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1.
蛋用型海兰褐母鸡在用网状内皮增生病病毒（REV）细胞适应毒REV-C99（p30）免疫接种后,均在2周内产生REV特异性抗体。来自免疫种鸡的雏鸡在7日龄内100%（10/10）REV母源抗体阳性。分别在有母源抗体和没有母源抗体的1日龄鸡接种与疫苗株同源的低传代毒REV-C99（p3）或异源的REV中国野毒株HA9901（p5）,以此比较母源抗体对同源和异源REV病毒感染造成的免疫抑制的预防作用。结果表明,REV母源抗体能同等有效地预防同源和异源REV感染造成的对H5和H9禽流感灭活疫苗HI抗体反应的抑制作用。  相似文献   

2.
Egg-yolk antibodies induced by immunizing hens with selected Escherichia coli antigens were evaluated for their ability to protect broiler chickens against respiratory/septicemic disease caused by avian pathogenic E. coli (APEC). Seven groups of broiler breeder hens were vaccinated three times, 1 week apart with live E. coli, killed E. coli, E. coli antigens [lipopolysaccharide (LPS), type 1 pilus adhesin (FimH), P pilus adhesin (PapG), aerobactin outer membrane receptor (IutA)] or phosphate buffered saline (PBS). An O78 APEC strain was used for preparation of all the antigens. Egg yolk immunoglobulins (IgY) were purified from eggs of each group and antibody activity in serum and purified IgY was determined by enzyme-linked immunosorbent assay (ELISA). IgY (100mg) was injected intramuscularly into 11-day-old broiler chickens, which were challenged 3 days later with homologous (O78) or heterologous (O1 or O2) E. coli by the intra-air sac route. Mortality was recorded and surviving chickens were euthanized 1 week after the challenge and examined for macroscopic lesions. Passive antibodies against all antigens except FimH were protective (90-100%) against the homologous challenge, but only anti-PapG and anti-IutA were effective against heterologous challenge. Anti-PapG IgY provided the greatest protection against the three serogroups of E. coli used for challenge. Hence vaccination of broiler breeders to induce anti-PapG and anti-IutA antibodies may provide passive protection of progeny chicks against respiratory/septicemic disease caused by APEC.  相似文献   

3.
SUMMARY: Australian lentogenic Newcastle disease viruses were evaluated as uninactivated vaccines in Australian chickens, the response being evaluated by the production of haemagglutination-inhibition (HI) antibodies. Two viruses, V4 and PM9, induced high levels of antibody and were readily transmissible between chickens by contact exposure. Three other viruses were poorly immunogenic and poorly transmissible. Chickens vaccinated intramuscularly with the V4 strain produced higher HI antibody titres than chickens vaccinated by the orotracheal, intranasal and intraocular routes. HI antibody titres in chickens vaccinated with the V4 strain reached peak levels 3 to 5 weeks after vaccination and waned considerably during the next 2 to 4 weeks. However, low levels of HI antibody persisted for at least 36 weeks after vaccination. Intramuscular vaccination with the V4 strain of one-day-old chicks lacking maternal antibody to Newcastle disease virus resulted in 42–70% mortality and the survivors developed very high titres of HI antibody. Similar chickens inoculated orotracheally showed signs of depression and developed high titres of HI antibody, but there were no mortalities. Chickens 1-, 2-, 3- and 4-weeks-old and lacking maternally derived HI antibody to Newcastle disease virus suffered no adverse reaction to intramuscular or orotracheal vaccination. The antibody response of the 1-week-old chickens was considerably poorer than that of the older chickens. Following orotracheal vaccination with the V4 strain, chickens with low levels of maternally derived antibody responded with low levels of HI antibody. On the other hand, in the progeny of hens hyperimmunised with the V4 strain the production of active antibody following orotracheal vaccination was delayed until the level of passive antibody had declined considerably. There was no response to intramuscular vaccination in congenitally hyperimmune chickens. The minimum HI antibody inducing dose of V4 vaccine, when measured 3 weeks after vaccination of 6-weeks-old chickens, was 105.6 50% egg infectious doses.  相似文献   

