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1.
Immunogenicity of and protection afforded by Pasteurella haemolytica bacterins were studied in calves. Bacterins contained an aluminum hydroxide in gel (ALH) adjuvant or one of the following oil-in-water adjuvants: Freund's complete adjuvant (FCA), Freund's incomplete adjuvant (FIA), and trehalose dimycolate (TDM). On days 0 and 7, calves were vaccinated with phosphate-buffered saline solution (PBSS), a bacterin, or live P haemolytica. Transthoracic intrapulmonic challenge exposure was done on day 21. In 3 experiments, there were no significant (P greater than 0.05) differences between lung lesions induced in PBSS-or ALH bacterin-vaccinated calves. Both FCA and FIA bacterins significantly (P less than 0.05) enhanced resistance against challenge exposure. Resistance induced by FCA and FIA bacterins was comparable with that induced by vaccination with live P haemolytica. Calves vaccinated with FIA bacterin and challenge-exposed to P haemolytica at a concentration of 4.5 X 10(9) colony-forming units (4.5 times greater than used in the first 3 experiments) resisted challenge exposure similar to calves given live organisms. The TDM bacterin failed to enhance resistance. All bacterins caused a significant increase (P less than 0.05) in serum antibody to P haemolytica somatic antigens, as measured by a quantitative fluorometric immunoassay. Pasteurella haemolytica leukotoxin neutralizing antibody titers did not increase significantly (P greater than 0.05) in sera after vaccination with any bacterin. Vaccination with FCA and FIA bacterins resulted in a significant increase (P less than 0.001) in serum antibody to a carbohydrate-protein subunit of P haemolytica, as measured by an enzyme-linked immunosorbent assay.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

2.
Using 6- to 8-month-old beef calves, 3 experiments were conducted to compare the effect of vaccination with live or killed Pasteurella haemolytica on resistance to a transthoracic challenge exposure with the organism and to correlate serum antibody response with resistance. In each experiment, calves were vaccinated twice at 1-week intervals and were challenge exposed 21 days after the first inoculation. Lung lesions were evaluated by a system, such that higher scores indicated the more severe lesions. In each experiment, calves immunized with live P haemolytica had lower lesion scores than calves vaccinated with saline solution or bacterin. In 2 of the experiments, the differences were significant (P less than 0.05). In all experiments, calves vaccinated parenterally with a commercial P haemolytica/P multocida bacterin or with a formalin-killed P haemolytica bacterin had lesion scores that were not significantly different (P greater than 0.05) than for control calves vaccinated with saline solution. Live and killed bacterial preparations induced a significant serum antibody response to P haemolytica as measured by a quantitative fluorometric immunoassay. The antibody response to vaccination was not affected by preexisting titers to P haemolytica. Serum antibody titers were not consistently as high for calves vaccinated with bacterins as for calves vaccinated with live organisms. Although high antibody titers correlated with low lesion scores when calves vaccinated with saline solution or live organisms were analyzed collectively, there was not a significant correlation between the 2 variables when calves, vaccinated with saline solution or with bacterin, were analyzed collectively. These data indicate that, although bacterins may induce a detectable serum antibody response, they do not induce protection against transthoracic challenge exposure to P haemolytica.  相似文献   

3.
Porcine herpesvirus 1 (PHV-1) antigens were extracted from virus-infected cells using the nonionic detergent Triton X-100. A single vaccination with these viral antigens in Freund's incomplete adjuvant resulted in the production of neutralizing antibody and a cellular immune response in mice. An 87% rate of protection was observed in these mice upon challenge with a lethal dose of PHV-1. A second vaccination given at day 21 resulted in higher levels of neutrilizing antibody and 100% protection of vaccinated mice upon challenge with virulent PHV-1.  相似文献   

