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1.
The presence and numbers of bovine herpesvirus 4 (BoHV-4) infected CD11b+ leukocytes were investigated during experimental infections of New Zealand White rabbits by Fluorescence Activated Cell Sorter (FACS) analysis. Peripheral blood leukocytes (PBL) were collected every second day, and the cells were stained with phycoerythrin-labelled CD11b-specific mouse monoclonal antibody and fluorescein-conjugated bovine herpesvirus 4-specific mouse monoclonal antibody. The numbers of double-stained cells from PBLs of the control and inoculated groups were measured and compared in FACSTREK analyser. Double-stained cells were detected in the virus-inoculated group on postinoculation days (PID) 2-5 and 9-12. The results indicated that CD11b+ PBLs were permissive for BoHV-4 infection, and are probably the main reservoir of the virus during the latent period. The data did not indicate production of infectious viral particles, but virus-specific proteins were expressed on the surface of CD11b+ cells. The two waves of double-stained cells gave similar results to the PCR assays from serum samples, which showed the presence of viral DNA in the serum on the same days when virus-infected CD11b cells were also present. Productive BoHV-4 infection of mast cells or undifferentiated leukocytes in the bone marrow and the antiviral immune response might be responsible for this periodic appearance of the virus in CD11b+ PBLs and in the serum. The paper provides evidence that CD11b+ PBLs are the main target cell populations in the blood for BoHV-4.  相似文献   

2.
Uteri from 31 infertile cattle were examined for the presence of bovine herpesvirus 4 (BoHV-4) by nested polymerase chain reaction (PCR). Samples were also tested for bacteria, including chlamydiae and Mycoplasma bovis. BoHV-4 was detected by PCR in 27/31 (87.1%) samples, but the presence and amount of viral DNA was not correlated with histological and bacteriological findings. Arcanobacterium pyogenes, Histophilus somni and Pasteurella multocida were isolated from five cows with endometritis. Chlamydiae were detected in four cases (12.9%), but only two of these had endometritis. The study does not support a role for BoHV-4 as primary agent in bovine endometritis.  相似文献   

3.
AIM: To detect the presence of bovine herpesvirus (BoHV) type 4 in New Zealand dairy cows with clinical metritis.

METHODS: Serum samples taken from 92 dairy cows with clinical metritis, each from a different farm, were tested for the presence of antibodies against BoHV-4 using a commercially available, indirect ELISA. Peripheral blood mononuclear cells (PBMC) were collected from 10 BoHV-4 seropositive cows, and PBMC were examined by a pan-herpesvirus nested PCR to detect herpesvirus. PCR products were sequenced directly and a proportion of the PCR products were cloned and sequenced to identify the virus present.

RESULTS: Antibodies to BoHV-4 were detected in 23/92 (25%) serum samples. The pan-herpesvirus PCR was positive in 8/10 PBMC samples. Cloning and sequencing identified that all of the eight PCR-positive PBMC contained bovine lymphotropic herpesvirus (BLHV); no BoHV-4 DNA was detected.

CONCLUSIONS: This study reports the finding of the presence of apparent antibodies to BoHV-4, and BLHV DNA in New Zealand dairy cows affected by metritis.

CLINICAL RELEVANCE: Bovine herpesvirus type 4 and BLHV are reported to have the potential to cause reproduction failure in cows. This is the first report of apparent BoHV-4 antibodies, and BLHV in New Zealand. The importance and epidemiology of these viruses in cattle in New Zealand requires further investigation.  相似文献   

4.
Rabies and herpetic encephalitis are the main viral infections in bovines with neurological symptoms. Bovine rabies has a high prevalence in Central and South America, while bovine encephalitis associated with herpesvirus is especially important in South America. Viral isolation is the classical way to confirm herpesvirus infection, but molecular evidence of the presence of the virus in affected animals is gaining importance in the diagnosis of the disease in the laboratory. This study investigated the presence of herpesvirus type 1 and 5 (BoHV-1 and BoHV-5) in 182 encephalon of rabies-suspected cattle in Rio Grande do Sul state (RS), Brazil using multiplex real-time polymerase chain reaction (mRT-PCR). The rabies virus was investigated by direct fluorescent antibody assay and intracerebral suckling mouse inoculation. The genomes of BoHV-1 and BoHV-5 were detected in 17% of samples. BoHV-5 and BoHV-1 were detected in 100% and 19% of BoHV positive samples, respectively, indicating the circulation of the pathogens in cattle herds in RS. The high Ct values and the absence of isolation suggest viral latency. Coinfection of herpesvirus and the rabies virus was detected in 28% of samples, although no significant association between pathogens was observed. Rabies was detected in 57.7% of suspected samples, confirming the importance of the disease in the state. Concerning the method by which samples were conserved, no significant difference was observed between the number of positive results in frozen and refrigerated samples.  相似文献   