4.
An enzyme-linked immunosorbent assay (ELISA) was developed to detect antibodies against avian leukosis viruses (ALV), using antigens extracted from Rous-associated virus-inoculated chicken embryo fibroblast (CEF) cells by Nonidet P-40 treatments. The antigens reacted strongly to sera of chickens immunized with antigenically homologous viruses, but weakly to those of chickens immunized with heterologous viruses. Antigens extracted from noninoculated CEF cells by the same procedures did not react to either of the immune sera. Normal control sera did not react to any of the antigens. Reactivities of immune sera were decreased markedly by the sera adsorbing with homologous Rous-associated virus-inoculated CEF cells, but not with heterologous CEF cells. The ELISA-specific optimal doses (the differences between the optimal doses with antigens from ALV-inoculated and noninoculated CEF cells) were correlated strongly with the virus-neutralization titers (r = 0.876, P less than 0.01). Examination of the antibody response from ALV-inoculated chickens revealed that ELISA detected antibodies at the same time or several weeks earlier than did the virus-neutralization test.  相似文献   

5.
A live commercial reovirus vaccine, Enterovax, was administered to adult broiler breeder hens via the drinking water to determine its efficacy in stimulation of circulating antibody. This vaccine was compared with a commercial inactivated reovirus vaccine. Only the inactivated product resulted in increased antibody as measured by a commercial enzyme-linked immunosorbent assay. However, the live reovirus vaccine caused diarrhea in the hens and decreased eggshell quality, fertility, and hatchability. In addition, the live vaccine virus was vertically transmitted from hens to their progeny, resulting in increased embryonic mortality and viral tenosynovitis.  相似文献   

6.
The prevalence of reoviruses in commercial chickens with the runting/stunting syndrome, tenosynovitis, and normal chickens was investigated. Reoviruses were isolated from 3-week-old chickens affected with the runting/stunting syndrome and from older chickens with tenosynovitis; viruses were isolated from tissues with and without lesions. Reoviruses were also frequently isolated from rectal contents of normal 3-week-old chickens, and there was serological evidence of previous reovirus infection in all flocks of adult meat breeder chickens examined. The widespread occurrence of reoviruses in both normal and diseased chickens indicates that the isolation of reoviruses from tissues of chickens with lesions does not necessarily imply any aetiological relationship of reovirus with disease, even in the absence of other known causes. However, the occurrence of reovirus in normal chickens does not preclude an aetiological relationship with disease and further investigation of strain variation and possible virulence factors in avian reoviruses is required.  相似文献   

7.
Protective immunity against avian influenza (AI) can be elicited in chickens in a single-dose regimen by in ovo vaccination with a replication-competent adenovirus (RCA)-free human adenovirus serotype 5 (Ad)-vector encoding the AI virus (AIV) hemagglutinin (HA). We evaluated vaccine potency, antibody persistence, transfer of maternal antibodies (MtAb), and interference between MtAb and active in ovo or mucosal immunization with RCA-free recombinant Ad expressing a codon-optimized AIV H5 HA gene from A/turkey/WI/68 (AdTW68.H5(ck)). Vaccine coverage and intrapotency test repeatability were based on anti-H5 hemagglutination inhibition (HI) antibody levels detected in in ovo vaccinated chickens. Even though egg inoculation of each replicate was performed by individuals with varying expertise and with different vaccine batches, the average vaccine coverage of three replicates was 85%. The intrapotency test repeatability, which considers both positive as well as negative values, varied between 0.69 and 0.71, indicating effective vaccination. Highly pathogenic (HP) AIV challenge of chicken groups vaccinated with increasing vaccine doses showed 90% protection in chickens receiving > or = 10(8) ifu (infectious units)/bird. The protective dose 50% (PD50) was determined to be 10(6.5) ifu. Even vaccinated chickens that did not develop detectable antibody levels were effectively protected against HP AIV challenge. This result is consistent with previous findings ofAd-vector eliciting T lymphocyte responses. Higher vaccine doses significantly reduced viral shedding as determined by AIV RNA concentration in oropharyngeal swabs. Assessment of antibody persistence showed that antibody levels of in ovo immunized chickens continued to increase until 12 wk and started to decline after 18 wk of age. Intramuscular (IM) booster vaccination with the same vaccine at 16 wk of age significantly increased the antibody responses in breeder hens, and these responses were maintained at high levels throughout the experimental period (34 wk of age). AdTW68.H5(ch)-immunized breeder hens effectively transferred MtAb to progeny chickens. The level of MtAb in the progenies was consistent with the levels detected in the breeders, i.e., intramuscularly boosted breeders transferred higher concentrations of antibodies to the offspring. Maternal antibodies declined with time in the progenies and achieved marginal levels by 34 days of age. Chickens with high maternal antibody levels that were vaccinated either in ovo or via mucosal routes (ocular or spray) did not seroconvert. In contrast, chickens without MtAb successfully developed specific antibody levels after either in ovo or mucosal vaccination. These results indicate that high levels of MtAb interfered with active Ad-vectored vaccination.  相似文献   

