Canine parainfluenza-Bordetella bronchiseptica vaccine immunogenicity

The immunogenicity and safety of 3 serials of a canine parainfluenza (CPI) virus-Bordetella bronchiseptica vaccine was evaluated. Each serial was used to vaccinate 10 dogs with single doses given intranasally. The 30 vaccinated and 10 nonvaccinated controls dogs were challenge exposed with aerosols of virulent CPI virus and B bronchiseptica at 18 days and at 21 days, respectively, after vaccination. After challenge exposure, none of the 30 vaccinated dogs had clinical signs of disease; however, 9 of the 10 nonvaccinated dogs developed coughing problems. The CPI virus was isolated from nasal swab specimens obtained from nonvaccinated dogs on an average of 5.1 days after challenge exposure, but was not isolated from any of the specimens obtained from the vaccinated dogs. Bordetella bronchiseptica was isolated from nasal swab specimens obtained from both vaccinated and nonvaccinated dogs up to 18 days after challenge exposure. The erythrocyte sedimentation rates and total leukocyte counts for control dogs were generally increased, in contrast to those for the vaccinated groups. Dogs showed a primary serologic response to CPI virus and B bronchiseptica after vaccination and an anamnestic response to the bacterium after challenge exposure. Adverse local or systemic reactions attributable to the bivalent vaccine were not observed in the vaccinated dogs.     

Immunogenicity and safety of an attenuated Bordetella bronchiseptica vaccine in pigs

The immunogenicity and safety of an attenuated Bordetella bronchiseptica vaccine for swine atrophic rhinitis (AR) was evaluated in 22 hysterectomy-produced, colostrum-deprived pigs and 18 conventional pigs. None of 8 pigs inoculated at 7 days of age intranasally with greater than or equal to 3 X 10(5) colony-forming units (CFU) of vaccinal strain/pig and 2 of 5 pigs inoculated at 7 days of age intranasally with 3 X 10(4) CFU of the vaccinal strain/pig developed AR after intranasal challenge exposure with a virulent strain at postinoculation week (PIW) 3. The remaining 3 vaccinated pigs and 4 nonvaccinated pigs developed AR. Thirteen pigs were inoculated intranasally with 3 X 10(6) to 3 X 10(9) CFU of the vaccinal strain at 7 days of age. At PIW 12, the pigs were killed and necropsied. None of the pigs had clinical signs of AR and/or pneumonia. Virulence was studied by transmission of vaccinal strain through 3 serial growing passages on the nasal mucosa of a litter of hysterectomy-produced colostrum-deprived pigs. Inoculum (nasal swab samples from 2 pigs 4 days after inoculation with 10(8) CFU of vaccinal strain at 5 days of age) was inoculated into the nasal cavity of 2 nonvaccinated pigs. This procedure was repeated 3 times. After the 1st passage, the vaccinal strain was recovered on postinoculation day 4, but after postinoculation day 4, the vaccinal strain was not recovered until the end of the 3rd passage. Turbinate atrophy or pneumonia was not recognized in these inoculated pigs. The vaccinal strain provided immunogenicity without ill effects.     

Immunogenic and protective antigens of Brucella as vaccine candidates

Brucella is an intracellular pathogen that causes abortion in domestic animals and undulant fever in humans. Due to the lack of a human vaccine against brucellosis, animal vaccines play an important role in the management of animal and human brucellosis for decades. Strain 19, RB51 and Rev1 are the approved Brucella spp. vaccine strains that are most commonly used to protect livestock against infection and abortion. However, due to some disadvantages of these vaccines, numerous studies have been conducted for the development of effective vaccines that could also be used in other susceptible animals. In this review, we compare different aspects of immunogenic antigens that have been a candidate for the brucellosis vaccine.     