4.
The protective effect of an inactivated Mycoplasma gallisepticum (MG) bacterin was evaluated in chickens subsequently challenged intratracheally (IT) with the homologous strain. Antibody responses in sera and tracheal washings (TWs) from these chickens were determined by an enzyme-linked immunosorbent assay. A group of chickens was vaccinated intramuscularly (IM) with two doses of the bacterin containing aluminum hydroxide gel (IM + IM). Another group was vaccinated IM with the same bacterin followed by IT with bacterin lacking the adjuvant (IM + IT). Chickens of both vaccinated groups had similar levels of antibody in TWs at the time of challenge. MG was eliminated from the trachea at higher rates and inflammatory lesions in the trachea were less severe in vaccinated chickens than in unvaccinated controls. The protective effect in chickens vaccinated IM + IT was greater than that in chickens vaccinated IM + IM. Perhaps vaccinal immunity is mediated by local rather than systemic antibody responses, or perhaps resistance provided by vaccination IM + IT is conferred partly by another immune mechanism such as cell-mediated immunity.  相似文献   

5.
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   

6.
Oesophagostomum radiatum, the nodular worm of cattle, is a severe pathogen in previously uninfected calves. However, cattle develop a strong protective immune response upon exposure to the parasite. In order to evaluate whether soluble parasite antigens could induce protective immunity, a soluble fraction was obtained from disrupted adult worms, and this fraction was used to vaccinate calves. The vaccination protocol involved two immunizations. The first was administered intramuscularly with complete Freund's adjuvant, the second was given intraperitoneally with antigen plus alum. This immunization reduced the number of worms developing from a subsequent challenge infection by 85% and also reduced clinical signs associated with infection with adult worms. However, vaccination resulted in decreased weight gains during the larval phase of the infection. Analysis of the immune response generated in the vaccinated calves indicated that protection from infection was significantly correlated with the levels of: (1) circulating parasite-specific IgG2 antibody; (2) cellular immune reactivity as determined in a conventional parasite-specific lymphocyte proliferation assay. Serum anti-O. radiatum IgG2 antibodies from vaccinated calves were used in immunoblots to identify the major immunogens. There were five major immunogens with molecular weights ranging from 70 to 150 kDa. Fractions separated by high-pressure liquid chromatography contained immunogens that were used to immunize calves. Vaccination with these fractions was found to impart the same level of protective immunity and induced similar IgG2 antibody and cellular immune responses as the crude whole worm extract even with 100-fold less protein.  相似文献   

7.
Stimulation of different T-cell subsets during antigen presentation influences the antibody isotype response to an antigen. Salmonella infection and Salmonella bacterin vaccination are likely to stimulate different T-cell subtypes. The objective of this study was to determine whether there are differences in the isotype response of cattle to Salmonella antigens following Salmonella infection and Salmonella bacterin vaccination. Sera from Salmonella bacterin-vaccinated, experimentally infected, and chronically infected (carrier) adult cattle collected during previous studies was used to evaluate the IgG1, IgG2, and IgM isotype responses of cows to Salmonella serotype Dublin lipopolysaccharide (LPS) and porin. Following vaccination and experimental oral infection, IgG1 titers to LPS and porin rose more quickly and persisted longer than did IgG2 titers. In contrast to Salmonella infection, bacterin vaccination stimulated a weak response to Salmonella porin. Salmonella infection also induced a higher IgG2:IgG1 titer ratio to LPS than did bacterin vaccination. Chronic Salmonella infection induced the highest LPS and porin IgG2:IgG1 titer ratios and the highest correlation between LPS and porin titers. Response operating characteristic curves for each isotype-specific enzyme-linked immunosorbent assay (ELISA) were determined to evaluate the effect of isotype on the sensitivity and specificity of Salmonella ELISA serology for distinguishing sera of Salmonella carriers from those of vaccinated and acutely infected cows. IgG2 titers to LPS and porin provide a more specific indicator of chronic Salmonella infection status than do IgG1 titers to the same antigens with little to no loss in sensitivity.  相似文献   