5.
Respiratory diseases in calves are responsible for major economic losses in both beef and dairy production. Several viruses, such as bovine respiratory syncytial virus (BRSV), bovine herpes virus-1 (BoHV-1), bovine parainfluenza virus-3 (BPI-3V), bovine viral diarrhea virus (BVDV), and bovine adenoviruses (BAV), are detected in most clinical cases with respiratory signs. The aim of this study is to define seroprevalences of five major viral causes of bovine respiratory infections in cattle in central region of Iran (Esfahan province). The population targeted was 642 dairy cows (Holstein–Friesian) from 25 farms. Samples of blood serum from female cattle were examined. Sera were tested by commercial ELISA kits to detect antibody against BRSV, BoHV-1, BPI-3V, BVDV, and BAV-3. The results were analyzed by Chi-square test. In the present study, seroprevalences of BRSV, BoHV-1, PI3V, BVDV, and BAV-3 were 51.1%, 72%, 84.4%, 49.2%, and 55.6%, respectively. The present study shows that infections of bovine respiratory viruses are very common in cattle in Esfahan.  相似文献   

6.
This study demonstrated that bovine herpesvirus 5 (BoHV)-5 infected calves can develop encephalitis and remain asymptomatic. Seven calves were infected intranasally and monitored for 30 days. Cerebrospinal fluid (CSF) analysis was performed from the onset of neurological signs. Multiple sections of brain and the trigeminal ganglion were submitted to histopathology. Virus detection (PCR and isolation) was performed on CSF and tissues. Four calves developed signs of neurologic disease and died. Three calves remained asymptomatic and were euthanized 30 days post-infection. Cerebrospinal fluid mononuclear pleocytosis occurred in symptomatic and asymptomatic calves. BoHV-5 was isolated and viral DNA was detected in multiple areas of the encephalon of all calves. The viral DNA was detected in the CSF of 2 calves showing neurological signs. Histologically, inflammation was noted in the brain of all calves and confirmed that the encephalitis caused by BoHV-5 may be mild and asymptomatic.  相似文献   

7.
The biology of latent infection by bovine herpesvirus 2 (BoHV-2), the agent of mammillitis in cows, remains largely unknown. We herein report attempts to reactivate the latent infection and investigated the sites of BoHV-2 latency in experimentally infected sheep. Ewes inoculated with BoHV-2 in the udder’s skin shed virus for up to five days, developed mammillitis and seroconverted. However, attempts to reactivate latent infection by dexamethasone administration at day 40 pi failed. Nevertheless, viral DNA - and not infectious virus - was detected by PCR in several nerve ganglia and/or regional lymph nodes (LNs) of all animals at day 40 post-reactivation. Likewise, lambs previously inoculated with BoHV-2 in the nose harbored latent viral DNA in trigeminal ganglia, tonsils and regional LNs. These results demonstrate that BoHV-2 establishes latent infection in nerve ganglia and in regional lymphoid tissues, yet virus reactivation is not easily achieved by standard protocols used.  相似文献   

