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1.
Eighty-eight cattle were injected SC with 2.5 x 10(8) viable cells of Brucella abortus strain 19. All but 1 heifer became seropositive on the basis of the results of 7 brucellosis tests, and the proportion positive decreased with time. The proportion of cattle that were seropositive during a 20- to 67-week period after vaccination was as follows, in decreasing order: hemolysis-in-gel, 59%; buffered-acid plate antigen, 39%; ELISA, 16%; card, 10%; rivanol, 8%; cold complement-fixation, 7%; and automated complement-fixation, 5%. Using the serologic classification in Uniform Methods and Rules for brucellosis eradication, 7 cattle tested brucellosis-positive (2 suspects and 5 reactors). None of the 27 nonpregnant heifers tested positive. Of 18 heifers that were 84 to 135 days in gestation when vaccinated, 6 (33%) tested positive for brucellosis, compared with 0 of 13 and 1 (3%) of 30 heifers that were 11 to 78 and 145 to 253 days in gestation at vaccination, respectively (X2 = 12.07; 2 df; P less than 0.01). Neither breed (Angus, Hereford, Jersey, and Brahman) nor calf survival was related to brucellosis-positive results. Postpartum milk samples from 61 heifers and 24 tissues from 2 reactor cattle were culture-negative for B abortus.  相似文献   

2.
A trial was conducted in two villages (one containing cattle infected with brucellosis and one not containing infected cattle) in Timor, Indonesia to determine the serological response to vaccination with Brucella abortus strain 19 in Bali cattle (Bos javanicus) (n = 599). Mature female cattle were immunised with low-dose strain 19 (2x10(8)-6x10(8) colony forming units) and calves (6-12 months) with high-dose strain 19 (4x10(10)-12x10(10) colony forming units). Other mature females and calves were inoculated with sterile vaccine diluent and formed a non-vaccinated in-contact control group. The seroprevalence and mean titres were highest in the vaccinated cattle 3 months after vaccination. These then receded, however, 1% of vaccinated calves and 1.9% of vaccinated cows from the village without infected cattle were still seropositive on the complement-fixation test (CFT) 24 months after vaccination. Non-vaccinated seropositive animals were more likely to have aborted or had a stillbirth and were less likely to have produced a calf than were seronegative cows from the village containing infected animals. We concluded that strain 19 vaccine induced protection in Bali cattle and that this vaccine might play an important role in the control of bovine brucellosis in Timor.  相似文献   

3.
Heifers injected with 10(8) (n = 40), 10(9) (n = 39), or 10(10) (n = 39) colony-forming units of Brucella abortus strain 19 were conjunctivally exposed to 10(7) colony-forming units of strain 2308 during gestation. At parturition, milk from each quarter of the udder, a piece of placenta, and 2 swab specimens of the uterus from the dam plus a swab specimen of the rectum from each calf were cultured for Brucella. If the calf was dead or died, additional specimens of lung, stomach contents, and a mediastinal lymph node also were cultured. Days in gestation was determined for each heifer, using data from rectal palpation after breeding and crown-rump length and weight of calf at parturition, with the median value used for data analysis. In each vaccine dosage group, the proportion (%) of heifers developing brucellosis increased as days in gestation at exposure increased. Strain 2308 was isolated from 3 (11%) of 26, 16 (25%) of 64, and 18 (64%) of 28 heifers that were grouped as less than 121, 121 to 150, and greater than 150 days in gestation at time of exposure, respectively. Thirty-two (86%) of the 37 infected heifers were less than 260 days in gestation at parturition, and calves were premature. Heifers with premature calves were more likely to be infected, and tissues were more likely to yield multiple isolations of strain 2308, regardless of days in gestation at exposure or of days after exposure to parturition. Days after exposure to premature parturition of infected heifers ranged from 35 to 110.  相似文献   

4.
A total of 250 adult cows and 13 (young) heifers, all seronegative for brucellosis, were vaccinated with a reduced dose (3 × 109) Strain 19 (S‐19) vaccine. Twelve months after vaccination all cattle were negative to the serological tests. The results obtained are similar to those found by other authors and support the use of reduced dose S19 under the heat conditions found in Zambia.  相似文献   