8.
Outer membrane protein isolated from Salmonella gallinarum was examined at different concentrations with or without a mineral-oil adjuvant for its immunogenicity and protection against live challenge. A formalin-killed whole-cell bacterin of the same organism was used for comparison. The results suggested that membrane proteins from S. gallinarum give better protection than formalin-killed whole-cell bacterin. Addition of an oil adjuvant to the protein appeared to increase the efficiency of the vaccine. When protein was given to chickens at 400 micrograms/100 g of live body weight, it produced 100% protection against oral challenge with S. gallinarum.  相似文献   

9.
The efficacy of two bacterins containing an Actinobacillus pleuropneumoniae serotype 10 strain was evaluated. The bacterial cells constituting bacterin 1 and 2 were grown under nicotinamide adenine dinucleotide (NAD)-rich (low-adherence capacity to alveolar epithelial cell cultures) and NAD-restricted (high-adherence capacity to alveolar epithelial cell cultures) conditions, respectively. Ten pigs were vaccinated twice with the bacterin 1 and nine pigs with the bacterin 2. Ten control animals were injected twice with a saline solution. Three weeks after the second vaccination, all pigs were endobronchially inoculated with 106.5 colony-forming units (CFU) of an A. pleuropneumoniae serotype 10 strain. In the bacterin 1 and 2 group, three and two pigs died after inoculation, respectively. Only two pigs of the control group survived challenge. Surviving pigs were killed at 7 days after challenge. The percentage of pigs with severe lung lesions (> 10% of the lung affected) was 100% in the control group, 70% in the bacterin 1 group and 22% in the bacterin 2 group. Actinobacillus pleuropneumoniae was isolated from the lungs of all animals. The mean bacterial titres of the caudal lung lobes were 7.0 x 10(6) CFU/g in the control group, 6.3 x 10(5) CFU/g in the bacterin 1 group and 1.3 x 10(6) CFU/g in the bacterin 2 group. It was concluded that both bacterins induced partial protection against severe challenge. Furthermore, there are indications that the bacterin 2, containing A. pleuropneumoniae bacteria grown under conditions resulting in high in vitro adhesin, induced better protection than the bacterin 1.  相似文献   

10.
Killed vaccines in oil emulsions are critical components of breeder and layer vaccination programs. Current vaccination sites are limited, and each has inherent problems. Oil emulsion vaccines are associated with increased condemnations of spent fowl when vaccines are injected intramuscularly into the breast. In an attempt to reduce tissue reaction when injected into the breast muscle, a commercially available Pasteurella multocida bacterin was heated to 41 C (100 F) for 5 hr prior to administration. A second treatment group was injected with the same bacterin at room temperature, 25 C. The vaccine was injected into the breast muscle at 10 and 18 wk of age into white Leghorn hens. Seroconversion was evaluated using P. multocida enzyme-linked immunosorbent assay (ELISA) at 10, 18, and 24 wk. Treatment and control groups were euthanized and lesions scored at 24 wk of age. One replicate was challenged with type 1 P. multocida at 24 wk of age. Lesion scores for the heated vaccine group were significantly lower than the room temperature vaccine. ELISA titers were not significantly different at 24 wk between the two treatment group; however, a significant rise in antibody titer was observed at 18 wk in the group that was injected with the heated vaccine. Survivability to challenge was improved in birds injected with the heated vaccine. Results suggest that heating of a P. multocida bacterin reduces local tissue reaction without having a deleterious effect on immunity as measured by ELISA and challenge.  相似文献   

11.
A lymphocyte transformation microassay was used to study cell mediated immunity (CMI) in chickens following primary and secondary vaccination with inactivated oil emulsion infectious bronchitis (IB) vaccine and subsequent challenge with Massachusetts-41 (M-41). Humoral immunity was monitored for comparison, using the haemagglutination inhibition (HI) microassay. Positive stimulation indices (2 to 2.7 after primary and 2 to 4.8 after secondary vaccination) were lower and HI titres were higher than those previously reported following primary and secondary vaccination with live IB vaccines. The highest HI titres appeared in birds which had received the inactivated vaccine as a secondary vaccination. Challenge of vaccinated and revaccinated birds resulted in strong HI and weak CMI secondary responses. There was no correlation between CMI and HI antibody production. Monitoring egg production and clinical signs showed that a high level of protection against challenge resulted from revaccination with an inactivated oil adjuvant vaccine.  相似文献   

