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1.
In the progeny of breeder birds which had been vaccinated with live Salmonella Typhimurium and inactivated Salmonella Enteritidis vaccines, the caecal and systemic colonisation by a live Salmonella Enteritidis and a live Salmonella Typhimurium vaccine was studied. The efficacy of the oral immunisation of chicks from vaccinated and non-vaccinated breeders with a live Salmonella Enteritidis vaccine on day 1 of age was studied by an experimental challenge with Salmonella Enteritidis on day 30 of age. Antibody production of isotypes IgG, IgA and IgM was determined in sera and jejunum of the birds. Vaccination of parent birds resulted in an increase of the antibody concentration in sera and jejunum of the chicks. Own antibody production after administration of the live Salmonella vaccine to the day-old chicks was not detected until day 21 of life. Compared to controls, the number of vaccine organisms in the caeca of the progeny of vaccinated breeder birds was reduced by 0.5-1.5 log10 units. The reduction of the Salmonella Enteritidis vaccine was more pronounced than that of the Salmonella Typhimurium vaccine. However, the reduced colonisation by the live Salmonella vaccine strain did not impair the efficacy of the immunisation of the chicks. To ensure efficacy of the active oral immunisation of chicks from vaccinated parent birds with attenuated live Salmonella vaccines also in case where amounts of maternally transferred antibodies are even higher, it should be guaranteed that chicks take in via drinking water the recommended dose of the vaccine strain. In this connection, factors like the low intake of drinking water by very young chicks, the concentration of the vaccine organisms in the water and the survival of the vaccine should also be considered.  相似文献   

2.
Eighteen chickens were immunized subcutaneously with purified type 1 fimbriae from Salmonella enterica serotype Enteritidis at 18 and 21 weeks of age. Evidence of IgG and IgA responses was found in the eggs and in the sera of the immunized hens. Three weeks later, immunized and non-immunized chickens (n=18) were challenged intravenously with 2x10(7) live Salmonella enterica serotype Enteritidis. There was no significant difference in the numbers of eggs laid by immunized and non-immunized birds. The percentage of Salmonella contaminated eggs was significantly higher in the non-immunized group than in the immunized group due to a higher percentage of contamination of the externally disinfected egg shells. There were no statistical differences in the percentages of contaminated yolks and egg whites between control and immunized birds. No differences in the number of colonizing bacteria could be found in the spleen nor in the liver between the immunized and the control groups throughout the experiment. Salmonella was cleared from the ovary of the immunized birds in the second week p.i., in contrast to the control birds where Salmonella was isolated till the third week after infection. Oviducts were significantly more infected in the control group than in the immunized group. Salmonella was cleared from the oviducts at 3 weeks p.i. in the immunized hens but not in the control hens. In conclusion, we demonstrated that the immunization of laying hens with type 1 fimbriae reduced the number of contaminated eggs and reduced the colonization of the reproductive organs.  相似文献   

3.
In the chicken, maternal antibodies are transferred into the egg and subsequently transported into the developing embryo. IgG (called IgY) is the primary immunoglobulin isotype of the egg yolk. Their level in serum depends on the correct function of immunological system in laying hens. Many factors have a direct or indirect influence on antibody level in fowl. One of them is a commonly used antibiotic, but its influence on avian immune system is still unknown. The objective of the study was to determine the effect of enrofloxacin and chloramphenicol on the level of IgY antibody in serum and egg yolk after immunostimulation of hens with living cells of Salmonella enterica subsp. enterica serovar Enteritidis and lipopolisaccharide. Forty adult egg-laying Arbor Acres and Isa 215 hens (32 and 50 weeks old) from the reproductive flocks and 1640 of their eggs were used for the investigation. No clinical symptoms of any diseases were observed in birds during the entire breeding period. Additionally the birds were checked as free from Salmonella spp. in the beginning of the experiment. The birds were divided into 6 experimental and 2 control groups (5 birds in one group). The hens in the experimental groups were immunized with S. Enteritidis antigens: living bacteria and lipopolisaccharide and treated with enrofloxacin or chloramphenicol. Antibiotics were administered in drinking water for 10 days (from 3rd to 13th day of experiment). To indicate anti-S. Enteritidis, antibodies in sera and egg yolk were used indirectly on ELISA based on lipopolisaccharide from S. Enteritidis. As conjugate these were applied anti-chicken IgY with horseradish peroxidase and ABTS with H2O2 as obtained. Additionally, to detect antibody in serum, a rapid slide test was used with Pullognost and Enterognost standard antigens made in the laboratory. The study revealed that both antibiotics tested decreased the level of specific IgY in laying hens immunized with living bacteria and lipopolisaccharide. It seems that antibiotics have a suppressive effect on the immunological system. The strongest immunosuppressive effect was exerted by chloramphenicol.  相似文献   