5.
In the studies reported here, protection induced by calfhood vaccination of bison with 1.2-6.1 x 10(10)CFU of Brucella abortus strain RB51 (SRB51) against a virulent strain of B. abortus was evaluated. Non-vaccinated and SRB51-vaccinated bison were intraconjunctivally challenged during midgestation with 3 x 10(7)CFU of virulent B. abortus strain 2308 (S2308). Maternal and fetal tissues were obtained within 24hour after abortion or parturition. Incidence of abortion was greater (P<0.05) in non-vaccinated as compared to SRB51-vaccinated bison (62% and 15%, respectively), with abortions occurring between 5 and 8 weeks after experimental challenge. Calves from bison vaccinated with SRB51 had a reduced (P<0.05) prevalence of fetal infection with S2308 as compared to calves from non-vaccinated bison (19% and 62%, respectively). Although the ability to recover the 2308 challenge strain from maternal tissues did not differ (P>0.05) between nonvaccinates and vaccinates (100% and 78%, respectively), calfhood vaccination with SRB51 reduced (P<0.05) recovery of S2308 from uterine or mammary gland tissues. In bison which did not abort, S2308 was routinely recovered in low numbers from maternal lymphatic tissues; particularly the parotid, bronchial, supramammary, and mandibular lymph nodes. The RB51 vaccine strain was not recovered at any time from maternal or fetal samples obtained at necropsy. Histological lesions associated with Brucella-induced abortions were suppurative placentitis, fetal broncho-interstitial pneumonia, and fetal histiocytic splenitis. The results of our studies suggest that calfhood vaccination of bison with SRB51 is efficacious in protecting against intramammary, intrauterine, and fetal infection following exposure to a virulent strain of B. abortus during pregnancy. As brucellosis is transmitted horizontally through fluids associated with the birth or abortion of an infected fetus, or vertically to the calf through the ingestion of milk containing B. abortus, our data suggest that calfhood vaccination with SRB51 will be beneficial in preventing transmission of brucellosis in bison.  相似文献   

6.
Augmentation of immunization of cattle Brucella abortus S19 or a B. abortus soluble protein extract (SPEBA) vaccine through administration of recombinant bovine IL 2 (rBoIL 2) was evaluated. Seventy-five heifers were divided among 6 groups that were treated with the following: Group 1, no treatment; Group 2, rBoIL 2 (1microg/kg) on day 0; Group 3, SPEBA (2 mg) on day 0 and week 9; Group 4, SPEBA + rBoIL 2 on day 0, SPEBA on week 9; Group 5, S19 (10(7) CFU) on day 0 and week 9; Group 6, S19 + rBoIL 2 on day 0, S19 only on week 9. Approximately, 6 months after vaccination, cattle were bred by natural service, and at mid-gestation pregnant cattle were challenged intraconjunctivally with 9.1 x 10(5) CFU of virulent B. abortus S2308. Pre- and post-challenge antibody responses were measured by an enzyme-linked immunosorbent assay, a particle concentration fluorescence assay, and the card test. Lymphoproliferation (LP) responses to gamma-irradiated B. abortus and SPEBA antigens were measured in peripheral blood mononuclear cells. After vaccination, antibody responses to B. abortus elevated rapidly in SPEBA- and S19-vaccinates with and without rBoIL 2, however, these responses were significantly (P < 0.05) higher in vaccinates which also received rBoIL 2. Antibody levels for all vaccinated groups had returned to those of negative control groups by the challenge date with the exception of the SPEBA/rBoIL 2 group. In general, LP responses were higher in vaccinated or rBoIL 2-treated cattle than for unvaccinated controls. Challenge of 48 pregnant heifers resulted in abortions in 4/9 of Group 1, 0/9 of Group 2, 4/8 of Group 3, 2/9 of Group 4, 1/7 of Group 5, and 0/6 of Group 6 cattle. Treatment with rBoIL 2 alone (Group 2) provided significant (P < 0.05) protection from infection, abortions and induction of sero-positive status compared to untreated (Group 1) cattle. Co-administration of rBoIL 2 with S19 resulted in significant (P < 0.05) augmentation in onset, duration and magnitude of LP responses to B. abortus antigens following challenge. Characterization of the cytokine response of bovine monocyte-derived macrophages by real-time polymerase chain reaction indicated that in vitro stimulation of these cells with rBoIL 2 resulted in a profound up-regulation of genes encoding tumor necrosis factor-alpha, IL 12p40, and interferon-gamma reflecting activation of the cells. Overall, rBoIL 2-treatment was associated with fewer infections, sero-conversions and a significant (P = 0.02) level of protection against abortion as compared to vaccination alone or no treatment.  相似文献   