12.
The effects of vaccination of Merino sheep with the purified pili or the whole cells of Bacteroides nodosus strain 198, either in oil or alum-oil adjuvant, on the severity of foot-rot induced with the homologous strain (198) and a heterologous strain (217) were determined in a field experiment, on flood irrigated pasture. The efficacy of the whole cell vaccines was comparable to that of purified pili vaccines, against homologous challenge, when both had a similar content of pilus antigen although the purified pili vaccines induced significantly greater homologous pilus agglutinating antibody titres than the whole cell vaccines. However, against heterologous challenge, the whole cell vaccines in oil (CO) or alum-oil (CAO) provided significantly greater protection than a purified pili-in-oil (PPO) vaccine, the number of severely affected feet in sheep vaccinated with PPO being similar to that of the unvaccinated group. The group vaccinated with purified pili in alum-oil (PPAO) was intermediate between these two extremes. The superior performance of the PPAO in comparison to the PPO vaccine, against heterologous challenge, was associated with significantly higher mean ELISA titres to the outer membrane complex. Western blot analyses implicated a role in cross-protection for outer membrane proteins, in particular a protein Mr 78,000. The PPO vaccine produced fewer, smaller and less persistent vaccination reactions at the inoculation sites than did the other vaccines. Bodyweight gains in the period prior to challenge were much lower for the groups vaccinated with CO and CAO than for the controls and those vaccinated with purified pili, due presumably to the larger vaccination reactions.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

13.
An enzyme-linked immunosorbent assay was used to determine the serum antibody response to Pasteurella haemolytica lipopolysaccharide (LPS) for calves vaccinated with saline solution, a formalin-killed P haemolytica bacterin, or live P haemolytica. Bacterin-vaccinated calves had a lower antibody response to LPS than did calves vaccinated with live P haemolytica. Calves vaccinated with either saline solution or the bacterin were more susceptible to intrapulmonic challenge exposure with P haemolytica than were calves vaccinated with liver organisms. Serum antibody responses to P haemolytica LPS did not seem important for resistance to challenge exposure, because there was no significant correlation (P greater than 0.05) between the lung lesion score and antibody response to P haemolytica LPS. There was a highly significant correlation (P less than 0.001) between antibody detected against P haemolytica LPS and that against formalin-killed P haemolytica. Competitive binding studies indicated that P haemolytica LPS is a major antigenic determinant on the surface of P haemolytica. There did not seem to be substantial cross-reaction between LPS from P haemolytica and that from Escherichia coli (serotype O26:B6).  相似文献   

14.
An indirect test based on horse blood was used to study bactericidal responses of the horse to Streptococcus equi following infection or vaccination. Bactericidal antibody appeared in convalescent sera between two and four weeks and high titres were usually attained by eight weeks. Infection without clinical evidence of abscessation was also effective in eliciting strong bactericidal responses. Serum bactericidal activity of horses either recovered from strangles or immunised with commercial bacterin had declined eight months after vaccination. However, horses that developed strangles eight to 10 months after vaccination exhibited rapid and substantial increases in serum bactericidal activity. Groups of yearlings immunised with commercial S equi vaccines consisting either of M protein or bacterin developed clinical strangles within six months of vaccination although the majority of the animals had exhibited strong serum bactericidal activity a few weeks before occurrence of the disease. Similarly, a group of seven yearling ponies hyperimmunised with experimental vaccine, rich in M protein, were found to be highly susceptible to an intranasal challenge of 5 X 10(8) colony forming units of S equi, although their sera exhibited strong bactericidal activity at the time of challenge. These observations suggest that the role of serum bactericidal antibody in protection of the horse against strangles has been overrated.  相似文献   

