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1.
Specific-pathogen-free embryos (18-day incubation) and hatched chicks were inoculated with a recombinant avian leukosis virus (ALV) produced by recombinant DNA techniques. Enzyme-linked immunosorbent assays were used to measure the production of viral-protein-specific antibody and the viral protein, p27, in the serum at 2, 5, 8, 14, and 20 weeks of age. Of the inoculated chickens surviving to 20 weeks, 64% produced viral-protein-specific antibodies and 42% transiently produced the viral protein, p27. Chickens inoculated as embryos did not differ significantly from those inoculated at hatch with respect to antibody and viral protein production. Antibody production peaked at 5 weeks postinoculation and declined over the remaining 15 weeks of the study. No evidence of chronic tolerant infection or mortality due to neoplastic disease was found.  相似文献   

2.
In studies with chicks inoculated with the Sk-1 strain of infectious bursal agent the bursa of Fabricius was found to be the tissue of choice for virus isolation as well as for use in the fluorescent antibody test and the agar gel diffusion test. In separate experiments positive results were obtained until postinoculation days 3 or 4 by the agar gel diffusion test, 5 or 6 by the fluorescent antibody test and 14 by the virus isolation method, respectively. Bursas from chickens involved in seven natural outbreaks of infectious bursal disease were then examined by these three methods. Virus was isolated from six outbreaks and infectious bursal agent antigen was demonstrated in three by the agar gel diffusion test method and seven (three by direct examination and four after one passage in chicks) by the fluorescent antibody test method. Passage in chicks was required when nonspecific fluorescence complicated the interpretation of fluorescent antibody test results.  相似文献   

3.
Quail (Coturnix coturnix japonica) and broiler (Gallus domesticus) chicks were inoculated experimentally with IBH virus (avian adenovirus-1) derived from quails to determine its pathogenicity. Quail chicks were inoculated by the intraperitoneal route at 3, 4, 5, 6 or 7 weeks of age. Lesions were encountered most frequently in the liver, kidneys and lungs. These included pale, swollen and mottled liver, swollen nephrotic kidneys, and congested and pneumonic lungs. The lesions were severe in birds inoculated at 5 weeks of age. Large basophilic intranuclear inclusion bodies were seen in hepatocytes and occasionally in the renal epithelium. The results showed that this isolate is pathogenic for quails above 3 weeks of age. Broiler chicks were inoculated at 4 weeks of age by the intraperitoneal route. The lesions produced in these chicks were similar to those of adenovirus-induced inclusion body hepatitis. Viral antigen was also demonstrated by dot-ELISA in suspensions of liver tissue from both quail and broiler chicks.Abbreviations AAF amnio-allantoic fluid - AAV avian adenovirus - DPI days post inoculation - EID50 dose infective for 50% of embryos - ELISA enzyme-linked immunosorbent assay - IBH inclusion body hepatitis - INIBs intranuclear inclusion bodies - NAF normal allantoic fluid  相似文献   

4.
J M Sharma 《Avian diseases》1985,29(4):1155-1169
Studies with specific-pathogen-free chickens revealed that chicks hatching from eggs inoculated at the 18th day of embryonation with infectious bursal disease (IBD) vaccine viruses of low virulence (isolates TC-IBDV and BVM-IBDV) developed antibody against IBD virus (IBDV) and resisted challenge with virulent IBDV at 3 weeks of age or older. Embryo vaccination did not adversely affect hatchability of chicks or survival of hatched chicks. Chicks embryonally vaccinated with TC-IBDV had transient histologic lesions in the bursa of Fabricius at hatch. Similar but milder lesions were also noted in chickens that received TC-IBDV at hatch. The level of protection following embryo vaccination with TC-IBDV and BVM-IBDV was similar to that following vaccination with the same vaccines at hatch. Vaccine viruses of moderate virulence (isolates BV-IBDV and 2512-IBDV) were not suitable as vaccines in embryos lacking maternal antibody to IBDV, because the vaccinated chicks developed acute IBD after hatch. Isolate 2512-IBDV was not pathogenic for embryos bearing maternal antibody to IBDV. Maternal antibody against IBDV interfered with efficacy of embryo vaccination with BVM-IBDV but not with 2512-IBDV. Embryo vaccination with a mixture of vaccines against IBD and Marek's disease resulted in protection of hatched chicks against challenge with virulent IBDV and Marek's disease virus.  相似文献   