8.
Fetal serum from most of 994 bovine and 553 ovine aborted fetuses was tested serologically for antibodies to border disease (BD), bovine viral diarrhea (BVD), and bluetongue (BT) viruses, and to Leptospira sp., and the results were compared with the results of isolation procedures, fluorescent antibody tests (FAT), and histologic examinations of the same fetuses. Antibodies to BT virus were not found in any of the 994 bovine and 553 ovine fetuses. Antibody titers to BVD virus were present in 39 of 966 bovine fetuses tested, and BVD virus was detected in 4 of the 39. Four of 74 fetuses in which the BVD virus was detected by FAT or isolation had titers to BVD virus. Microagglutination (MAT) titers to 1 or more of 5 serovars of leptospires were present in 52 of 773 bovine fetal sera tested. Leptospires were not detected by FAT in any bovine fetuses that had leptospiral antibody titers. Leptospires were detected by FAT in 15 aborted calves, and none of these had MAT titers. Antibody titers to BD virus were present in 80 of 486 fetal lamb sera tested, and the virus was detected by FAT or isolation in 3 of the 80 fetuses. Border disease virus was detected in 14 of 486 fetal lambs tested. Twelve of the 14 were tested serologically and 3 had titers to BD virus. Leptospiral antibody titers were present in 27 of 326 ovine fetal sera tested. Leptospires were not detected in any of the 326 ovine fetuses tested by FAT.  相似文献   

9.
Seroepidemiological surveys were performed on neutralizing antibody to bovine herpesvirus 2 (BoHV-2) among cattle in Japan. A total of 1,819 sera were collected from cattle in 27 prefectures from 1997 to 1998. Antibodies were detected in only 18 sera collected from 4 prefectures. However, the most prevalent areas of the infection were found in two islands located in the subtropical zone. Additional 353 sera were collected in three including these islands in 1999-2001.The antibody-positive rates in the farms in these islands ranged from 10% to 81.1%. It was confirmed that BoHV-2 was prevalent in these areas. However, the infection seemed to be latent, because no diseases have been noticed. This is the first report showing the presence of BoHV-2 infection among cattle in Japan.  相似文献   

10.

Background

Bovine herpesvirus 5 (BoHV-5) is an alphaherpesvirus responsible for meningoencephalitis in young cattle and it is antigenically and genetically related to bovine herpesvirus 1. BoHV-5 outbreaks are sporadic and restricted in their geographical distribution, being mostly detected in the Southern hemisphere. The N569 and A663 strains are prototypes of the "a" and "b" subtypes of BoHV-5, however, scarce information about their in vitro and in vivo properties is currently available.

Methods

For the in vitro comparison between BoHV-5 A663 and N569 strains, viral growth kinetics, lysis and infection plaque size assays were performed. Additionally, an experimental infection of cattle with BoHV-5 A663 and N569 strains was carried out. Viral excretion, development of neurological signs, presence of specific antibodies in serum and nasal swabs and presence of latent BoHV-5 DNA in trigeminal ganglion, were analyzed. Histopathological examination of samples belonging to inoculated animals was also performed.

Results

The lytic capacity and the cell-to-cell spread was lower for the A663 strain compared to the N569 strain, however, the production of total infectious viral particles was similar between both strains. Concerning the in vivo properties, the A663 and N569 strains are able to induce similar degrees of pathogenicity in cattle.

Conclusions

Our results show that the A663 strain used in this study is less adapted to in vitro replication in MDBK cells than the N569 strain and, although slight differences were observed, both strains are able to induce a similar degree of virulence in the natural host.  相似文献   

11.
The ability of alphaherpesviruses to infect different ruminant species may have important implications for control/eradication efforts. Serological data indicate that goats may be naturally infected with bovine herpesviruses. To investigate the susceptibility of goats to bovine herpesvirus-5 (BoHV-5), 3-4-month-old kids were inoculated intranasally with each of three Brazilian BoHV-5 isolates (G1, n=8; G2, n=5; G3, n=5). The acute infection was characterized by virus shedding in nasal secretions for up to 14 days (titers up to 10(5.97)TCID(50)/mL), mild respiratory signs and conjunctivitis. All animals seroconverted to BoHV-5, developing virus neutralizing (VN) titers from 4 to 32 to the homologous viruses. At day 60 post inoculation (pi), two animals from each group were euthanized for tissue collection and the remaining goats were submitted to dexamethasone administration (0.4 mg kg(-1) for 5 days). Dexamethasone treatment resulted in virus reactivation in 9 out of 12 animals, as ascertained by virus shedding and/or by increase in VN titers. Virus shedding was detected in 8/12 animals and lasted from 1 to 9 days. Latent viral DNA was detected by PCR in the olfactory bulb and/or trigeminal ganglia of 6/6 goats euthanized at day 60 pi and in 12/12 animals euthanized 40 days post-dexamethasone. These results show that young goats are susceptible to BoHV-5 and may shed virus upon reactivation of latent infection. Thus, it is reasonable to expect that goats raised in close contact with cattle in areas where BoHV-5 is endemic may be infected and therefore should be considered potential reservoirs of the virus.  相似文献   