8.
A fully attenuated apathogenic reovirus vaccine was developed by 235 serial passages of S1133 strain avian reovirus in embryonating chicken eggs and 100 additional passages in chicken embryo fibroblast (CEF) cultures, 65 of which were cultured at 32 C. Chickens with and without maternal antibodies to avian reovirus were vaccinated subcutaneously at 1 day of age and challenged via footpad at 14 days of age. It appeared that the 40th, 66th, and 100th CEF passage levels were apathogenic at doses ranging from 10(2.5) to 10(6.8) TCID50/chick. No gross or microscopic lesions of tenosynovitis developed in vaccinated chicks. Vaccinated chicks were protected against challenge; unvaccinated control chickens were not.  相似文献   

9.
Reoviruses are an important cause of suboptimum performance in commercial broilers worldwide. Integrators use the enzyme-linked immunosorbent assay against the S1133 antigen for monitoring serum of breeders for indicating pullet vaccine success. However, without correlating serology to reovirus challenge, it is difficult to determine whether titers reflect protective immunity. We developed a broiler challenge test against 2 common reovirus isolates (2408 and S1133) to evaluate the efficacy of reovirus pullet vaccine programs. Two reovirus serologic and challenge studies were undertaken using chicks from broiler integrators from the southeastern United States. Breeder flocks, from which the chicks were obtained, received at least 1 live and 2 inactivated reovirus vaccines during their pullet phase. One-day-old progeny were collected from 6 breeder flocks. At 1 d of age, 20 chicks from each broiler flock were bled, and serum was analyzed for antibodies. At 3 to 4 d of age, 20 progeny per flock were challenged with the 2408 reovirus by intratracheal route. At 10 to 14 d of age, another 20 birds per flock were challenged with the S1133 reovirus by footpad. Twenty birds per flock were used as nonchallenged controls. At 3 wk of age, all birds were killed and weighed. Percentage of protection was calculated for each flock based on the absence of gross lesions. Flocks with at least 50% protection were considered well protected. Most flocks were well protected against both viruses. The percentage of protection correlated with day-old enzyme-linked immunosorbent assay titers. Chicks from younger hens had higher titers and the best protection against challenge. Producers, whose hen flocks were monitored herein, were doing a good job of immunizing pullets against reovirus. They are now using reovirus progeny challenge studies along with breeder antibody titers to determine vaccination success of their pullets.  相似文献   

10.
Due to serotype variations among different avian infectious bronchitis viruses isolated in Tunisia since 2000, protection of chicks, especially broiler flocks, with Mass H120 vaccine often fails. Therefore, association of CR88 (793B type) with H120 vaccines was used for better response. Challenge experiments were then conducted to evaluate tracheal and renal cross-protection in chickens immunized via nasal and eye drops. Conferred protection was measured by clinical signs and macroscopic lesions observed, based on scores attributed according to their severities. The results showed a low protection conferred by H120 alone, as vaccination did not reduce tracheal and kidney lesions (70% scored as 3) after TN20/00 virus challenge, which also led to 10% mortality. Conversely, the challenge results indicated that the combination of the 2 strains (H120/CR88) allow high protection. Based on the results of the challenge experiments, a vaccination protocol coupling CR88 to H120 was applied for industrial broiler flocks. Clinical observations and serological results confirmed that association of heterologous serotypes (H120 and CR88 vaccines) increased the levels of protection against infectious bronchitis viruses compared with the H120 vaccine given alone.  相似文献   