5.
Detection of avian encephalomyelitis virus   总被引：2，自引：0，他引：2  
Methods for the detection of two strains of avian encephalomyelitis virus (AEV) in chick embryo brain cell cultures and chickens were compared. It was found that the agar gel precipitin test (AGPT) and the enzyme-linked immunosorbent assay (ELISA) carried out on the serum of inoculated chickens were more sensitive than either the indirect fluorescent antibody test in cell cultures or the detection of clinical signs in chicks. On the basis of results obtained in this experiment the effects were then determined of routes and time of inoculation of chickens on the detection of AEV. It was found that birds infected at two weeks old produced higher antibody titres than one-day-old birds and the AGPT and ELISA detected comparable levels of antibody in them. It was recommended that the tests to detect the presence of AEV as a contaminant of vaccines be replaced by a serological test carried out on chicks inoculated intramuscularly at two weeks old.  相似文献   

6.
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7.
Commercially bred chicks with maternally derived antibody to avian infectious bronchitis virus (IBV) were hatched in isolated conditions and a number vaccinated within the first three weeks of life with live IBV strain H120. Humoral antibody responses were assayed by haemagglutination inhibition (HI) or neutralisation (SN) tests, and the degree of protection against challenge with the virulent Massachusetts M41 strain assessed on the basis of tracheal ciliary activity four days after challenge. Maternal antibody in unvaccinated chicks declined linearly with a mean half-life of five to six days based on both HI and SN tests; these chicks were protected against challenge until four weeks old. There was complete correlation between ciliary activity and histopathological findings, but little between protection and antibody titre. It was concluded that the optimum age for primary vaccination was about two weeks.  相似文献   

8.
J M Sharma 《Avian diseases》1987,31(3):570-576
Several oncogenic and non-oncogenic isolates of Marek's disease virus (MDV) were inoculated into embryonated eggs on embryonation day (ED) 16 to 18, and embryos or chicks hatching from inoculated eggs were examined for infectious virus and viral internal antigen (VIA) in lymphoid organs. There was no evidence of extensive replication of MDV in any of the embryonic tissues examined. Levels of VIA peaked 4-5 days after chicks hatched. This indicated that MDV remained inactive during embryonation and did not initiate pathogenic events until chicks hatched. Because HVT replicated rapidly in the embryo but MDV did not, in ovo inoculation of HVT simultaneously with oncogenic MDV or several days after MDV resulted in significant protection (P less than 0.025) of hatched chicks against Marek's disease (MD). Little protection was obtained if HVT was given simultaneously with MDV or after MDV to chicks already hatched. The relative susceptibility of the embryo to extensive replication of the vaccine virus but not the challenge virus apparently accounted for protection against MD in chicks hatching from dually infected eggs.  相似文献   

9.
An attenuated recombinant avian leukosis virus (ALV) produced by recombinant DNA techniques was examined for its ability to provide resistance to Rous sarcoma virus (RSV) challenge. Specific-pathogen-free chicken embryos (18-day incubation) and hatched chicks inoculated with recombinant ALV produced significantly smaller tumors than sham-inoculated controls upon challenge with RSV 2 weeks postinoculation; inoculation with RAV-1 produced similar results. Specific-pathogen-free hens inoculated with recombinant ALV produced viral-protein-specific antibody that was transmitted to 100% of the progeny, as detected by enzyme-linked immunosorbent assay. Progeny of the inoculated hens produced significantly fewer tumors than sham-inoculated controls upon challenge with RSV at hatch, indicating that maternal antibody may be a factor in resistance to tumor development.  相似文献   

