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1.
This article summarizes the results of a study on several strains of Bovid herpesvirus-4 (BHV-4), isolated from cattle. The study had several objectives, namely, to verify (a) the disease-causing potential of the virus, (b) the possibility by BHV-4 to induce a latent infection in the natural host and (c) the entity of the relationships among strains of the virus isolated from different disease syndromes. The following data were obtained: (1) All strains tested were able to replicate in experimentally infected calves; however, only one strain (85/BH 16TV) caused an overt systemic disease. (2) The nervous system as well as the lymphoid structures appeared to be the target organs for replication of the virus. (3) BHV-4, like other herpesviruses, was able to establish latent infection in cattle. (4) When two strains of the virus, isolated from cattle affected by different disease syndromes, i.e. respiratory disease (strain DN-599) or vulvovaginitis (strain 85/BH 16TV), respectively, they resulted to be closely related to each other. In particular, they revealed a similar DNA pattern and both strains were able to cause respiratory disease in calves. Moreover, the two viral strains were mutually protective in that calves were generally found to be refractory to challenge inoculation with either the homologous or the heterologous virus. (5) All BHV-4 strains tested generally failed to evoke a significant production of neutralizing antibody in the experimental calves.  相似文献   

2.
Recrudescence of bovine herpesvirus-5 in experimentally infected calves   总被引：2，自引：0，他引：2  
A latent infection of bovine herpesvirus-5 (BHV-5) was established in 4 calves. These calves, plus 2 controls, were given dexamethasone (DM) to reactivate the latent virus. The 4 principal calves developed antibodies to BHV-5 by postinoculation day (PID) 21. Antibody titers increased until PID 42 before decreasing to low levels of PID 75. After the first DM treatment (started on PID 76), an anamnestic antibody response was demonstrated in the 4 principal calves. Calves, 2, 3, and 4 were euthanatized and necropsied at PID 121, and their antibody titers were again decreasing. The virus BHV-5 was not isolated from the tissues by conventional techniques of viral isolation but was isolated from the trigeminal ganglion and spinal cord of calf 3 by explantation techniques. The BHV-5 was isolated, using conventional viral isolation techniques, from a nasal swab sample of calf 1 on PID 91 (15 days after the first DM treatment) and from the thoracic lymph node 6 days after the start of a 2nd DM treatment. Seemingly, BHV-5 may be latently harbored in the nerve tissues or calves and this virus may be reactivated from the upper respiratory tract following subsequent DM treatment.  相似文献   

3.
Two strains of Bovid herepesvirus-4 (BHV-4), i.e. the prototype strain DN-599, obtained from a steer suffering of a respiratory disease, and the strain 85/BH 16TV, originated from a cow with vulvovaginitis, were compared in studies which included restriction endonuclease analysis, experimental infection and reciprocal cross protection tests. The restriction endonuclease analysis revealed that the resultant DNA patterns of the isolates were generally similar with only a difference in one fragment. The two strains were capable of causing respiratory tract infection in calves, even if they displayed a different level of virulence: the strain 85/BH 16TV being the most virulent while the strain DN-599 the least. The two viral strains were mutually protective in that the calves were generally found to be refractory to challenge inoculation with either the homologous or the heterologous virus. Finally, both viral strains failed to evoke the production of neutralizing antibody in the experimental calves.  相似文献   

4.
A study was carried out to determine whether bovid herpesvirus-2 (BHV-2) is able to induce a recurrent infection in experimentally infected calves. Twelve calves infected with the virus were treated with dexamethasone (DMS) beginning 69 days after the infection, ie, several weeks after the animals had recovered from the disease and were negative for BHV-2. The stress induced by DMS treatment failed to reactivate the clinical condition or to induce shedding of BHV-2. However, treatment with DMS reactivated a latent infectious bovine rhinotracheitis (IBR) virus infection in all calves previously inoculated with BHV-2, and also in 2 noninoculated controls. The reactivation of IBR virus occurred without any clinical evidence of the disease, but the virus was isolated from nasal and pharyngeal swabbings and from the organs. A proliferative ganglionitis of the trigeminal ganglion was also observed. Because of the interference by IBR virus, this study did not resolve the question as to whether BHV-2 can induce a recurrent infection.  相似文献   