4.
Pang Y  Wang H  Li Z  Piao J  Piao J  Chi Y  Jin J  Liu Q  Li W 《Avian diseases》2012,56(2):347-353
In order to generate Salmonella enterica serovar Enteritidis fimbriae antigens (rSEF21), the intact region encoding SEF21 was amplified from Salmonella Enteritidis by PCR and subcloned into a prokaryotic expression vector pET-28a(+) to yield pET-28a(+)-SEF21. The rSEF21 protein was highly expressed and purified by nickel affinity chromatography. Liposomeassociated rSEF21 was prepared for oral immunization to seek protective efficacy for intestinal infection with Salmonella Enteritidis. Evidence of IgA and IgG responses were found in the intestinal tracts and in the sera of a group of chickens immunized. Two weeks after the booster immunization, the chickens were challenged orally with 2 x 10(6) colony-forming units of live Salmonella Enteritidis, and fecal samples were examined for bacterial excretion from the intestinal tract. Significantly less fecal excretion of bacteria was observed in immunized chickens for 4 wk after challenge. The numbers of bacteria in the intestinal contents (cecum and rectum) were also significantly lower in immunized chickens than in unimmunized controls. Therefore, oral immunization with liposome-associated rSEF21 elicits both systemic and mucosal antibody responses, leading to a reduction in bacterial colonization in the intestinal tract and excretion of Salmonella Enteritidis in the feces.  相似文献   

5.
Forty layer farms from 2 states participated in a study to examine the risk factors and incidence of Salmonella Enteritidis from multiple samples, including environmental drag swabs from the bird areas, feed, water, flies, rodents, live rodent traps, and environmental swabs from areas occupied by other livestock. Twenty-four of these farms had between 3,000 and 31,000 bird flocks (medium-sized flocks) and 16 had less than 3,000 birds (small-sized flocks). All were housed in cage-free production systems. Twenty-two farms included outside pasture areas for the birds. Most of the participants had just come under the FDA Egg Rule and had not yet tested their flocks (flocks under 3,000 birds are exempt) for Salmonella Enteritidis. Many, however, obtained their pullets from commercial Salmonella Enteritidis-clean breeder sources hatched in National Poultry Improvement Plan hatcheries. Vaccination against Salmonella Enteritidis was performed on 21 of the 40 farms (combination of live and killed vaccines). Salmonella Enteritidis was detected on 7 out of the 40 farms, primarily in rodents, their feces, or from swabs taken inside live traps. Of these 7 Salmonella Enteritidis-positive farms, 3 farms that had vaccinated their pullets with live Salmonella Typhimurium vaccine and killed-Salmonella Enteritidis vaccine; no Salmonella Enteritidis was isolated from the environmental drag swabs taken from the bird area or from the eggs on these farms. However, on the farms that had not vaccinated for Salmonella Enteritidis, the organism was isolated from 4 environmental drag swabs and 3 egg pools. The last 4 farms had flocks under 3,000 birds. No Salmonella Enteritidis was isolated from any of the samples of feed, flies, water, or swabs taken from other livestock areas. Based on the initial findings in this study, we suggest the 2 most important risk factors for Salmonella Enteritidis contamination inside the bird area and in the eggs in these small- and medium-sized flocks are the presence of infected rodents and the absence of an Salmonella Enteritidis vaccination program.  相似文献   