10.
Posthatched naive or inoculated male broiler chicks were kept in separate rooms. An inoculum was prepared from intestines of stunting-syndrome affected broiler chicks. Tap water was supplied from 2 L cups, 1 cup per pen. In the Ist experiment, the naive chicks were provided with tap water only and the inoculated ones had free access to tap water or to an electrolyte solution. In the 2nd experiment, the naive and inoculated birds had free access to water in addition to an electrolyte solution. Supplementation was provided up to 3 weeks of age; thereafter all chicks had access to tap water only. Water or electrolyte consumption and body weight (BW) were determined. Total water intake of inoculated chicks was higher than that of naive counterparts (P<0.001). Electrolyte supplementation increased drinking (P<0.001) in inoculated birds more than in naive ones. At 1 week old the weight of the inoculated birds was about 64% of the weight of naive ones; at the age of 4 and 6 weeks it was about 74% and 86% respectively. Compensatory growth was most apparent in the inoculated chicks provided with electrolyte solution. At the age of 6 weeks, the latter exceeded the BW of the exclusively water supplied counterparts by 327 g. Electrolyte supplementation up to the age of 3 weeks had no effect on the naive counterparts. Osmolality was reduced slightly, but very significantly by inoculation; electrolyte supply had no effect on this variable. Sodium concentration in the plasma was higher in the inoculated birds. Plasma albumin was markedly reduced by inoculation on weeks 1 and 2. Whereas the inoculated chicks supplied with electrolytes resumed the level plasma albumin level of the naive chicks on week 3, an over-compensation occurred in the inoculated-water-supplied (IW) group, and they surpassed the naive chicks significantly. Blood hematocrit increased significantly with age; inoculation, age and/or electrolyte supplementation had no effect on this variable. Sodium-dependent glucose transport rates were enhanced in vesicles obtained from inoculated chicks as compared to naive ones. While electrolyte supplementation had no effect on glucose active transport in naive chicks, electrolyte supplementation decreased rates of glucose active transport in inoculated ones. These data demonstrate that electrolyte supplementation during the early age may be used to enhance the tolerance of broiler chicks to stunting-syndrome by improving food and water consumption, and subsequently growth rate during and after cessation of electrolyte supply.  相似文献   

11.
The mortality and pathology caused by serotype 4 adenovirus, isolated from chickens with hydropericardium syndrome (HPS) in Japan, was investigated in specific-pathogen-free (SPF) chickens. One-day-old to 15-mo-old SPF chickens were inoculated intramuscularly, orally, and intranasally with liver homogenates from HPS chickens or isolated serotype 4 adenovirus. There were no clinical signs before death. The mortality rate in all groups of 1-day-old chicks was 100%, irrespective of the inoculum or inoculation route. Four-week-old chickens inoculated with liver homogenate also had a 100% mortality rate. Five-week-old chickens inoculated with cell culture of HPS adenovirus had a 40% mortality rate. The mortality rates of 7-mo-old hens inoculated with liver homogenates intramuscularly and orally were 75% and 25%, respectively. In 15-mo-old hens inoculated with liver homogenates intramuscularly, the mortality rate was 70%. Gross lesions were hydropericardium and swelling and congestion of the liver with occasional petechial hemorrhages. Histologically, the liver had diffuse or multifocal hepatic necrosis and hemorrhage with intranuclear inclusion bodies noted within hepatocytes. In the spleen, macrophages containing erythrocytes and yellow pigment were prominent in the red pulp. In the lung, a moderate diffuse macrophage infiltration was noted throughout the lung parenchyma, and these macrophages contained yellow pigment. In the pancreas of the chicks inoculated at 1 day old, there was multifocal necrosis of glands with intranuclear inclusion bodies. Intranuclear inclusion bodies were seen also in the gizzard, proventriculus, duodenum, cecum, kidney, and lung of the chicks inoculated at 1 day old. Immunohistochemically, the intranuclear inclusion bodies of various organs showed positive reactions against group I avian adenovirus. Adenovirus was recovered from the liver of chickens with HPS. This study indicates that HPS adenovirus is able to reproduce HPS lesions and mortality in SPF chicks and even adult chickens and that it is a highly pathogenic strain.  相似文献   

12.
Chicken eggs at embryonation day (ED) 18 or newly hatched chicks were inoculated with turkey herpesvirus (HVT), Marek's disease virus (MDV), or virus-free diluent and, at intervals after inoculation, tissue homogenates of virus-exposed and virus-free chickens or chicken embryos were examined for interferon (IFN) activity. Homogenates of lung, thymus and spleen specimens from chickens given HVT at ED 18 had IFN activity. Activity of IFN in the lungs was studied further. Homogenates of lung specimens from chickens exposed to HVT at hatching also had IFN activity, although the concentration of IFN was lower than that in chickens given HVT at ED 18. The pathogenic isolates of MDV (JM-MDV), but not the attenuated (Md11/75C-MDV) or nonpathogenic (SB1-MDV) isolates, inoculated at ED 18 also induced high lung IFN activity. Exposure to a combination of HVT and SB1-MDV induced IFN activity comparable with that in chickens given HVT alone. The IFN activity in homogenates of lung specimens from virus-exposed chickens was species specific and heat and pH stable, but was destroyed by trypsin treatment. Occasionally, low IFN activity also was detected in homogenates of tissue specimens from virus-free chickens or chicken embryos. This IFN activity could have been produced constitutively or may have been induced by substances (inducers) in the environment.  相似文献   

