV), and feline calicivirus. Prevaccination serum-virus neutralization (SVN) antibody to feline rhinotracheitis virus was found in 2 otters and to feline calicivirus in 1 otter. Using an indirect fluorescent antibody (IFA) assay, prevaccination antibody to CPV and FPV was found in 2 otters. A significant increase in SVN antibody titers was found after vaccination of otters with canine adenovirus type 2 (6 of 8 animals) and feline calicivirus (1 of 8 animals). One of 8 otters developed significant antibody titers to CPV and FPV, as measured by IFA assay. Otters did not develop SVN antibody titers to canine distemper virus after vaccination. Antigens of feline leukemia virus, using ELISA, or antibodies to feline infectious peritonitis, using IFA assay, were not found in the 20 otters.  相似文献   

8.
Mink virus enteritis, feline panleukopenia and canine parvovirus-2 were inoculated separately into groups of raccoon, mink, red fox and striped skunk. Raccoons were highly susceptible to mink virus enteritis and feline panleukopenia, with animals developing clinical illness, and several dying within six to ten days of inoculation with lesions typical of parvovirus infection. Both viruses were shed in high titre in the feces of infected raccoons, and high antibody titres were stimulated. Raccoons inoculated with canine parvovirus-2 showed no signs; shedding of virus was sporadic though moderate titres of antibody developed. Mink inoculated with mink virus enteritis and feline panleukopenia developed signs and lesions of early parvovirus infection. No signs or significant lesions followed canine parvovirus-2 inoculation. Shedding of virus was heavy (mink virus enteritis) or sporadic (feline panleukopenia and canine parvovirus-2), though good serological responses were elicited to all three viruses. Red fox showed no signs of infection, shed all three viruses only sporadically, and the serological response was strong only to feline panleukopenia. Skunks developed low antibody titres, but no signs, and did not shed virus. Antibody to parvovirus was found in 79.2% of 144 wild red foxes; 22.3% of 112 wild raccoons; 1.3% of 157 wild skunks and 6/7 coyotes in southern Ontario. The likely significance of these viruses to wild and captive individuals and populations of these carnivores is discussed.  相似文献   

9.
A cell-line, designated LSA-1, was derived from a thymic lymphosarcoma that occurred in a cat with experimentally induced feline leukemia virus (FeLV) infection. LSA-1 cells possessed surface receptors and antigens of normal T-lymphocytes, but were unresponsive to interleukin-2 stimulation. The LSA cell-line was found to constitutively produce and release an interferon into the culture supernatants. Production of this interferon was enhanced in certain clones of the original LSA-1 cell lines. The interferon produced by LSA-1 cells and some of its clones was compared to the standard alpha, beta, and gamma interferons of cats. Unlike alpha and beta interferons, which were acid, SDS, and heat stable, LSA interferon was acid labile and SDS and heat stable. In comparison, standard feline gamma interferon was acid, SDS, and heat labile. LSA interferon had a molecular weight of 20,000 daltons, compared to 17-19,000 daltons for gamma, 19-25,000 for beta, and 25-45,000 daltons for alpha interferons. Standard feline interferons were active only on cat cell lines, with the exceptions of alpha interferon, which also reacted with MDCK canine cells. LSA interferon resembled the standard feline alpha interferon because it also reacted with feline and canine cells. It was concluded that LSA interferon was an atypical acid labile alpha interferon, resembling in this respect the abnormal alpha interferon seen in humans with AIDS and SLE, and mice with retrovirus infections. LSA-1 cells produced high levels of FeLV structural proteins but very little infectious virus. This effect was due to endogenously produced interferon; LSA cell clones that were selected for low interferon production produced much higher levels of infectious FeLV than parent cells or clones selected for high interferon production. Cat cells pretreated with LSA or with standard feline alpha and beta interferons, and then infected with FeLV, produced high levels of FeLV proteins but very little infectious virus.  相似文献   

10.
Unlike the original canine parvovirus type 2 (CPV-2), CPV-2 variants have gained the ability to replicate in vivo in cats but there is limited information on the disease patterns induced by these variants in the feline host. During 2008, two distinct cases of parvoviral infection were diagnosed in our laboratories. A CPV-2a variant was identified in a 3-month-old Persian kitten displaying clinical sign of feline panleukopenia (FPL) (acute gastroenteritis and marked leukopenia) and oral ulcerations, that died eight days after the onset of the disease. Two pups living in the same pet shop as the cat were found to shed a CPV-2a strain genetically identical to the feline virus and were likely the source of infection. Also, non-fatal infection by a CPV-2c strain occurred in a 2.5-month-old European shorthair kitten displaying non-haemorrhagic diarrhoea and normal white blood cell counts. By sequence analysis of the major capsid protein (VP2) gene, the feline CPV-2c strain showed 100% identity to a recent canine type-2c isolate. Both kittens had been administered multivalent vaccines against common feline pathogens including FPL virus. Whether and to which extent the FPL vaccines can protect cats adequately from the antigenic variants of CPV-2 should be assessed.  相似文献   