5.
The strain BA-1 of caprine herpesvirus-1 (CpHV-1), isolated from latently infected goats, was inoculated intranasally into three five-year-old goats. The animals developed fever and leukopenia. The signs began on post-inoculation day (PID) 4 and lasted 7 days. In one goat herpes-like lesions appeared on the vulvar area on PID 7. Virus was consistently recovered from the nasal and the vaginal swabbings obtained from the three goats. Virus was never recovered from the ocular and rectal swabbings nor from any buffy coat samples. However, the buffy coats were positive for viral DNA detected by polymerase chain reaction (PCR). All isolates from the experimental goats were identical in their restriction patterns to the original BA-1 and were similar to the reference E/CH strains of CpHV-1.  相似文献   

6.
Four bovine herpesvirus-1 (BHV-1) commercial vaccines, three of which (vaccines B, D, E) were modified live vaccines (MLV) and one (vaccine A) identified as a live strain of BHV-1 gE negative, were used for vaccination of calves, using three calves for each vaccine. Three months after vaccination calves were subjected to dexamethasone (DMS) treatment following which virus was recovered from calves inoculated with vaccine B and from those given vaccine D. No virus reactivation was obtained in calves, which received vaccines A or E. The DNA extracted from the two reactivated viruses was subjected to restriction endonuclease analysis. The restriction pattern of the isolate obtained from calves vaccinated with vaccine D differs significantly from that of the original vaccine, whereas the reactivated virus from calves given vaccine B conserved the general pattern of the original vaccine strain. For each reactivated virus in this experiment (B and D) as well as for the isolate obtained from calves vaccinated with a further MLV (vaccine C) in a previous trial, three calves were inoculated. No clinical signs of disease were detected in any of the inoculated calves during the observation period. When the nine calves were exposed 40 days later to challenge infection with virulent BHV-1, they remained healthy and no virus was isolated from their nasal swabbings. These results indicate that some BHV-1 vaccines considered in the project can establish latency in the vaccinated calves, however, the latency does not appear to interfere with the original properties of the vaccines in terms of safety and efficacy.  相似文献   

7.
A bovine herpesvirus-1 (BHV-1) isolate (FI) from an aborted fetus was used to infect 9 heifers at various stages of gestation. Two heifers were inoculated IV on postbreeding day (PBD) 1, 7, or 14, and 3 heifers were inoculated in the sixth month of pregnancy. Plasma progesterone assays were used to monitor corpus luteum function in heifers inoculated during early pregnancy. Low progesterone values and infertility were seen in the 2 heifers inoculated on PBD 1. Luteal function remained normal in heifers inoculated on PBD 7 or 14. These 4 heifers inoculated on PBD 7 or 14 carried their fetuses to term, and their calves were free of BHV-1 infection at birth. Three heifers inoculated during the sixth month of pregnancy also carried their fetuses to term. Two calves were born alive, and BHV-1 was not isolated from nasal swab samples of either calf; the third calf was stillborn. Virus was not isolated from the stillborn calf's tissues, but BHV-1 was isolated from the placenta. Lesions were not detected in several tissues examined by light microscopy, and BHV-1 antigen was not detected by immunohistochemical examination of paraffin sections. Restriction endonuclease analysis of viral DNA was used to compare the FI virus to other BHV-1 isolates (Colorado-1, Iowa, and K22). On the basis of restriction endonuclease analysis, the FI isolate should be classified as a type-2 (infectious pustular vulvovaginitis) virus, specifically subtype a.  相似文献   