13.
本试验旨在研究饲粮粗蛋白质水平对济宁百日鸡繁殖性能及初生雏鸡器官指数和血清生化指标的影响,以确定41~48周龄济宁百日鸡饲粮粗蛋白质需要量。采用单因素完全随机试验设计,选用40周龄体重接近、产蛋率无显著差异(P0.05)的健康济宁百日鸡产蛋种鸡525只,随机分为5个处理,每个处理5个重复,每个重复21只鸡。各处理分别饲喂粗蛋白质水平为13%、14%、15%、16%和17%的试验饲粮。预试期7 d,试验期56 d。结果表明:1)饲粮粗蛋白质水平极显著影响了平均日粗蛋白质摄入量(P0.01),平均日粗蛋白质摄入量随着饲粮粗蛋白质水平的增加而增加。2)饲粮粗蛋白质水平显著或极显著影响了种鸡的产蛋总数、种蛋合格数和出雏数(P0.05或P0.01)。3)44周龄种蛋孵化的初生雏鸡,种鸡饲粮粗蛋白质水平仅显著影响了心脏指数(P0.05);48周龄种蛋孵化的初生雏鸡,种鸡饲粮粗蛋白质水平显著影响了小肠指数(P0.05),极显著影响了肝脏指数和血清尿酸含量(P0.01)。综合试验结果,满足41~48周龄济宁百日鸡种鸡最佳繁殖性能的饲粮粗蛋白质水平为14.81%。  相似文献   

14.
Five malabsorption syndrome (MAS) homogenates from The Netherlands and Germany were used to reproduce MAS in broilers. We studied the histopathology after inoculation of 1-day-old broiler chicks and the agents that might be involved. Generally, the MAS homogenates induced signs that differed in severity and pathobiology. We could distinguish and classify the inoculated groups best by histopathology: proventriculitis, lesions in the small intestines in combination with proventriculitis, or lesions of the small intestines only. Lesions in the small intestine had more impact on weight gain depression than lesions in the proventriculus. In three out of five inoculated groups, microscopic lesions of the pancreas were found. Reovirus was detected in the inoculated groups by virus isolation and seroconversion, and reoviral antigen was detected by immunohistochemistry of the small intestine. Also, enteroviruslike particles were detected in three of the five inoculated groups, although not in the most affected group. Additionally, bacteriophages and bacteria (hemolytic Escherichia coli, Pasteurella hemolytica, and Enterococcus durans) were isolated from inoculated chicks. The role these agents play in pathogenesis of MAS is still unsolved.  相似文献   

15.
Ochratoxin A (OA) was administered to 13-day-old chicken embryos via the chorioallantoic membrane. The 7-day LD50 value (day 20 incubation) of OA was calculated at 7.9 micrograms of OA. Ochratoxin-treated embryos (2.5 micrograms) had slight but significant changes in numbers of immunoglobulin-bearing cells in the bursa but not in the spleen. Chicks hatched from in ovo-treated eggs were challenged with 9 X 10(4) colony-forming units (CFU) of beta-hemolytic Escherichia coli (O1:K1) at 7 days of age via the thoracic air sac. Lesion scores of OA-treated chicks were equal to or less severe than those of controls. Hatchmates of the above chicks were vaccinated with a homologous killed E. coli bacterin (O1:K1) at both 2 and 4 weeks of age and challenged with 10(4) CFU of E. coli at 7 weeks. Post-challenge lesions were present in three vaccinated untreated controls and no OA-treated chicks. We conclude that although in ovo exposure to OA may marginally suppress immunoglobulin-bearing cells of bursa, chicks hatched from OA-treated eggs respond as well as controls to an antigen and resist infection by a virulent organism.  相似文献   