7.
To assess the ability of the differential complement fixation test to distinguish vaccinal reactors from infected cattle, approximately 1,000 heifers were tested by the complement fixation test (CFT) using rough and smooth brucella antigens, before the injection of 45/20 vaccine and at 3 and 6 or 10 weeks after vaccination. Before vaccination 91.5% of heifers were negative to the rough antigen but 0.6% were positive with high titre (greater than or equal to 128). By 10 weeks after injection of 45/20 vaccine 97.6% of heifers were positive to the rough CF antigen, at greater than or equal to 8, a majority reaching greater than or equal to 128. Nineteen pre-vaccinal reactors to the standard CFT were killed and Brucella abortus was isolated from the tissues of 14. Twenty-six post-vaccinal reactors were killed and B. abortus was isolated from the tissues of 8. In the 22 B. abortus infected animals the differential CFT classified 9 correctly as infected, 5 incorrectly as vaccination reactions and 8 as inconclusive. The differential CF was ineffective in distinguishing titres resulting from vaccination with 45/20 vaccine from those due to infection.  相似文献   

8.
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   

9.
Seventy-nine cattle in all stages of gestation were inoculated with a low dose (2.5 x 10(8) colony-forming units) of Brucella abortus strain 19, then challenge exposed with pathogenic B abortus strain 2308 during the subsequent gestation. A brucellosis case was defined by isolation of strain 2308 from dam or calf samples. Cumulative incidence of brucellosis cases was 48, 33, 25, or 47% for cattle that were, respectively, not pregnant, or 19 to 87, 100 to 167, or 190 to 253 days in gestation at vaccination. The cumulative incidence was 56% in 27 nonvaccinated controls. The 95% confidence intervals for risk ratios included 1 in all cattle, except those that were 100 to 167 days in gestation at vaccination (ie, second trimester); the confidence interval for this group was 0.21 to 0.97. The prevented fraction (1-risk ratio) attributed to strain 19, in ascending order, was 0.14, 0.16, 0.4, or 0.55, respectively, for cattle that were not pregnant, or were 190 to 253, 19 to 87, or 100 to 167 days in gestation at vaccination. Potential confounders of breed, pen effect, and gestation days at challenge exposure did not significantly affect results. Results supported the hypothesis that stage of gestation at vaccination will affect the prevented fraction of brucellosis, or efficacy of strain 19, in cattle vaccinated with a low dose and, therefore, is one factor that may explain variation in strain 19-induced protection.  相似文献   

10.
SUMMARY Three groups, each of 14 mature Jersey heifers, were vaccinated. They were mated about 2 months later and those that became pregnant were challenged at about 6.5 months of pregnancy by the conjunctival application of virulent Brucella abortus. Group 1 heifers received 2 doses of B. abortus 45/20 vaccine 2 months apart. Only 5 of the 14 heifers became pregnant, and of these 5 only one resisted challenge. Group 2 heifers received only one dose of 45/20 vaccine, 5 of the 10 challenged resisted infection. Group 3 heifers received 3 × 108 cfu of strain 19. Six of the 10 heifers challenged resisted infection. All of 5 non-vaccinated control cattle became infected. It appeared advantageous to give only one dose of 45/20 rather than 2 as presently recommended. A single dose of 45/20 vaccine induced resistance to virulent B. abortus approximately equal to that given by the reduced dose of strain 19. One dose of 45/20 vaccine stimulated transient serological positivity in 2 of 28 heifers whereas the reduced dose of strain 19 gave rise to persistent titres in 2 of 14 vaccinated heifers.  相似文献   

11.
Three hundred sixty cattle at risk in 6 beef herds known to include cows infected with Brucella abortus field strains were vaccinated with 3 x 10(9) colony-forming units of strain 19. Field strain exposure after vaccination was estimated by the number of cows with brucellosis that calved or aborted in the herd. As the number of exposures increased, the number of cows developing brucellosis increased, and 19 exposures in the 6 herds resulted in 9 new cases. The ratio of exposures to new cases varied from 1.0 to 2.0 in the 4 herds with new cases, whereas 2 herds with 1 and 3 exposures, respectively, did not have new cases of brucellosis. The correlation coefficient between the number of exposures and the number of new cases was 0.85, and the coefficient of determination suggested that 73% of the variation in new cases could be explained by the number of exposures in strain 19-vaccinated herds.  相似文献   