11.
Fourteen specific-pathogen-free cats were inoculated with a putative env gene recombinant feline retrovirus, PR8. An isolate of the Rickard strain of feline leukemia virus (FeLV-R), PR8, has the properties of both an exogenous (FeLV-R) and an endogenous (xenotropic) feline retrovirus (RD-114). Twelve of the PR8-inoculated cats developed viremia; 2 of the 12 cats developed eosinophilia, with 1 being diagnosed with eosinophilic leukemia and the other with extreme eosinophilic hyperplasia. Eosinophilic leukemia is rare in cats and has not previously been associated with retroviral infection. Changes in the viral envelope properties may have altered the pathogenicity of the exogenous virus to cause this rare form of leukemia.  相似文献   

12.
Molecular and structural basis of the evolution of parvovirus tropism.   总被引：1，自引：0，他引：1  
Parvoviruses have small genomes and, consequently, are highly dependent on their host for various functions in their reproduction. Since these viruses generally use ubiquitous receptors, restrictions are usually intracellularly regulated. A lack of mitosis, and hence absence of enzymes required for DNA replication, is a powerful block of virus infection. Allotropic determinants have been identified for several parvoviruses: porcine parvovirus, canine parvovirus (CPV), feline parvovirus (feline panleukopenia virus), minute virus of mice, Aleutian disease virus, and GmDNV (an insect parvovirus). Invariably, these identifications involved the use of infectious clones of these viruses and the exchange of restriction fragments to create chimeric viruses, of which the resulting phenotype was then established by transfection in appropriate cell lines. The tropism of these viruses was found to be governed by minimal changes in the sequence of the capsid proteins and, often, only 2 or 3 critical amino acids are responsible for a given tropism. These amino acids are usually located on the outside of the capsid near or on the spike of the threefold axis for the vertebrate parvoviruses and on loops 2 or 3 for the insect parvoviruses. This tropism is not mediated via specific cellular receptors but by interactions with intracellular factors. The nature of these factors is unknown but most data point to a stage beyond the conversion of the single-stranded DNA genome by host cell DNA polymerase into monomeric duplex intermediates of the replicative form. The sudden and devastating emergence of mink enteritis virus (MEV) and CPV in the last 50 years, and the possibility of more future outbreaks, demonstrates the importance of understanding parvovirus tropism.  相似文献   

13.
The efficacy of two commercial feline vaccines was determined by challenging vaccinated and unvaccinated cats sequentially with a virulent feline calicivirus and rhinotracheitis virus. Serological responses to these viruses as well as to panleuk openia virus were also measured. Results show significant protection and satisfactory serological responses are conferred by both vaccines. One vaccine showed significant superiority in protection against feline viral rhinotracheitis.  相似文献   

14.
In our studies aimed at assessing the minimum duration of vaccinal immunity (DOI), approximately 1000 dogs have been vaccinated with products from all the major US veterinary biological companies. The DOI for the various products is determined by antibody titers for all dogs and, by challenge studies in selected groups of dogs. Recently, all major companies that make canine vaccines for the U.S. market have completed their own studies; published data show a 3 years or longer minimum DOI for the canine core products, canine distemper virus (CDV), canine parvovirus type 2 (CPV-2), and canine adenovirus-2 (CAV-2). Studies with feline core vaccines - feline parvovirus (FPV), calicivirus (FCV) and herpes virus type I (FHV-1) have shown a minimum DOI of greater than 3 years. Based on these results, the current canine and feline guidelines (which recommend that the last dose of core vaccines be given to puppies and kittens > or =12 weeks of age or older, then revaccination again at 1 year, then not more often than every 3 years) should provide a level of protection equal to that achieved by annual revaccination. In contrast, the non-core canine and feline vaccines, perhaps with the exception of feline leukaemia vaccines, provide immunity for < or =1 year. In general the effectiveness of the non-core products is less than the core products. Thus, when required, non-core vaccines should be administered yearly, or even more frequently.  相似文献   

15.
There is growing interest in utilizing replicating oncolytic viruses as cancer therapeutics agents. The effectiveness of myxoma virus-induced oncolysis was evaluated in two feline cancer cell cultures. Although myxoma virus is a rabbit-specific pathogen, protein expression driven by myxoma virus and production of infectious viral particles were detected. Cell death occurred in primary feline cancer cells within 48 h of inoculation with myxoma virus. Future studies to determine if other feline neoplasms are susceptible to myxoma virus infection are warranted.  相似文献   

16.
Utilizing specific immunofluorescence as a viral indicator for a cell culture serum-neutralization system, the authors were able to demonstrate a relationship between specific antibody titer and susceptibility of felines to feline panleucopenia virus.