Efficacy of strain RB51 vaccine in protecting infection and vertical transmission against Brucella abortus in Sprague-Dawley rats

Immunizing animals in the wild against Brucella (B.) abortus is essential to control bovine brucellosis because cattle can get the disease through close contact with infected wildlife. The aim of this experiment was to evaluate the effectiveness of the B. abortus strain RB51 vaccine in protecting infection as well as vertical transmission in Sprague-Dawley (SD) rats against B. abortus biotype 1. Virgin female SD rats (n = 48) two months of age were divided into two groups: one group (n = 24) received RB51 vaccine intraperitoneally with 3 × 10¹⁰ colony forming units (CFU) and the other group (n = 24) was used as non-vaccinated control. Non-vaccinated and RB51-vaccinated rats were challenged with 1.5 × 10⁹ CFU of virulent B. abortus biotype 1 six weeks after vaccination. Three weeks after challenge, all rats were bred. Verification of RB51-vaccine induced protection in SD rats was determined by bacteriological, serological and molecular screening of maternal and fetal tissues at necropsy. The RB51 vaccine elicited 81.25% protection in SD rats against infection with B. abortus biotype 1. Offspring from rats vaccinated with RB51 had a decreased (p < 0.05) prevalence of vertical transmission of B. abortus biotype 1 compared to the offspring from non-vaccinated rats (20.23% and 87.50%, respectively). This is the first report of RB51 vaccination efficacy against the vertical transmission of B. abortus in the SD rat model.     

布鲁氏菌pcDNA3．1-omp17．3基因疫苗的研制

采用PCR方法扩增了布鲁氏菌17．3ku外膜蛋白编码基因，并将该基因克隆至真核表达载体pcDNA3．1（＋）中，成功构建了真核表达质粒pcDNA3．1-ompl7．3。pcDNA3．1-omp17．3转染coS-7细胞后，通过Western—blotting检测到了17．3ku蛋白的瞬时表达。将pcDNA3．1-ompl7．3免疫小鼠，三免后经ELISA、流式细胞仪以及ELISPOT技术检测到pcDNA3．1-omp17．3在小鼠体内诱导产生了以Th1型为主的细胞免疫应答。结果表明，构建的基因疫苗可作为潜在的布鲁氏菌新型疫苗，有进一步研究的意义。     

马耳它布氏杆菌bp26基因缺失株的构建及鉴定

为了建立马耳他布氏杆菌M5-90株弱毒疫苗株与野生株的鉴别诊断,本研究以bp26基因作为重组靶位点,以M5-90为亲本,利用bp26基因ORF外侧序列作为同源序列,将卡那霉素抗性基因(Kan')整合到细菌基因组中,双交叉重组阳性菌株,经SDS-PAGE和western blot试验表明迁移率约为29 ku的BP26蛋白在亲本菌中表达并可被鼠抗BP26高免血清识别,而突变株M5-90-26反应结果为阴性,表明BP26蛋白在突变疫苗株M5-90-26中未表达.M5-90-26具备从血清学角度区分M5-90-26免疫与野生型布氏杆菌感染,对布氏杆菌病防制、监测及净化具有重要的意义.     

Effect of aflatoxin B1 on resistance induced by Bordetella bronchiseptica vaccine in rabbits

The effects of aflatoxin B1 on the development of the immune response to oil-adjuvanted Bordetella bronchiseptica vaccine and on acquired resistance to bacterial challenge were studied in rabbits. The doses of aflatoxin used were insufficient to produce clinical intoxication. Rabbits were randomly assigned to three groups, each having six animals: control (T), vaccinated (V), and vaccinated plus aflatoxin (VA) at 0.05 mg/kg daily per os. Groups V and VA were vaccinated twice, and the three groups were subsequently challenged with virulent B. bronchiseptica. The average weight gain at weekly intervals was significantly reduced in group VA, and no statistically significant differences were found in the titers of agglutinating antibodies between groups V and VA. There were significant differences between groups V and VA in the extent and severity of the pneumonic process, group VA being most affected. Results indicated that agglutinating antibody titers were not related to the level of protection in the latter group. Other mechanisms, such as alveolar macrophage activity and cell-mediated immunity, were implicated in the impairment of the acquired resistance in rabbits subclinically intoxicated with aflatoxin.     