6.
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   

7.
Fifty cases submitted between 2000 and 2002 were selected for retrospective analysis to evaluate possible relationships between Salmonella arizonae isolated from breeder flocks, hatching eggs, and meat bird flocks belonging to a single turkey integrator. In all the meat bird cases selected for this study, arizonosis was the primary diagnosis. In birds under 1 month of age, clinical signs and pathologic changes were observed in older birds. The Salmonella arizonae isolates were analyzed by antibiotic resistance pattern and serotype and genotyped by pulsed-field gel electrophoresis (PFGE). Serotyping and PFGE yielded similar results, but the antibiotic resistance patterns did not correspond to either serotyping or PFGE typing. The presence of common pulsed-field patterns in breeder flocks, eggs, and meat bird flocks suggested that S. arizonae was being transmitted vertically from the breeder flock.  相似文献   

8.
The purpose of this work was to develop a live, attenuated vaccine strain to protect chickens against colonization by group C Salmonella. We constructed two candidate vaccines: a deltacya deltacrp derivative and a deltaphoP derivative of Salmonella hadar. White Leghorn chickens were vaccinated at day of age and at 2 wk with one of the two strains. A nonvaccinated group served as a control. At 4 wk of age, all birds were challenged with wild-type S. hadar and necropsied 6 days later. Numbers of S. hadar in the ceca were determined. Enzyme-linked immunosorbent assay-derived serum immunoglobulin G responses against S. hadar lipopolysaccharide indicated that both strains induced a serum antibody response. The average optical density450 for birds vaccinated with the deltaphoP or deltacya deltacrp derivatives was 0.456 and 0.881, respectively. Although the deltacya deltacrp derivative induced higher levels of serum antibody, it did not provide an immune response protective against colonization by S. hadar. Conversely, birds vaccinated with the deltaphoP strain showed significant protection against S. hadar challenge. Seventy percent of the nonvaccinates, 60% of the deltacya deltacrp vaccinates, and 15% of deltaphoP vaccinates were positive for S. hadar in tissues. In a second experiment, birds were vaccinated with either the deltaphoP strain or buffer and challenged with a 10-fold higher dose than in the first experiment. After challenge, all of the birds in both groups were colonized. The geometric mean number of cecal S. hadar isolated from the control group was 1.0 x 10(6) colony-forming units (CFU)/g, and from the vaccinated group, this value was 32 CFU/g, indicating a four to five log reduction in colonization by the challenge strain.  相似文献   

9.
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10.
The Paul Ehrlich Institute, Langen, in Germany has been licensed different live vaccines of S. Typhimurium and S. Enteritidis for use in the veterinary medicine since I the 90s. The Robert Koch Institute has established a lab-based surveillance system for these live vaccine strains for an evaluation of recent public health safety. Since 2000 all strains of S. Typhimurium and S. Enteritidis from humans were investigated in respect to their phage types and other vaccine markers. 3676 S. Typhimurium strains and 4489 S. Enteritidis strains mainly from Salmonellose patients were investigated after phage typing according to their auxotrophic or antibiotic resistance markers. The live vaccine strains of Zoosaloral, TAD Salmonella vacT or TAD Salmonella vacE and Salmovac SE could not be found from infections in humans.  相似文献   