12.
Fifty-six heifers were weaned from dams that were card-test positive for brucellosis. Forty-four dams were positive by rivanol and complement-fixation tests and Brucella abortus field strain was isolated from 14. Numbers of expected pregnancies following natural breeding and numbers of viable calves produced were not reduced in the heifers. Persistent B abortus infection was documented in 2 of 37 parturient heifers from reactor dams. The frequency of infection was 1 of 10 in strain 19-vaccinated heifers, and 1 of 27 in nonvaccinated heifers. The 2 persistently infected heifers had atypical serologic reaction patterns before normal parturitions.  相似文献   

13.
Milk culture data and serologic test results were evaluated after adult vaccination with Brucella abortus strain 19 in cattle of 3 large California dairy herds infected with brucellosis. Strain-19 organisms were isolated by culture of milk from 1.9% of the vaccinated cows. Isolation of field strain of B abortus varied directly with magnitude of complement-fixation (CF) and rivanol titers. At time of milk culture, 74% of cows from which field strain was isolated had CF titer greater than or equal to 160, compared with 58% of cows from which strain 19 was isolated. Cows with CF titer greater than or equal to 160 at 2 months or greater than or equal to 80 to 4 months after adult vaccination were more likely to be correctly classified as reactors (on the basis of subsequent milk culture results and/or persistently high serologic titer) than were cows with lower CF titer at these times. Cows from which B abortus strain 19 was isolated from milk were more likely to maintain persistent serologic titer than were cows from which neither strain of B abortus was isolated.  相似文献   

14.
Twenty heifers were vaccinated orally with Brucella abortus strain 19. These heifers and 21 control heifers were challenge exposed in midgestation with strain 2308 by the oral route. Ten of 19 pregnant control heifers aborted and 14 were culture positive. Two additional heifers were seropositive at slaughter. Strain 2308 was recovered from 4 vaccinates at slaughter; none of the vaccinates aborted. Titers after oral vaccination persisted for less than 82 days.  相似文献   

15.
[目的]为了检验S19号疫苗的预防效果。[方法]用S19号疫苗对未孕母牛进行接种,然后用琥红平板凝集试验监测。[结果]不同个体免后4～5个月的转阳率55.8%,免后6～8个月的转阳率63.5%,免后11～12个月的转阳率57.5%,同一养殖区内注苗后的转阳率平均57.7%,未注苗的自然感染率达到16.2。[结论]说明疫...  相似文献   

16.
布鲁氏菌弱毒疫苗粘膜免疫及检测方法的研究   总被引：1，自引：0，他引：1  
为研究布鲁氏菌弱毒疫苗粘膜免疫及其检测方法,本实验采用粘膜点眼途径对健康母羊接种布鲁氏杆菌猪2号疫苗(S2)、牛19号疫苗(A19)和羊强毒株(M16),筛选布鲁氏杆菌病鉴别检测方法。将12月龄～14月龄母羊60只随机分为3组,以常规疫苗推荐剂量进行半量粘膜点眼接种。采集血液、淋巴、脏器进行布鲁氏菌病血清学检测和细菌学分离以及PCR检测。结果表明:布鲁氏菌弱毒疫苗抗体水平持续6个月,其中血清学的试管凝集试验、半胱氨酸凝集试验与补体结合试验的阳性符合率达到100%。细菌分离期为6个月,乳腺、乳腺淋巴、髂淋巴分离率较高;而强毒株M16的抗体水平和细菌分离持续12个月以上。结果显示以常规血清学和细菌学检测方法在点眼免疫布鲁氏菌S2、A19苗6个月后可以进行野毒感染和疫苗免疫畜的鉴别诊断。  相似文献   