15.
In three experiments subcutaneous vaccination of calves with adjuvanted bacteria-free leukotoxic culture supernatant from log phase cultures of Pasteurella haemolytica A1 (toxin 1) was shown to induce some protection against intrabronchial challenge with live P. haemolytica A1. This toxin 1 vaccine was as effective as a whole cell bacterin in stimulating agglutinating antibody to P. haemolytica. Induction of leukotoxin neutralizing activity was variable; in some cases vaccination only primed the animal to produce an anamnestic response after challenge, whereas in other instances antitoxic activity increased in response to immunization. Two doses of vaccine were shown to be more effective than a single immunization. Vaccination with leukotoxic culture supernatant from the nonpathogenic P. haemolytica serotype 11 was as effective as vaccination with toxin 1 in stimulating antitoxic activity but was not protective. This implies that both serospecific agglutinating activity and an antitoxic response are needed for immunity.  相似文献   

16.
Calves maintained in insolated pens were vaccinated with an inactivated parainfluenza virus type (3) (pi3) vaccine usingparenteral and local route singly and in combination. The calves were subsequently monitored for serum antibody response and challenged intranasally with live virus to assess the protection derived from vaccination. Calves receiving one subcutaneous dose of vaccine in oil adjuvant produced a marked antibody response and were partially protected against challenge. Those receiving two successive subcutaneous doses produced a much greater antiboyd response and were completely protected against challenge. One intranasal dose of aqueous vaccine failed elicit a significant serum antibody response or protection against challenge. However, there was some evidence that intranasal vaccination following a single subcutaneous vaccination produced more effective immunity than one subcutaneous dose alone. Thus a vaccination regime was established which protected calves against experimental challenge and which could thefore be used in the field to assess the role of Pi3 virus in calf respiratory disease.  相似文献   

17.
The immunoglobulins (IgG1, IgG2, IgM, and IgA) of the Brucella-specific antibody response of 69 crossbred beef heifers were studied after Brucella abortus strain 19 vaccination and strain 2308 challenge exposure. The immunoglobulin isotype responses in serum and vaginal mucus were measured by use of fluorescent immunoassay. Serum antibody responses were detected also by 3 standard serologic tests (complement fixation [CF], Rivanol precipitation, and the CARD test] and 2 primary bindings assays that detect IgG antibodies. One month after vaccination, mean antibody titers for all immunoglobulin isotypes were higher for vaccinated cattle (n = 46) than for nonvaccinated controls (n = 23). After vaccination, IgA antibody responses in vaccinated cattle were only 2-fold higher than those for controls, whereas IgG1, IgG2, and IgM antibody responses were 3- to 90-fold greater than those for controls. Measurement of IgA antibody responses classified 21 of 39 vaccinates as seropositive after vaccination, whereas the other isotypes classified 28 or 34 cattle as seropositive. Three months after challenge exposure, the mean antibody responses for each isotype were higher in cattle that aborted or were culture positive than in cattle that did not abort and were culture negative. Although IgG1, IgG2, and IgM antibody titers were each of benefit in identifying B abortus-infected cattle, it did not appear that the magnitude of the antibody responses provided sufficient discrimination between S19-vaccinated cattle and S2308 challenge-exposed cattle. Serum IgA antibody responses were 10-fold higher after challenge exposure than after vaccination and may be a response to mucosal infection with the virulent organism.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