8.
12 Large-White-Landrace piglets were subdivided in four groups of 3 and housed in separate units. The piglets of three groups were inoculated with the 86/27V 6C2 thymidine kinase negative (TK-) mutant of pseudorabies virus (PRV), by different routes. A second inoculation with the same mutant was given to the pigs 21 days later. The animals of a fourth group were left as uninoculated controls. 21 days following the second inoculation with the TK- mutant all pigs were challenge infected with the virulent PRV. On post challenge day (PCD) 30 all pigs were killed and samples for virus detection and histology were taken from several organs. The inoculated TK- mutant of PRV did not induce any ill effects in the pigs except a transient febrile reaction in some animals. Virus was recovered from nasal swabbings from one pig 2 days after the first inoculation of the mutant. After challenge exposure with virulent PRV, the TK- mutant-inoculated pigs were apparently protected, whereas the control pigs all were severely affected and recovered very slowly over 3 weeks. Virus was isolated from the nasal swabbings from the TK- mutant-inoculated pigs on PCDs 2 and 4, whereas the nasal swabbings from the control piglets were all positive for virus from PCD 2 through PCD 10. DNA analysis of the virus recovered showed a pattern identical to that of the virulent PRV. Histologic lesions were found in the respiratory and the central nervous systems, however, the lesions in the TK- mutant-inoculated pigs were much milder compared to those registered for the control pigs. Virus was not isolated from any of the tissue samples that were tested, but viral DNA with sequences typical of PRV genome was detected by PCR in all samples of trigeminal ganglia from either the TK- mutant-inoculated pigs or from the controls.  相似文献   

9.
Four calves latently infected with infectious bovine rhinotracheitis virus (IBRV) were used to compare the ease of isolation of virus from neuronal ganglia and from mucosal surfaces. Two calves were slaughtered, and neuronal ganglia (cranial cervical, trigeminal, and 3rd and 4th sacral) were cocultivated on bovine fetal kidney cells. Virus was not isolated. Two calves given dexamethasone for 4 days were slaughtered on the 5th day. Virus was not isolated from cocultivated or macerated neuronal ganglia, but virus was isolated from nasal secretions taken from both calves on the day of slaughter. Eleven calves were inoculated with IBRV via different routes and were treated with dexamethasone 3 to 4 months after inoculation. virus was isolated from the nasal cavities, but not the vaginas of 6 heifers inoculated intranasally, and was isolated from the vaginas, but not the nasal cavities of 2 heifers inoculated intravaginally. Of 3 calves inoculated IV, virus was isolated from the nasal cavities of 3, from the oropharynxes of 2, and from the prepuce of 1.  相似文献   

10.
Twelve 1-week-old colostrum-deprived lambs inoculated with the RTS-42 strain of Mastadenovirus ovi 5 were killed and necropsied (2 lambs/day) on postinoculation days (PID) 2, 4, 6, 8, 12, and 21. Four noninoculated lambs were killed and necropsied (2/day) on PID 6 and 12. Virus was isolated from nasal secretions and feces on PID 1 to PID 6, from tracheal fluids and lung tissue of lambs necropsied on PID 2, 4, and 6, and from lung tissue from 1 lamb necropsied on PID 8. Virus was not recovered from liver, kidney, or small intestine of inoculated lambs or samples from noninoculated lambs. Serum antibody was first detected on PID 6 in the inoculated lambs. Noninoculated lambs remained seronegative. None of the lambs in the study developed clinical signs of infection although lesions were produced in the respiratory tract.  相似文献   

11.
Sixteen 20 day old pigs, devoid of neutralizing antibody to pseudorabies virus (PRV), were divided into two groups of eight, and the animals of each group were housed in a separate unit. In each group 6 pigs were inoculated intranasally with the thymidine kinase (TK−) mutant (Group 1) or the field strain of PRV (Group 2), each pig receiving an inoculum of 4 ml. The remaining 2 pigs in each group served as uninoculated controls. The only clinical sign observed in the pigs of Group 1 was a transient febrile reaction, in the case of six pigs inoculated with the TK− mutant of PRV, whereas no signs of disease were seen in the uninoculated controls. The virus was isolated from the 6 infected pigs of the group only on post infection day (PID) 2, whereas it was never isolated from the controls. By contrast, the pigs of Group 2, had a severe clinical response and one, among those that were inoculated with the field strain of the PRV, died on PID 9. Virus was consistently isolated from all pigs of Group 2, inoculated and control. On PID 30 all pigs, i.e. the 8 of Group 1 and 7 of the Group 2 which survived to the infection, were subjected to dexamethasone (DMS) treatment. After DMS treatment virus was never isolated from the nasal swabbings obtained from the pigs of Group 1, whereas it was consistently isolated from pigs of Group 2. After 30 d from the start of DMS treatment the pigs were killed and several tissues were collected from each pig for virus detection, by isolation in tissue culture and by PCR analysis. At necropsy no lesions were found in pigs of Group 1, whereas acute pneumonia and gliosis in the trigeminal ganglia were observed in pigs of Group 2. Virus was never isolated from any of the tissues taken from pigs of both, Group 1 and Group 2, nevertheless sequences of PRV were detected by PCR analysis in the trigeminal ganglia of the pigs of both Groups.  相似文献   