11.
Salmonella reduction in broilers from commercial broiler breeders vaccinated with live and killed Salmonella vaccines was evaluated. Broiler breeders were vaccinated with Poulvac ST live Salmonella Typhimurium vaccine at 1 d of age, and this was repeated at 2 and 6 wk of age. The breeders were then administered a killed autogenous oil emulsion adjuvanted vaccine containing Salmonella Kentucky, Salmonella Heidelberg, and Salmonella Hadar, at 10 and 18 wk of age. From the ages of 36 to 52 wk, eggs from the breeder flock were hatched, and progeny were challenged in 4 separate experiments at 1 d of age by oral gavage with 1 × 106 cfu/chick by either Salmonella Kentucky, Salmonella Heidelberg, Salmonella Hadar, or Salmonella Enteritidis, each containing resistance to naladixic acid at 32 μg/mL. At 17 to 21 d of age, the broilers were euthanized, and 1 side of the cecum was cultured for Salmonella, and the other side of the cecum was used for enumeration on positive samples. Recovered Salmonella was confirmed to be the challenge strain by O-antisera grouping. This study indicated a difference in Salmonella incidence and enumeration between the vaccinated and nonvaccinated breeder groups for certain species. When challenged with serotypes Salmonella Kentucky, Salmonella Hadar, and Salmonella Heidelberg, protection was noted with a reduction of 28, 17, and 11%, respectively, when compared with the control groups. However, protection was not seen when challenged with S. enteritidis. Under the conditions of this study, live and killed vaccination of commercial broiler breeders with Salmonella contributes protection to progeny when challenged at 1 d of age.  相似文献   

12.
Avian necrotic enteritis is a major economic and welfare issue throughout the global poultry industry and is caused by isolates of Clostridium perfringens that produce NetB toxin. Previously we have shown that birds directly vaccinated with inactivated C. perfringens type A culture supernatant (toxoid) combined with recombinant NetB (rNetB) protein were significantly protected from homologous and heterologous challenge. In the present study the protective effect of maternal immunization was examined. Broiler breeder hens were injected subcutaneously with genetically toxoided rNetB(S254L) alone, C. perfringens type A toxoid and toxoid combined with rNetB(S254L). Vaccination resulted in a strong serum immunoglobulin Y response to NetB in hens immunized with rNetB(S254L) formulations. Anti-NetB antibodies were transferred to the eggs and on into the hatched progeny. Subclinical necrotic enteritis was induced experimentally in the progeny and the occurrence of specific necrotic enteritis lesions evaluated. Birds derived from hens immunized with rNetB(S254L) combined with toxoid and challenged with a homologous strain (EHE-NE18) at either 14 or 21 days post-hatch had significantly lower levels of disease compared to birds from adjuvant only vaccinated hens. In addition, birds from hens immunized with rNetB(S254L) alone were significantly protected when challenged at 14 days post-hatch. These results demonstrate that maternal immunization with a NetB-enhanced toxoid vaccine is a promising method for the control of necrotic enteritis in young broiler chickens.  相似文献   

13.
In this study, a genetically engineered live attenuated Salmonella Enteritidis (SE) vaccine was evaluated for its ability to protect against Salmonella Typhimurium (ST) infection in chickens. The birds were orally primed with the vaccine on the 1st day of life and given an oral booster at 5 wk of age. Control birds were orally inoculated with phosphate-buffered saline. Both groups of birds were orally challenged with a virulent ST strain at 9 wk of age. Compared with the control chickens, the vaccinated chickens had significantly higher levels of systemic IgG and mucosal IgA against specific ST antigens and a significantly greater lymphoproliferative response to ST antigens. The excretion of ST into the feces was significantly lower in the vaccinated group than in the control group on days 9 and 13 d after challenge. In addition, the vaccinated group had significantly fewer pronounced gross lesions in the liver and spleen and lower bacterial counts in the internal organs than the control group after challenge. These data indicate that genetically engineered live attenuated SE may induce humoral and cellular immune responses against ST antigens and may confer protection against virulent ST challenge.  相似文献   

14.
A commercial inactivated iron restricted Salmonella Typhimurium and Salmonella Enteritidis vaccine was used to vaccinate chicks at 1 day and again at 4 weeks of age, with challenge by a high and a low dose of S. Typhimurium given either orally or by contact with seeder birds inoculated orally with a high dose of S. Typhimurium. In all three challenge regimes, the shedding of challenge strain was reduced significantly (p < 0.05) in vaccinated birds compared with unvaccinated controls. Vaccination reduced colonisation of internal organs after challenge by contact seeder birds. However, no effect of vaccination upon colonisation of internal organs after either high or low oral challenge was apparent. In conclusion, the data indicate that the vaccine should be a useful tool in the control of S. Typhimurium infection in chickens.  相似文献   