12.
Immunological parameters were studied among 23 late-term bovine fetuses. Epizootic bovine abortion (EBA) disease was induced in fetuses by feeding Ornithodoros coriaceus ticks on pregnant heifers. A spirochaete-like microorganism was detected in the blood of diseased fetuses and in inapparent natural infections in some abattoir-collected fetuses. Fetuses were classified according to stages of disease: EBA diseased (n = 10), EBA infected (n = 7) and normal (n = 6). Using flow cytometry, the presence of surface immunoglobulins (sIg) and peanut agglutinin (PNA) receptors were used to detect B and T lymphocytes, respectively. In peripheral blood of normal fetuses, most lymphocytes were identified as T or B cells, whereas about 20 per cent of lymphocytes in EBA diseased fetuses did not reveal the sIg or PNA receptor markers (null cells). Size and shape analyses by flow cytometry detected a population of enlarged lymphocytes in the EBA diseased fetuses. The numbers of cells bearing determinants reactive with monoclonal antibodies specific for bovine T cells (B26A and B29A) and B cells (TH21A) were considerably less than those expressing the PNA receptor and sIg. These results suggested that the monoclonal antibodies were binding to differentiation antigens which were not consistently expressed on the fetal cells. Radio-immunodiffusion was used to measure bovine IgM, IgG1 and IgG2 in fetal serum. The quantities of immunoglobulins were markedly increased in animals infected with the spirochaete-like organism (groups 1 and 2) and were assumed to result from fetal antibody synthesis.  相似文献   

13.
In this investigation the indirect fluorescent antibody technique was used to titrate antibodies in bovine sera to parainfluenza 3, infectious bovine rhinotracheitis virus and bovine viral diarrhea virus. These results were compared to those determined on the same samples by hemagglutination inhibition for parainfluenza 3 virus and serum neutralization for bovine virus diarrhea and infectious bovine rhinotracheitis virus. The results of the serological methods agreed closely. The indirect fluorescent antibody technique is a rapid and sensitive method for detecting antibodies and the procedure lends itself to use in diagnostic laboratories. In addition to the above viruses the presence or absence of antibodies to bovine coronavirus and bovine adenovirus 3 were determined by the indirect fluorescent antibody technique in thoracic fluids from 100 aborted fetuses and 50 nonaborted fetuses. Results on these samples were not compared to hemagglutination inhibition or serum neutralization as the condition of fluid samples from aborted fetuses renders interpretation of such tests unreliable. Antibodies to one or more viruses were detected in 30 of the 100 aborted fetuses and in seven of the 50 nonaborted fetuses. Antibodies to more than one agent were detected in eleven of the 100 aborted and in one of the 50 nonaborted fetuses. Reasons for this occurrence and application of the test in determination of causes of abortion are discussed.  相似文献   