12.
Calves infected with bovine herpesvirus-1 (BHV-1) or both BHV-1 and parainfluenza-3 virus (PIV-3) developed clinical signs including fever, cough, and nasal and ocular discharges. Animals infected with both viruses appeared more depressed and showed higher rectal temperature, while calves inoculated with PIV-3 alone had a very mild clinical disease. Both BHV-1 and PIV-3 were recovered from nasal secretions up to six to eight days postinoculation. However, the virus titers were lower in calves with mixed infection. An increase in serum antibodies to both BHV-1 and PIV-3 was detected by serum neutralization and enzyme-linked immunosorbent assay. Antibody responses were delayed and significantly lower in calves given mixed infection than in calves infected with a single virus. Interleukin-2 activity in cultures of lymphocytes from BHV-1 and BHV-1 plus PIV-3 infected calves was higher compared to control calves.  相似文献   

13.
OBJECTIVE: To determine whether a combination viral vaccine containing modified-live bovine herpesvirus-1 (BHV-1) would protect calves from infection with a recent field isolate of BHV-1. DESIGN: Randomized controlled trial. ANIMALS: Sixty 4- to 6-month-old beef calves. PROCEDURE: Calves were inoculated with a placebo 42 and 20 days prior to challenge (group 1; n = 10) or with the combination vaccine 42 and 20 days prior to challenge (group 2; 10), 146 and 126 days prior to challenge (group 3; 10), 117 and 96 days prior to challenge (group 4; 10), 86 and 65 days prior to challenge (group 5; 10), or 126 days prior to challenge (group 6; 10). All calves were challenged with BHV-1 via aerosol. Clinical signs, immune responses, and nasal shedding of virus were monitored for 14 days after challenge. RESULTS: Vaccination elicited increases in BHV-1-specific IgG antibody titers. Challenge with BHV-1 resulted in mild respiratory tract disease in all groups, but vaccinated calves had less severe signs of clinical disease. Extent and duration of nasal BHV-1 shedding following challenge was significantly lower in vaccinated calves than in control calves. In calves that received 2 doses of the vaccine, the degree of protection varied with the interval between the last vaccination and challenge, as evidenced by increases in risk of clinical signs and extent and duration of viral shedding. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that this combination vaccine provided protection from infection with virulent BHV-1 and significantly reduced nasal shedding of the virus for at least 126 days after vaccination.  相似文献   

14.
Interferon, fluorescent antibody, and neutralizing antibody responses were studied in sera of 9 calves inoculated with bovine respiratory syncytial virus, in relation to viral shedding and clinical signs of disease. The calves (5.5 to 6.5 weeks of age) were assigned to 3 groups. Group I was inoculated once with the virus, and groups II and III were challenge exposed at postinoculation day (PID) 15 or 37. Serum-neutralizing and indirect fluorescent antibody techniques were used to measure antibody responses. The plaque-inhibition technique, using vesicular stomatitis virus, was applied to measure serum interferon titers. The virus was recovered by inoculation of nasal secretions onto cell cultures. Fluorescent antibody was detected in all calves on PID 3, with maximum titers appearing approximately on PID 10. Low neutralizing antibody was detected in most animals on PID 3, and titers peaked approximately 4.5 weeks after inoculation and then decreased. Interferon titers were high in all calves during the early stage of infection, dropped to undetectable amounts by PID 6, and reappeared in low amounts at least 1 week later. All infected calves manifested clinical signs of disease by PID 4 to 9. Clinical signs of disease were not observed after challenge exposure at PID 15 or 37, and anamnestic responses were not detected. Virus was recovered after challenge exposure at PID 15, but not at PID 37.  相似文献   