15.
In the last 2 decades, the prevalence of Salmonella enterica serotype Enteritidis (Salmonella Enteritidis) has dramatically increased worldwide, becoming the leading cause of food-borne illnesses and an important public health issue. Many studies have suggested the role of the SEF14 fimbrial protein in the adhesion of Salmonella Enteritidis to the host. In the present study, the sefA gene, which encodes the main subunit of the SEF14 fimbrial protein, was cloned into a temperature-sensitive expression vector and transformed into a nonpathogenic, avirulent strain of Escherichia coli. The recombinant strain was used as a vaccine to elicit specific immune response against the SefA protein of Salmonella Enteritidis in 1-day-old chickens. The recombinant strain was reisolated from the intestines of treated birds for up to 21 days posttreatment, demonstrating its ability to colonize the intestinal tracts of 1-day-old chickens. In addition, immunoglobulin A (IgA) against the SefA protein was detected in intestinal secretions from treated birds at 7 days posttreatment and in bile samples from 14 to 21 days posttreatment by enzyme-linked immunosorbent assay. Nontreated birds did not show any evidence of intestinal colonization by the recombinant strain or anti-SefA IgA response in their bile or intestinal secretions. Preliminary evaluation of the recombinant strain showed a potential use of this strain to elicit protection against Salmonella Enteritidis infection in chickens. Further experiments are needed to study the ability of the recombinant strain to protect birds against Salmonella Enteritidis colonization.  相似文献   

16.
The humoral and cell-mediated immune (CMI) response to 2 commercial killed Salmonella Enteritidis (SE) vaccines (Layermune and MBL SE4C) was evaluated in laying hens. Layers were distributed in 2 experimental groups. The first received a single immunization at 16 wk of age, while the second experimental group was immunized at 12 wk of age and again at 18 wk of age. Serum immunoglobulin (Ig)G antibodies were measured using a commercial SE ELISA kit and showed persistent levels from 3 to 32 and 34 wk post-vaccination. The vaccination protocol using 2 immunizations showed a higher seroconversion level than the single vaccination. However, our results for bacterial intracellular survival indicated that IgG titers were not linked with bacterial killing. Local IgA production was measured in the intestines and oviducts with an in-house SE whole cell antigen ELISA. Only the MBL SE4C vaccine elicited IgA antibody production when tested on intestine and oviduct mucosal secretions, 3-weeks post-vaccination in both immunization protocol groups. To evaluate the CMI response, the splenic T-cells and B-cells populations were analyzed using flow cytometry. The CD3/B-cell ratio decreased 3 wk after the second immunization in the twice vaccinated Layermune group due to an increase in B-cells.  相似文献   

17.
Vaccination of broiler breeder parents with live infectious bursal disease (IBD) vaccine by the oral route resulted in higher and more persistent quantitative gel diffusion precipitins than vaccination by intramuscular injection. All the progeny of the orally vaccinated parents had maternally derived IBD antibody (MDA) at hatching while MDA was detected in only 35 per cent of the progeny of the intramuscularly vaccinated parents. This MDA had disappeared completely at 14 and eight days respectively. Susceptibility to IBD challenge began at eight days in the first group and at one day old in the second. The age of 100 per cent susceptibility occurred at 19 and 11 days in the respective groups.  相似文献   