16.
Oocysts of an avian isolate of Cryptosporidium were used to inoculate 21 chicks orally and 7 chicks intratracheally to determine the tissue specificity of this organism. Oocysts were passed in the feces 4 to 5 days after inoculation. Oocysts (6.8 by 5.0 microns) were fully sporulated and they were passed for at least 17 days by infected chicks. The mode of inoculation did not influence the distribution of cryptosporidia within the digestive tract. Cryptosporidia were found in the cloaca (100%), bursa of Fabricius (95.7%), terminal portion of the colon (26.1%), and cecum (4.3%) of chicks that were positive for developmental stages. Of 21 chicks inoculated orally, 4 had cryptosporidia in their trachea, whereas 6 of 7 chicks inoculated intratracheally had cryptosporidia in the trachea, bronchi, and air sacs. Cryptosporidium was found in the ducts of the salivary glands and nasal turbinates of chicks inoculated intratracheally that had clinical signs of respiratory tract disease. None of the chicks died or had intestinal disease.  相似文献   

17.
An indirect fluorescent antibody test was developed to detect serum antibody to avian reovirus strain WVU2937. This test employed small multiple well plastic plates (8 x 5.5 cm) which readily fitted into the standard mechanical stage mechanism of an incident light fluorescence microscope. The small wells of the plates required minimal (10 muL) volumes of reagents. In tests on 18 sera in which the indirect fluorescent antibody, agar gel precipitin and plaque reduction methods were compared sera which gave negative results in the agar gel precipitin test were sometimes positive in the indirect fluorescent antibody and plaque reduction test, but indirect fluorescent antibody titers were lower than plaque reduction test titers. No false positive reactions were detected in 46 sera from uninoculated specific pathogen free chicks of up to eight weeks of age.  相似文献   

18.
The major organs and tissues of 24 broiler chickens (70 or 71 days old) suspected of spindle-cell proliferative disease (SPD) because of showing the tumorous lesions distributed throughout the body at meat inspection were collected for histopathological and immunohistochemical examination. Macroscopically, liver, spleen and cecal tonsil showed severe enlargement and white nodules or plaques were observed in the liver, spleen, kidney, intestine and bone marrow of the femur. All chickens were diagnosed with SPD based on the histopathological examination. The lesions of SPD were observed in the liver, spleen, kidney, heart, lung, pancreas, proventriculus, gizzard, duodenum, jejunum, ileum, rectum, cecal tonsil, bursa of Fabricius, bone marrow of the femur and skin. Hemangioma was observed in the lung of 1 bird. Eight 1-day-old specific pathogen-free chicks were inoculated intraperitoneally with 0.25 ml of a 20% homogenate of the affected spleens of three naturally occurring cases. One inoculated bird, necropsied at 10 weeks of age, macroscopically had a white nodule in the kidney and histopathologically had spindle-cell proliferative lesions, a pattern similar to that seen in the naturally occurring cases, in the liver, spleen, kidney, heart, lung, pancreas, proventriculus, duodenum, cecal tonsil and bone marrow of the femur, and was diagnosed with SPD. Immunohistochemically, significant positive reactions with a rabbit antiserum against avian leukosis virus antigens were detected in all spindle cells in the proliferative lesions of all examined SPD cases and in tumor cells of the hemangioma of a field case.  相似文献   

19.
Three virus isolates (WG-3, -4, and -5) from chicks affected by baby chick nephropathy were orally inoculated into 1-day-old specific-pathogen-free chicks of lines PDL-1 and 15I. Additional chicks were orally inoculated with avian nephritis virus (ANV) strain G-4260. Chicks inoculated with isolates WG-3, -4, and -5 died between 2 and 6 days postinoculation (PI), with mortality ranging from 0% to 53.3%. Pathological findings in the dead chicks included nephrosis in chicks inoculated with WG-3, -4, and -5, and nephritis and visceral urate deposition in chicks inoculated with G-4260. The stability of the WG-5 isolate, as well as the size of the particles and the nucleic acid type, were also similar to those of the G-4260 strain. All of the examined chicks inoculated with WG-3, -4, and -5 had interstitial nephritis at 14 days PI. Therefore, the three virus isolates were considered to be ANV. However, there was no serological relationship between the isolates and ANV (G-4260 and M-8 strains).  相似文献   

20.
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