This correlation was established by comparing prechallenge serum-neutralization titers to the clinical response of felines challenged with feline panleucopenia virus. The serological and clinical response of felines inoculated with commercial vaccines or related viruses was also studied.

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17.
The virus neutralization (VN) antibody titers of serum samples from 18 individuals representing 8 carnivore species vaccinated with commercial polyvalent vaccines optimized for domestic cats containing inactivated feline panleukopenia virus (FPLV) were evaluated against canine parvovirus type 2 (CPV2). In addition, the titers among 5 individuals from 4 carnivore were evaluated against antigenic variants of feline parvoviruses; FPLV, CPV2, CPV2a, CPV2b, CPV2c, mink enteritis virus type 1 (MEV1) and MEV2. The polyvalent vaccines induced cross-reactive VN titers against antigenic variants of feline parvoviruses in nondomestic felids. However, we observed very low cross-reactive VN antibody in lions and Siberian tigers, therefore we should pay attention to CPV infections in these animals even if they were vaccinated with inactivated FPLV vaccines.  相似文献   

18.
为了比较冠状病毒基因相关性,获得特异基因克隆制备冠状病毒基因芯片,根据发布的基因序列,每种病毒设计4~17对引物,利用火鸡冠状病毒(TCV)原毒和蔗糖密度梯度离心纯化浓缩的犬冠状病毒(CCV)、猫冠状病毒(FCV)、猫传染性腹膜炎病毒(FIPV)、猪传染性胃肠炎病毒(TGEV)、猪呼吸道冠状病毒(PRCV)、牛冠状病毒(BCV)细胞毒,提取总RNA并反转录和PCR扩增。回收PCR产物连接pGEM-T-easy载体并转化大肠杆菌TGI,经PCR鉴定后测序。将所有基因片段的核苷酸序列和推导的氨基酸序列,分别与GenBank有关病毒相关基因片段的核苷酸序列进行分析比较,确定它们的同源性。通过对不同冠状病毒不同基因片段的克隆和测序,发现同一群冠状病毒核苷酸序列间具有较高的同源性。  相似文献   

19.
A parvovirus of canine origin, cultured in a feline kidney cell line, was inactivated with formalin. Three pilot serials were produced and three forms of finished vaccine (nonadjuvanted, single adjuvanted and double adjuvanted) were tested in vaccination and challenge trials. A comparison was also made with two inactivated feline panleukopenia virus vaccines, one of which has official approval for use in dogs. The inactivated canine vaccine in nonadjuvanted, adjuvanted or double adjuvanted form was immunogenic in 20 of 20 vaccinated dogs. The double adjuvanted vaccine is selected as the one of choice on the basis of best and most persistent seriological response.  相似文献   

20.
Objective – The aim of this review is to describe and evaluate both conventional and molecular diagnostic testing utilized in dogs and cats with acute neurologic diseases. Various types of polymerase chain reaction (PCR) are explored along with novel molecular diagnostic testing that ultimately may prove useful in the critical care setting. Data Sources – PUBMED was searched to obtain relevant references material using keywords: ‘canine OR feline meningitis AND meningoencephalitis,’‘feline infectious peritonitis,’‘canine distemper,’‘canine OR feline AND toxoplasma,’‘canine neospora,’‘canine OR feline AND rickettsia,’‘granulomatous meningoencephalitis,’‘steroid responsive meningitis arteritis,’‘necrotizing encephalitis,’‘novel neurodiagnostics,’‘canine OR feline AND CNS borrelia,’‘canine OR feline AND CNS bartonella,’‘canine OR feline AND CNS fungal,’‘nested OR multiplex OR degenerate OR consensus OR CODEHOP AND PCR.’ Research findings from the authors' laboratory and current veterinary textbooks also were utilized. Human Data Synthesis – Molecular diagnostic testing including conventional, real‐time, and consensus and degenerate PCR and microarray analysis are utilized routinely for the antemortem diagnosis of infectious meningoencephalitis (ME) in humans. Recently, PCR using consensus degenerate hybrid primers (CODEHOP) has been used to identify and characterize a number of novel human viruses. Veterinary Data Synthesis – Molecular diagnostic testing such as conventional and real‐time PCR aid in the diagnosis of several important central nervous system infectious agents including canine distemper virus, Toxoplasma gondii, Neospora caninum, rickettsial species, and others. Recently, broadly reactive consensus and degenerate PCR reactions have been applied to canine ME including assays for rickettsial organisms, Borrelia spp. and Bartonella spp., and various viral families. Conclusions – In the acute neurologic patient, there are several key infectious diseases that can be pursued by a combination of conventional and molecular diagnostic testing. It is important that the clinician understands the utility, as well as the limitations, of the various neurodiagnostic tests that are available.  相似文献   

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