18.
Streptococcus suis diseases in pigs, most importantly meningitis, are worldwide responsible for major economic losses in the pig industry. About one fourth of invasive S. suis diseases are caused by S. suis serotype 9 strains in Europe. However, little is known about serotype 9 since most studies were performed with serotype 2. The objective of this study was to determine the immunogenicity and protective efficacy of a serotype 9 bacterin in piglets. Challenge was conducted with a reference serotype 9 strain, belonging to the same clonal complex but to a different sequence type as the bacterin strain. The bacterin induced protection against mortality but not morbidity. Eleven days post infection, 3 of 7 vaccinated survivors were not fully convalescent and had not eliminated the challenge strain from inner organs completely. In accordance with the clinical findings, the majority of piglets showed fibrinous-suppurative lesions in at least one inner organ or tissue. In contrast to the placebo group such lesions were not detected in one third of bacterin-vaccinated piglets. Determination of specific serum IgG titers revealed that the bacterin elicited seroconversion against muramidase-released protein and basic membrane lipoprotein. Furthermore, vaccination was associated with induction of opsonizing antibodies against the serotype 9 challenge strain. However, titers of opsonizing antibodies were rather low in comparison to those found in our previous serotype 2 vaccination trial. Piglets developed substantially higher titers of opsonizing antibodies after challenge. Opsonizing antibodies were absorbable with the serotype 9 challenge strain but not with an unencapsulated isogenic mutant of a serotype 2 strain indicating their specificity. The results indicate that a serotype 9 bacterin is less protective than a serotype 2 bacterin, most likely due to inducing only low titers of opsonizing antibodies. This might contribute to emergence of serotype 9 strains, in particular strains of this clonal complex, in Europe.  相似文献   

19.
OBJECTIVE: To determine efficacy of intranasal vaccination of rabbits with Pasteurella multocida A:3 outer membrane proteins (OMP) expressing iron-regulated OMP (IROMP) in conferring protection against experimental challenge exposure. ANIMALS: 52 male New Zealand White rabbits. PROCEDURE: Rabbits were vaccinated intranasally on days 0, 7, and 14; some vaccines included cholera toxin (CT) as an adjuvant. Concentrations of intranasal IgA and serum IgG antibodies against P multocida OMP were determined. In experiment A, rabbits were vaccinated with either phospate-buffered saline solution (PBSS), PBSS-CT, OMP-CT, or IROMP-CT, challenge-exposed intranasally on day 16, and euthanatized and necropsied on day 28. Rabbits were also vaccinated with OMP or IROMP without CT and were not challenge-exposed. In experiment B, rabbits were vaccinated with PBSS, PBSS-CT, IROMP, or IROMP-CT. On day 17, rabbits were challenge-exposed intranasally. Nasal bacteria and antibodies were determined on day 24. RESULTS: In experiment A, OMP-CT vaccination stimulated mucosal and systemic antibody responses to the bacterium and enhanced resistance against challenge exposure. Intranasal bacterial counts were not significantly reduced. Vaccination with IROMP-CT stimulated mucosal and systemic antibodies, enhanced resistance to challenge exposure, and significantly reduced nasal bacterial counts. In experiment B, natural infection was detected in several rabbits at challenge exposure; however, IROMP-CT-vaccinated rabbits had significantly higher serum and nasal antibody responses, compared with other rabbits IROMP-CT-vaccinated rabbits had significantly lower nasal bacterial counts compared to control rabbits. CONCLUSIONS AND CLINICAL RELEVANCE: Intranasal vaccination of rabbits with P multocida outer membranes containing IROMP and CT stimulated immunity against experimental pneumonic pasteurellosis.  相似文献   

20.
Vaccination-challenge experiments were carried out with dairy heifers using new, killed cell-toxoid-adjuvant Staphylococcus aureus vaccines. The organisms in the vaccines were cultured under conditions which simulated in vivo growth and induced expression of a pseudocapsule. Dextran sulphate which promotes synthesis of IgG2 antibody was included in the vaccines as the primary adjuvant. Vaccinated heifers developed very high levels of both IgG1 and IgG2 anti-pseudocapsule antibody in serum, however, titres of neutralising antibody against toxoided haemolysins were generally low. Vaccinated and unvaccinated control heifers were challenged by intramammary infusion of three virulent strains of S aureus in four experiments. Vaccinated heifers were more resistant to clinical mastitis following challenge than were controls, and the vaccinates had significantly greater milk production than controls following challenge. The most promising vaccine had dextran sulphate combined with mineral oil as the adjuvant injected intramuscularly.  相似文献   

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