18.
To evaluate the efficacy of a novel attenuated Salmonella Enteritidis (△lon△cpxR) vaccine candidate (JOL919), chickens were immunized through oral and intramuscular routes to reduce egg contamination against S. Enteritidis challenge. Birds were orally immunized with JOL919 on the first day of life and were subsequently boosted in the 6th and 16th weeks through oral (group B) or intramuscular (group C) route, while control birds were unimmunized (group A). The chickens of all groups were challenged intravenously with the virulent S. Enteritidis strain in the 24th week. The immunized groups B and C showed significantly higher plasma IgG and intestinal secretory IgA levels as compared to those of the control group. The lymphocyte proliferation response and CD45+CD3+ T‐cell number in the peripheral blood of the groups B and C were significantly increased. In addition, the egg contamination rates were significantly lower in the group B (0%, 10.7% and 0%) and the group C (3.6%, 14.3% and 3.6%) as compared to the group A (28.6%, 42.8% and 28.6%) in the 1st, 2nd and 3rd weeks post‐challenge. All animals in the groups B and C showed lower organ lesion scores in the liver and spleen and lower bacterial counts in the liver, spleen and ovary at the 3rd week post‐challenge. These results indicate that this vaccine candidate can be an efficient tool for prevention of Salmonella infections by inducing protective humoral and cellular immune responses. In addition, this vaccine did not prevent egg contamination, but did appear to reduce incidence. Booster immunizations, especially via oral administration route, showed an efficient protection against internal egg contamination with S. Enteritidis.  相似文献   

19.
To use the advantages of both the competitive exclusion (CE) technique and immunization with a live Salmonella vaccine, the combination of these methods was studied. Specific-pathogen-free chickens were pretreated by combined or single administration of a CE culture and a commercial live Salmonella typhimurium vaccine on days 1 and 2 of life and challenged with Salmonella typhimurium on day 3 to study the exclusion effect by both the CE preparation and the Salmonella vaccine. The exclusion effect by the CE culture combined with the immunologic effect by the live vaccine was studied after challenge of the birds on day 43 of age. The number of challenge organisms in ceca was used to evaluate the efficacy of the pretreatment. The protective exclusion effect of the CE culture was substantial in very young chicks and still detectable in 6-wk-old birds. The attenuated Salmonella typhimurium vaccine produced only an initially occurring exclusion effect. Because the exclusion effect of the CE culture was considerably stronger than the exclusion effect of the attenuated Salmonella typhimurium vaccine, the combination of both did not result in an additive protective effect. In order to exploit the exclusion potential between Salmonella strains and to attain an additive exclusion effect by a CE culture and a vaccine strain, live Salmonella vaccines are needed that are sufficiently attenuated without affecting genes essential for colonization exclusion of other Salmonella organisms. In 6-wk-old birds, the exclusion effect by the CE culture combined with the immunologic effect by the live Salmonella vaccine resulted in a degree of protection considerably beyond that generated by the exclusive use of the two methods. The administration of the live Salmonella vaccine strain prior to or simultaneously with the CE culture revealed the best protective effect because such combinations ensure an adequate persistence of the vaccine strain as prerequisite for the expression of an exclusion effect in very young chicks and the development of a strong immune response affording protection in older birds.  相似文献   

20.
Previous findings, viz. that mice can be successfully immunized against infection with Salmonella dublin with either live or inactivated vaccine, were confirmed. Immunity lasted for at least 12 weeks in mice which had been immunized with inactivated alum-precipitated vaccine. The immunogenicity of inactivated vaccine gradually decreased on storage at 4 degrees C, but this was only detectable if a single injection was used for immunization: 2 injections virtually eliminated this phenomenon. The immunogenicity of live vaccine in mice was not enhanced by levamizole or the simultaneous injection of inactivated organisms. Both live and inactivated vaccines provided immunity in calves. A single injection of lyophilized vaccine, prepared from live rough Salmonella dublin strain (HB 1/17),protected 3 out of 6 calves, while 2 injections of a formalin-inactivated, alum-precipated vaccine, containing 1% packed cells of S. dublin strain 2652 V, protected 5 out of 6 calves against intraduodenal challenge with 2 x 10(9), S. dublin strain 2652 V. Two calves which had been immunized with an inactivated oil adjuvant vaccine were also solidly immune to this challenge. Serum antibody response in calves was poor when measured by the tube agglutination and the haemagglutination tests. Similarly, the sera had only marginal protective values when tested by means of a passive protection test in mice. Antibody titres alone are not a valid measure therefore, for the immune status of immunized animals.  相似文献   

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