17.
Fifty-seven pregnant beef heifers that were unvaccinated or previously vaccinated with Brucella abortus S19, at a dose of either 109 or 1010 colony-forming units (CFU), were challenge-exposed intraconjunctivally with virulent B. abortus S2308 at a dose of 9.4 × 106 CFU (Experiment 1) or 5.2 × 107 CFU (Experiment 2). In Experiment 1, S19 afforded significant protection (P < 0.01) against challenge exposure in that 8 of 9 unvaccinated heifers, 1 of 11 vaccinated with 109 CFU, and 3 of 10 vaccinated with 1010 CFU aborted or delivered weak, non-viable calves. In Experiment 2, vaccination did not afford significant protection (P> 0.05) in that 9 of 9 unvaccinated heifers, 8 of 10 vaccinated with 109 CFU, and 8 of 8 vaccinated with 1010 CFU aborted. Serologic responses to B. abortus were determined by three standard tests, as well as a quantitative fluorometric immunoassay (FIAX) and an enzyme-linked immunosorbent assay. In Experiment 1, the early serologic response, 0–8 weeks after challenge, appeared greater for controls than for vaccinates, but in Experiment 2, the early response, 0–6 weeks after challenge exposure, appeared greater for vaccinates than for controls. The lymphocyte blast transformation assay, using heat-killed B. abortus as an antigen, was performed sequentially after challenge exposure. In general, mean responses were significantly higher (P < 0.05) for vaccinated than for non-vaccinated heifers. For individual heifers, an association could not be established between the lymphocyte blast transformation assay and the clinical response to challenge exposure.  相似文献   

18.
Cell-mediated immunity to Brucella abortus S19 vaccine was measured in young heifers by the microassay for stimulation of protein synthesis (SPS) with [3H]leucine and the skin test for delayed hypersensitivity. Brucella melitensis protein allergen and a crude B abortus S19-soluble antigen were compared in the SPS test. The SPS test was negative in 5 unvaccinated heifers and strongly positive in 3 twice-vaccinated steers. However, the SPS test was positive only in 13 of 30 S19-vaccinated heifers and the delayed hypersensitivity in 9 of 29 S19-vaccinated heifers. The 2 tests gave good agreement. Vaccination-induced residual antibody titers were partly correlated with the outcome of the tests used to measure cell-mediated immunity.  相似文献   

19.
通过构建标记疫苗株来解决流产布氏杆菌(B.abortus)鉴别诊断方面的缺陷,本研究以bp26基因作为重组靶住点,S19为亲本,利用bp26基因ORF外侧序列作为同源重组序列,卡那霉素抗性基因(Kanr)为抗性筛选标记,通过双交叉重组筛选获得bp26基因缺失突变的重组S19株,命名为S19-△26.小鼠感染结果表明,突变株S19-△26的残留毒力与亲本株S19相比较没有发生明显改变,康复时间约为15周,突变株S19-△26、亲本株S19和B.abortus强毒株S544接种小鼠后的第3周能检测出"O"抗原的特异性抗体,而第6周开始S19和S544接种小鼠BP26特异性抗体明显升高,S19-△26接种的小鼠一直没检测到BP26特异性抗体.小鼠免疫保护试验显示,脾脏分离CFU数比空白对照要低310g10,S544攻击后脾脏细菌分离数表明突变株具有与亲本疫苗株免疫保护性无明显差异.结果表明,S19-△26免疫能够通过血清学方法与野生型B.abortus感染后的免疫反应相区别,具备作为标记疫苗的潜力.  相似文献   

20.
Effectiveness of 2 concentrations of a monovalent vaccine containing Leptospira interrogans serovar hardjo type hardjo-bovis was evaluated for protection of heifers from infection with type hardjo-bovis. Nine heifers were given 2 doses of low-dose vaccine (8.32 x 10(8) cells/dose); 9 heifers were given 2 doses of high-dose vaccine (8.32 x 10(9) cells/dose); and 1 steer and 1 heifer were maintained as nonvaccinated controls. Groups of vaccinated cattle were challenge-exposed with serovar hardjo type hardjo-bovis at 7 (n = 6), 11 (n = 6), or 15 (n = 6) weeks after completion of vaccination. All cattle were challenge-exposed by conjunctival instillation of 1 x 10(5) hardjo-bovis cells on 3 consecutive days. Both control and all vaccinated cattle became infected and shed serovar hardjo type hardjo-bovis in their urine. Leptospires were detected in 15 of 16 (94%) urine samples from control cattle and in 124 of 143 (87%) samples from vaccinated cattle. Leptospires were detected in kidneys of 17 of 18 vaccinated cattle and 2 of 2 control cattle and in the uterus or oviducts of 13 of 18 vaccinates and the 1 control heifer.  相似文献   

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