11.
Monoclonal antibodies (MAbs) were prepared against avian reovirus S1133 protein sigmaA (esigmaA) synthesized in Escherichia coli. MAbs were characterized and used to develop a diagnostic test. Ten MAbs were selected for competitive binding assay following coupling with horseradish peroxidase. The results indicated that these MAbs delineated two epitopes I and II of esigmaA. An immuno-dot binding assay was used to detect the effect of denaturation on antibody recognition of the epitopes. All MAbs bound to esigmaA in its native form. After denaturation by boiling in SDS and 2-mercaptoethanol, the binding of MAbs recognizing epitope I was fully abolished. However, the reactivity of MAbs recognizing epitope II was not affected. MAbs 31 and 32, recognizing epitopes I and II, respectively, were selected for the cross-reactivity to heterologous reovirus strains. The results suggest that the two epitopes are highly conserved among these virus strains. A MAb capture enzyme-linked immunosorbent assay (ELISA) procedure was developed using MAbs 32 and 31 to detect reovirus protein sigmaA in samples from tendon tissues of infected bird and chicken embryo fibroblast (CEF) cell cultures. Avian reovirus sigmaA antigens in tendon specimens were detected from the inoculated birds as early as 2 days post-inoculation (PI), approximated a peak at 7 days PI, and maintained this until 16 days PI, then decreased gradually. A clear difference in absorbance values between the tendon samples of the avian reovirus- and mock-infected birds is obtained. Positive results were also obtained from avian reovirus-infected CEF and from the tendon tissues of naturally infected broilers. These results indicated that the MAb capture ELISA is a useful methods for the detection of avian reovirus from chickens suspected to have avian reovirus infections.  相似文献   

12.
The object in this investigation was to determine the relationship between protective activity and antigenic structure of Haemophilus paragallinarum, serotypes 1 and 2. A close relationship exists in both serotypes between protective activity and colonial phenotypic form (iridescent and noniridescent). Protective activities of both serotypes were related to a heat-labile, trypsin-sensitive (L) antigen of iridescent form that produced serotype-specific agglutinin to chickens. The chickens having the agglutinins were protected against challenge exposure with homologous strain, but not with heterologous strain. The chickens injected with unencapsulated organisms of noniridescent form that were derived from encapsulated organisms of iridescent form failed to produce both serotype-specific agglutinins and protection against challenge exposure with homologous strain. Most of the chickens injected with serotype 1 strain produced both hemagglutination-inhibition antibody and serotype 1-specific agglutinin, whereas those injected with serotype 2 produced serotype 2-specific agglutinin and protected against homologous challenge exposure. The protective activity was found in saline extract derived from encapsulated organisms of serotype 1, but was absent in those of serotype 2.  相似文献   

13.
Efficacy studies on Haemophilus gallinarum bacterin preparations.   总被引：2，自引：0，他引：2  
Broth cultures inactivated and potentiated by selected methods were tested in chickens for efficacy against homologous and heterologous challenge inoculation, using 2 serotype A strains of Haemophilus gallinarum. Although the 2 strains were within the same serotype, they failed to cross protect. One dose of thimerosal-inactivated bacterin was protective against homologous challenge, but 2 doses of formalin-inactivated bacterin were required. A bivalent bacterin protected chickens well against 1 strain, but not the other, at the 1-dose level.  相似文献   