14.
Bovine herpesvirus type 5 (BoHV-5) is the causative agent of bovine herpetic encephalitis. In countries where BoHV-5 is prevalent, attempts to vaccinate cattle to prevent clinical signs from BoHV-5-induced disease have relied essentially on vaccination with BoHV-1 vaccines. However, such practice has been shown not to confer full protection to BoHV-5 challenge. In the present study, an inactivated, oil adjuvanted vaccine prepared with a recombinant BoHV-5 from which the genes coding for glycoprotein I (gI), glycoprotein E (gE) and membrane protein US9 were deleted (BoHV-5 gI/gE/US9−), was evaluated in cattle in a vaccination/challenge experiment. The vaccine was prepared from a virus suspension containing a pre-inactivation antigenic mass equivalent to 107.69 TCID50/dose. Three mL of the inactivated vaccine were administered subcutaneously to eight calves serologically negative for BoHV-5 (vaccinated group). Four other calves were mock-vaccinated with an equivalent preparation without viral antigens (control group). Both groups were boostered 28 days later. Neither clinical signs of disease nor adverse effects were observed during or after vaccination. A specific serological response, revealed by the development of neutralizing antibodies, was detected in all vaccinated animals after the first dose of vaccine, whereas control animals remained seronegative. Calves were subsequently challenged on day 77 post-vaccination (pv) with 109.25 TCID50 of the wild-type BoHV-5 (parental strain EVI 88/95). After challenge, vaccinated cattle displayed mild signs of respiratory disease, whereas the control group developed respiratory disease and severe encephalitis, which led to culling of 2/4 calves. Searches for viral DNA in the central nervous system (CNS) of vaccinated calves indicated that wild-type BoHV-5 did not replicate, whereas in CNS tissues of calves on the control group, viral DNA was widely distributed. BoHV-5 shedding in nasal secretions was significantly lower in vaccinated calves than in the control group on days 2, 3, 4 and 6 post-challenge (pc). In addition, the duration of virus shedding was significantly shorter in the vaccinated (7 days) than in controls (12 days). Attempts to reactivate latent infection by administration of dexamethasone at 147 days pv led to recrudescence of mild signs of respiratory disease in both vaccinated and control groups. Infectious virus shedding in nasal secretions was detected at reactivation and was significantly lower in vaccinated cattle than in controls on days 11–13 post-reactivation (pr). It is concluded that the inactivated vaccine prepared with the BoHV-5 gI/gE/US9− recombinant was capable of conferring protection to encephalitis when vaccinated cattle were challenged with a large infectious dose of the parental wild type BoHV-5. However, it did not avoid the establishment of latency nor impeded dexamethasone-induced reactivation of the virus, despite a significant reduction in virus shedding after challenge and at reactivation on vaccinated calves.  相似文献   

15.
Bovine herpesvirus type 5 (BoHV-5) is an important pathogen that causes meningoencephalitis in cattle. Few studies have used the mouse as a model for BoHV-5 infection. Despite the fact that BoHV-5 can infect mice with immune deficiencies, little is known about viral replication, immune response, and the course of infection in the central nervous system (CNS) of wild-type mice. Therefore, the aim of this study was to evaluate the response in the CNS of BALB/c mice acutely infected with BoHV-5 at different days post-inoculation (dpi). BoHV-5, when inoculated intracranially, was able to infect and replicate within the CNS of BALB/c mice. Until 15 dpi, the mice were able to survive without showing prominent neurological signs. The infection was accompanied by a Th1 immune response, with a significant expression of the cytokines IFN-γ and TNF-α and chemokine CCL-2. The expression of these cytokines and chemokines was most significant in the early course of infection (3 and 4 dpi), and it was followed by meningoencephalitis with perivascular cuffing and periventriculitis, composed mainly of macrophages and lymphocytes. After the expression of cytokines and chemokine, the mice were able to curb BoHV-5 acute infection in the brain, since there was a decrease in the number of BoHV-5 DNA copies after 3 dpi and viable viral particles were not detected after 6 dpi. Importantly, BoHV-5 was able to infect the trigeminal ganglia during acute infection, since a large number of BoHV-5 DNA copies were detected on 1 and 2 dpi.  相似文献   

16.
An outbreak of contagious mastitis occurred among cattle on a farm, and bovine herpesviruses were isolated from the affected mammary tissues, scabs and abscess discharge of the cattle. A bovine herpesvirus type 4 (BoHV-4)-specific fragment was amplified from the isolates by polymerase chain reaction (PCR). Restriction endonuclease analyses demonstrated that the isolates were related to Movar-like European type BoHV-4. To determine the ratio of BoHV-4 subclinical infection in the cattle, a genomic survey was performed by PCR for cattle that were moved to the animal hygiene service station in Ibaraki prefecture. The BoHV-4 genome was occasionally detected in peripheral blood leukocytes, lymph nodes and nervous tissues. The rate of BoHV-4 subclinical infection was relatively high in the cattle.  相似文献   