15.
Eleven 3- to 50-day-old colostrum-deprived gnotobiotic calves and seven 25- to 63-day-old colostrum-deprived conventional calves were allotted into 3 groups. Each group was inoculated with a fecal isolate of bovine coronavirus via different routes: orally/intranasally OR/IN, No. 1 through 8, group 1 calves; OR, No. 9 through 13, group 2 calves; IN, No. 14 through 18, group 3 calves. Nasal swab specimens and fecal specimens were collected daily and were examined for coronavirus antigen by use of direct immunofluorescent staining (nasal epithelial cells) or by use of immune electron microscopy (fecal specimens). All but 4 calves (No. 11, 13, 17, and 18) were euthanatized on postinoculation days (PID) 3 to 7. Calves 11 and 17 became severely dehydrated and died at PID 5. Calves 13 and 18 were evaluated for nasal and fecal shedding of coronavirus through PID 14. Distribution of coronavirus antigen in the respiratory and intestinal tracts of the 14 euthanatized calves was evaluated by use of direct immunofluorescent staining. All calves developed profuse diarrhea by PID 2 to 4; however, calves did not develop clinical signs of respiratory tract disease before euthanasia or death. Inoculated calves shed coronavirus in their feces as detected by use of immune electron microscopy. Infected nasal epithelial cells were detected in all but 2 orally inoculated calves (No. 9 and 10). Route of inoculation influenced the sequence of initial detection of coronavirus antigen from fecal specimens or nasal swab specimens.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

16.
Twelve 1-week-old colostrum-deprived lambs that were inoculated with ovine adenovirus isolate RTS-151 developed a mild febrile response between postinoculation days (PID) 4 and 10. They were inactive and some had serous nasal discharges; their respiratory rates and efforts were increased. Virus was isolated from nasal secretions from PID 2 to PID 8. Virus also was isolated from tracheal fluid and lung tissue of most lambs at necropsy (between PID 2 and 12), but not from liver, kidney, small intestine, and feces, indicating that the infection was confined to the respiratory tract. Four control lambs remained healthy and neither virus nor serum antibody was detected.  相似文献   

17.
OBJECTIVE: To determine the efficacy of a modified-live virus vaccine containing bovine herpes virus 1 (BHV-1), bovine respiratory syncytial virus (BRSV), parainfluenza virus 3, and bovine viral diarrhea virus (BVDV) types 1 and 2 to induce neutralizing antibodies and cell-mediated immunity in na?ve cattle and protect against BHV-1 challenge. ANIMALS: 17 calves. PROCEDURES: 8 calves were mock-vaccinated with saline (0.9% NaCl) solution (control calves), and 9 calves were vaccinated at 15 to 16 weeks of age. All calves were challenged with BHV-1 25 weeks after vaccination. Neutralizing antibodies and T-cell responsiveness were tested on the day of vaccination and periodically after vaccination and BHV-1 challenge. Specific T-cell responses were evaluated by comparing CD25 upregulation and intracellular interferon-gamma expression by 5-color flow cytometry. Titration of BHV-1 in nasal secretions was performed daily after challenge. Results-Vaccinated calves seroconverted by week 4 after vaccination. Antigen-specific cell-mediated immune responses, by CD25 expression index, were significantly higher in vaccinated calves than control calves. Compared with control calves, antigen-specific interferon-gamma expression was significantly higher in calves during weeks 4 to 8 after vaccination, declining by week 24. After BHV-1 challenge, both neutralizing antibodies and T-cell responses of vaccinated calves had anamnestic responses to BHV-1. Vaccinated calves shed virus in nasal secretions at significantly lower titers for a shorter period and had significantly lower rectal temperatures than control calves. CONCLUSION AND CLINICAL RELEVANCE: A single dose of vaccine effectively induced humoral and cellular immune responses against BHV-1, BRSV, and BVDV types 1 and 2 and protected calves after BHV-1 challenge for 6 months after vaccination.  相似文献   