14.
Coarse-spray (CS) administration of a commercial S1133 reovirus vaccine in chickens for prevention of clinical viral tenosynovitis (VT) infection was evaluated. In Expt. 1, one-day-old specific-pathogen-free (SPF) white leghorns were vaccinated with a combination of reovirus, Newcastle disease (ND), and infectious bronchitis (IB) vaccines by CS and infectious bursal disease vaccine by the subcutaneous (SQ) route. In Expt. 2, one-day-old commercial broilers were vaccinated by CS with reovirus vaccine and Marek's disease (MD) vaccine by SQ. In Expt. 3, one-day-old commercial broilers received reovirus vaccine in combination with ND-IB vaccines at 1 day of age by CS and MD vaccine by SQ. Some birds received an initial or second vaccination at 7 days of age by CS or the drinking-water (DW) route. Birds vaccinated by CS at 1 day of age with reovirus vaccine did not produce circulating virus-neutralizing antibody against reovirus, although they had resistance to VT infection. In contrast, initial or booster vaccination at 7 days of age by CS or DW resulted in an antibody response and greater resistance to challenge than did CS vaccination at 1 day of age. There was no difference in efficacy between CS and DW routes at 7 days of age. The reovirus vaccine did not interfere with other vaccines as measured by serologic (ND-IB-IBD) or challenge (MD) studies.  相似文献   

15.
Marek's disease virus (MDV) vaccines of serotypes 1 and 2 administered in 18-day-old embryonated eggs induced better protection against post-hatch challenge at 3 days with virulent MDV than vaccines given at hatch. Embryonal vaccination with a polyvalent vaccine containing equal quantities of serotypes 1 and 2 of MDV and serotype 3 virus (turkey herpesvirus, HVT) was also significantly more effective than post-hatch vaccination. These and earlier results indicate that protective efficacy of single or combined Marek's disease vaccine serotypes against post-hatch challenge at 3 days can be substantially improved if the vaccines are injected into 18-day embryos rather than at hatch. Injection of vaccines of serotypes 1 or 2 into embryonated eggs or hatched chicks did not cause detectable gross or microscopic lesions in chickens. Vaccine viruses of serotypes 1 and 2 could be isolated from spleen cells of chickens 1 week post-vaccination, and the titer of recoverable viruses was higher in chickens that received the vaccines at the 18th day of embryonation than in chickens vaccinated at hatch. Although embryo vaccination with HVT usually provided better protection than post-hatch vaccination against early post-hatch challenge with variant pathotypes of MDV, the protection was poor regardless of vaccination protocol. If challenge with variant pathotypes of MDV was delayed until embryonally or post-hatch HVT-vaccinated chickens were 21 days of age, protection of chickens by HVT was not enhanced. Thus, resistance induced by embryonal vaccination with HVT was qualitatively similar to that induced by post-hatch vaccination with this virus.  相似文献   

16.
Eight poultry farms in Nigeria, including chickens from nine breeder, 14 broiler, 28 pullet, 11 layer, and three cockerel flocks, were tested for antibody seroprevalence to the following poultry viruses of potential economic importance: infectious bronchitis virus (IBV), avian reovirus, avian pneumovirus (APV), infectious laryngotracheitis virus (ILTV), avian influenza virus (AIV), and avian leukosis virus (ALV). Serum samples were collected between 1999 and 2004 and were tested for antibodies using commercial enzyme-linked immunosorbent assay (ELISA) kits. Seroprevalence was very high for IBV (84%); intermediate for reovirus (41%), APV (40%), and ILTV (20%); and very low for ALV (<5%) antibodies. By commercial ELISA, the seroprevalence of antibodies against AIV was, in some flocks, up to 63%. However, more specific assays did not confirm AIV antibodies, indicating that all flocks tested were free of avian influenza antibodies. Birds seemed to be first infected by IBV (at about 7 wk of age), then by reovirus at 12 wk, before they became infected by APV (week 25) and ILTV (week 30). This is the first report of serological evidence of the above viruses in West Africa. Further studies are necessary to assess economic losses due to these avian viruses and the costs and benefits of countermeasures.  相似文献   