17.
Three cattle were experimentally infected with bovine herpesvirus type 4 (BoHV-4), strain B11-41, isolated from the spinal cord of a cow, and monitored for clinical symptoms. None of them showed any clinical signs except increases of leukocyte numbers in two of them, and the body temperature remained normal throughout the experiment. Antibody titers against BoHV-4 continuously increased for one month and were maintained at a high level for more than 1 year by enzyme-linked immunosorbent assay (ELISA). The virus was isolated only from serum and peripheral blood leukocytes (PBL) of one cow in the early stage of infection, but the viral genome was detected in PBL continuously by PCR. When they were euthanized, the viral genome was detected in the lymph nodes and nervous tissues such as medulla, spinal cord, and trigeminal ganglion. These results indicate that cattle are infected with the virus latently and persistently, and the latency site would be in the tissues of the central nervous system as well as lymphoid tissues. When a seroepidemiological survey was performed on antibodies to BoHV-4 among cattle in Japan by ELISA, the rate of antibody-positive cattle was 8.9% and they were found irregularly on certain farms.  相似文献   

18.
The gamma-herpes virus bovine herpes virus type 4 (BoHV-4) is distributed worldwide in cattle populations with unknown pathogenicity. Bovine endothelial cells were recently shown to be susceptible to BoHV-4 infection in vitro and this virus accelerated the cholesterol-induced atherosclerotic process in rabbits. In this study, the in vivo effect of BoHV-4 on cardiovascular tissue was investigated by intravenous infection of rabbits fed a cholesterol free diet. Inflammatory lesions of vascular tissue in aortic and valvular endothelial cells, and smooth muscle cells were detected by H&E staining, PCR, IF, EM immunohistochemistry, while virus isolation was used to detect virus particles. Acute and chronic vasculitis, signs of chronic endocarditis, with mononuclear cell accumulation and a fresh thrombus was found. Herpes viruses have already been thought to initiate cardio-vascular disorders, now this paper shows that a bovine gamma-herpes virus could also be a causative agent of vascular lesions in mammals fed a normal diet. BoHV-4-infection of rabbits could serve as a useful animal model for research into virus-induced human cardio-vascular diseases.  相似文献   

19.
In this study, the expression levels of viral Toll-like receptors (TLRs) in the nervous system of bovine herpesvirus type 5 (BoHV-5)-infected calves were investigated. A significant increase in the expression of TLRs 3 and 7–9 was found in the anterior cerebral cortex during acute infection and viral reactivation. In the trigeminal ganglia, only TLR9 expression was significantly affected. The magnitude of the increase was lower in BoHV-1-infected calves, suggesting that a restricted immune response might protect against exacerbated inflammatory responses in the brain. This work describes, for the first time, the involvement of TLRs 3 and 7–9 in the recognition of BoHV in the bovine nervous system, indicating that the expression of these receptors might be associated with the development of neurological disease. Modulation of the signalling pathways mediated by TLRs might provide an effective approach to control the neuro-immune response to BoHV-5, which may be responsible for neurological lesions.  相似文献   

20.
Neurotrophic factors have been implicated in the control of neuronal survival and plasticity in different brain diseases. Meningoencephalitis caused by bovine alpha-herpesvirus 5 (BoHV-5) infection is a frequent neurological disease of young cattle, being the involvement of apoptosis in the development of neuropathological changes frequently discussed in the literature. It’s well known that Toll-like receptors (TLRs) can activate neuroinflammatory response and consequently lead to neuronal loss. However, there are no studies evaluating the expression of neurotrophic factors and their association with brain pathology and TLRs during the infection by BoHV-5. The current study aimed to analyze brain levels of neurotrophic factors along with neuropathological changes during acute infection by BoHV-5 in wild-type (WT) and TLR3/7/9 (TLR3/7/9−/−) deficiency mice. The infection was induced by intracranial inoculation of 1 × 104 TCID50 of BoHV-5. Infected animals presented similar degrees of clinical signs and neuropathological changes. Both infected groups had meningoencephalitis and neuronal damage in CA regions from hippocampus. BoHV-5 infection promoted the proliferation of Iba-1 positive cells throughout the neuropil, mainly located in the frontal cortex. Moreover, significant lower levels of brain-derived neurotrophic factor (BDNF) were detected in both BoHV-5 infected WT and TLR3/7/9 deficient mice, compared with non-infected animals. Our study showed that BDNF down regulation was associated with brain inflammation, reactive microgliosis and neuronal loss after bovine alpha-herpesvirus 5 infection in mice. Moreover, we demonstrated that combined TLR3/7/9 deficiency does not alter those parameters.  相似文献   

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