18.
Thirteen crossbred heifers seronegative for bovine herpesvirus-1 (BHV-1) were bred naturally to a seronegative bull. Eight heifers were inoculated with BHV-1, IV, on postbreeding day (PBD) 7 or 14. Viremia was detected in heifers 1 through 7, and virus also was isolated from nasal and vaginal secretions of heifers 2, 3, 4, 6, and 7. The pregnancy status of all heifers was monitored from PBD 14 to PBD 35 by determining plasma progesterone concentrations at 1- to 3-day intervals. Decreased progesterone values indicated that pregnancy was not maintained in BHV-1-inoculated heifers 2, 3, 4, 6, 7, and 8. The postbreeding interestrual period of these 6 heifers was normal or only slightly longer than would be expected in the absence of conception. All 5 noninoculated heifers were pregnant on PBD 35. Three to 4 months after acute infection, all BHV-1 inoculated heifers were treated with dexamethasone for 5 days and were euthanatized. Nasal and vaginal swab specimens were tested daily during dexamethasone treatment for excreted BHV-1, and reproductive tissues and adrenal glands were collected at necropsy for virologic tests and histopathologic examination. Virus reactivation was demonstrated in heifers 2 through 8. The BHV-1 isolations were made from adrenal glands of heifers 2, 3, 5, 6, 7, and 8, vaginal swab specimens of heifers 2, 3, 4, 6, and 7, and nasal swab specimens of heifers 2, 3, and 6. Only heifer 3 had virus in reproductive tissues; these isolations were made from ovary, infundibulum, and uterine tube, but not from endometrium.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

19.
The immunologic response of colostrum-deprived calves to parainfluenza-3 (PI-3) virus given by intranasal inoculation was studied. Inoculation of calves with 3.2 x 10(6) median cell culture infective doses (CCID50) of either virulent (SF-4) virus or a modified strain of PI-3 virus, or with 2.0 x 10(8) CCID50 of SF-4 virus, stimulated development of both serum antibody and nasal secretion (NS) antibody. However, NA antibody decreased in all calves between the 16th and 42nd postinoculation days and was present only at low or moderately low concentrations on the 126th day, when the immunity of the calves was challenged. Generally, calves that were inoculated with 3.2 x 10(6) CCID50 of SF-4 virus developed slightly higher concentrations of serum and NS antibodies than did calves inoculated with modified virus. Calves that were inoculated with 2.0 x 10(8) or 3.2 x 10(6) CCID 50 of SF-4 virus developed comparable concentrations of serum antibody, but large doses of SF-4 virus were less effective than smaller doses of the same virus in stimulating the development of NS antibody. Reinoculation of 3 calves with modified PI-3 virus resulted in a demonstrable increase in serum antibody in 2 calves and an increase and subsequent decrease in NS antibody in all calves. Challenge exposure of inoculated calves to aerosols of SF-4 virus failed to cause clinical signs of disease, and the challenge virus was not isolated from the nasal passages.  相似文献   

20.
Four Merino lambs were intranasally inoculated with bovine herpesvirus type 5 (BHV-5) reference strain N569. Two lambs were mock-inoculated as negative controls. The virus-inoculated animals developed apathy, inappetence, rhinitis, nasal, ocular and genital discharge, slight diarrhea and neurological disorders, like tremor and salivation. BHV-5 was isolated from the nasal discharge in two of the animals, while the polymerase chain reaction (PCR) detected the virus in all the infected lambs. Two lambs died on post infection day (PID) 13, while the other two infected animals were euthanized on PID 15 and 30. Gross pathological changes were not observed, however, histopathological examinations revealed diffuse nonsuppurative meningo-encephalitis in all infected animals. Viral antigen was detected by immunohistochemistry and viral nucleic acid was revealed by in situ hybridization in the brain of the two lambs, which died on PID 13. The virus was demonstrated by virus isolation and by PCR from different organs of all the infected animals. Slight rise of antibodies was observed in the infected animals from PID 15. The results show that BHV-5 is able to cross the species barrier and may establish infection in sheep.  相似文献   

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