17.
Pathogenicity for chickens of a reovirus isolated from turkeys   总被引：1，自引：0，他引：1  
A viral agent that was isolated from livers of commercial turkey poults that died at approximately two weeks of age was characterized as a reovirus. Experimental infection of day-old chickens with this reovirus isolate resulted in the development of tenosynovitis, hepatitis, and myocarditis. In vitro neutralization of the turkey reovirus isolate by antiserum against chicken reovirus correlated with in vivo protection of maternally immune chickens from day-old oral challenge with the turkey reovirus isolate.  相似文献   

18.
Because it is expected to induce cross-reactive serum and mucosal antibody responses, mucosal vaccination against highly pathogenic avian influenza (HPAI) is potentially superior to conventional parenteral vaccination. Here, we tested whether intraocular vaccination with an inactivated AI virus induced protective antibody responses in chickens. Chickens were inoculated intraocularly twice with 104 hemagglutination units of an inactivated H5N1 HPAI virus. Four weeks after the second vaccination, the chickens were challenged with a lethal dose of the homologous H5N1 HPAI virus. Results showed that most of the vaccinated chickens mounted positive antibody responses. The median serum hemagglutination inhibition titer was 1:80. Addition of CpG oligodeoxynucleotide 2006 or cholera toxin to the vaccine did not enhance serum antibody titers. Cross-reactive anti-hemagglutinin IgG, but not IgA, was detected in oropharyngeal secretions. In accordance with these antibody results, most vaccinated chickens survived a lethal challenge with the H5N1 HPAI virus and did not shed the challenge virus in respiratory or digestive tract secretions. Our results show that intraocular vaccination with an inactivated AI virus induces not only systemic but also mucosal antibody responses and confers protection against HPAI in chickens.  相似文献   

19.
A commercial reovirus vaccine alone or experimental reovirus vaccine plus antibody complex were inoculated into 18-day-old specific pathogen free (SPF) broiler embryos at 0.1 of the recommended chick dose. The following groups were used: group 1A was not vaccinated or challenged; group 1B was not vaccinated, but was challenged with virulent reovirus; group 2 received the vaccine complexed with 1/4 dilution of antiserum; group 3 received the vaccine with 1/8 dilution of antiserum; group 4 received the vaccine with 1/16 dilution of antiserum, and group 5 received vaccine alone. At 1, 3, 6, 9, and 12 days of age, serum was collected and antibody against avian reovirus was analyzed by enzyme-linked immunosorbent assay (ELISA). At the same times, spleens were collected and vaccine virus detected by inoculating chicken embryo fibroblasts (CEFs) and examining for cytopathic effect. At 15 days of age, chickens in groups 2-5 were challenged with reovirus. At 22 days of age, birds were euthanatized and weighed. Efficacy of the vaccines was based on safety, percent protection, and antibody response. In ovo vaccination with the commercial or experimental vaccines did not adversely affect hatchability of SPF chickens. The vaccine complexed with antibody resulted in significantly less posthatch mortality (3.7%) when compared to mortality of chickens that received vaccine alone (17%). Both vaccine virus recovery and antibody response were delayed at least 3 days in birds receiving the experimental vaccines. In evo administration of reovirus antibody complex vaccines provided at least 70% protection. The experimental reovirus-antibody complex vaccines were safe and efficacious when given in ovo to SPF broiler embryos.  相似文献   

20.
A region of genome from the NADL strain of BVDV corresponding to the coding sequence for the E2 glycoprotein has been molecularly cloned using RT-PCR. The viral cDNA sequence was used to construct vaccinia virus recombinants that expressed either the entire E2 coding sequence or fragments of it. These recombinants were used to immunise mice of three H-2 haplotypes to investigate their ability to elicit a neutralising antibody response against BVDV. Sera from mice immunised with the recombinant expressing full length E2 contained high levels of virus neutralising antibodies that in addition to giving neutralisation of the homologous NADL strain were also able to neutralise the Oregon C24V reference strain. These sera failed to give any neutralisation of the Osloss reference strain providing evidence for the division of BVDV isolates into at least two distinct E2 serotypes. These results were confirmed in gnotobiotic lambs. Expression of E2 fragments revealed the presence of at least two distinct neutralising epitopes, one of which was localised within the carboxy terminal 90 amino acids of the protein.  相似文献   

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