Protection of dogs for 13 months against Bordetella bronchiseptica and canine parainfluenza virus with a modified live vaccine

Twelve specific pathogen-free (spf) puppies were vaccinated intranasally with a bivalent, modified live vaccine against infectious tracheobronchitis (group 1) and six puppies of the same age and from the same source served as unvaccinated controls (group 2). Both groups were challenged with wild-type Bordetella bronchiseptica and canine parainfluenza virus by the aerosol route 56 weeks after group 1 had been vaccinated, and at the same time six 10-week-old spf puppies from the same source (group 3) were also challenged. Oronasal swabs were taken regularly before and after the challenge, for the isolation of bacteria and viruses, and the dogs were observed for clinical signs for three weeks after the challenge. The control dogs became culture-positive for B bronchiseptica and canine parainfluenza virus, but the isolation yields from the vaccinated group were significantly lower (P<0.05). The mean clinical scores of the vaccinated group were 61 per cent lower than the scores of group 2 (P=0.009), and 90 per cent lower than the scores of group 3 (P=0.001).     

布氏杆菌S2疫苗免疫绵羊血清抗体消长规律研究

为了解绵羊对布氏杆菌病S2疫苗免疫后的抗体消长规律,通过口服和注射2种方法对绵羊进行了布氏杆菌病S2疫苗免疫试验,利用虎红平板凝集试验(RBT)和试管凝集试验(SAT)以及c ELISA检测方法进行了血清抗体检测。结果表明:正常剂量口服免疫S2疫苗20 d后,RBT、SAT、c ELISA抗体阳性率均达到最高,分别是80%、70%、60%,并且在免疫100 d后羊血清抗体阳性率分别为RBT 20%、SAT 10%、c ELISA 10%,免疫250 d后3种方法检测结果均转为阴性。2倍剂量口服免疫S2疫苗20 d后,RBT、SAT、c ELISA均达到最高为60%,并在免疫100 d后均转为阴性。以正常剂量注射免疫S2疫苗免疫7 d后RBT和SAT抗体阳性率达到最高为80%,c ELISA抗体阳性率达到60%,30 d后达到80%,而疫苗免疫370 d后,RBT和SAT检测抗体阳性率下降到60%,c ELISA检测抗体阳性率依然80%;而2倍剂量注射免疫S2疫苗370 d后,RBT和c ELISA检测抗体阳性率仍保持着100%,SAT检测抗体阳性率达80%。结果表明,从免疫羊抗体产生及体内消长规律来看,布氏杆菌S2疫苗注射免疫明显优于口服免疫效果,且两种免疫途径的试验羊均且未发现明显接种副反应。     

粗糙型布鲁菌M111菌壳的制备

将含有裂解酶基因重组温控裂解质粒pBBR1MCS：：PR-PL-E电转化至粗糙型布鲁菌M111中,构建重组布鲁菌M111（pBBRlMCS：：PR-PL-E）。重组菌株在28℃培养,42℃诱导表达裂解酶E,从而制备布鲁菌菌壳。绘制布鲁菌生长曲线及裂解曲线,计算裂解率并用透射电镜观察布鲁菌菌壳的形态。结果显示,成功制备了布鲁菌菌壳,温控裂解质粒pBBRIMCS：：PR-PL-E对布鲁菌的裂解率为100％。透射电镜观察可见细菌内容物部分流出,细菌表面出现不同程度的皱缩,细胞形态发生变化。结果表明,本试验成功制备了粗糙型布鲁菌菌壳,初步研究了其基本特性,为下-步开展布鲁菌菌壳疫苗的研究奠定了基础。