大肠杆菌MM—3基因工程活菌苗免疫母猪血清及乳清中抗K_(88ac)及LTB抗体动态

以MM-3基因工程活菌苗口服免疫妊娠73d、83d、103d母猪各4头,口服及肌注免疫妊娠92d母猪各5头,用间接BA-ELISA法检测血清及乳清中IgG、IgA和IgM型抗K_(88ac)及LTB抗体的动态变化.结果表明,无论口服还是肌注免疫母猪,抗K_(88ac)及抗LTB抗体均极显著增高.肌注以IgG增加为主,口服以IgA增加为主.肌注免疫IgG型抗K_(88ac)抗体滴度极显著地高于口服免疫(P<0.01);口服免疫IgA型抗LTB抗体滴度显著高于肌注免疫(P<0.05).口服及肌注免疫乳清中抗K_(88ac)及抗LTB抗体滴度很高,达1:3200～204800,但在1周内即降低,约减少一半(约3～5个滴度),2～3周内各型抗体下降缓慢,维持在对照组周内水平,4周后达最低水平.妊娠不同时期口服免疫,其血清中抗K_(88ac)抗体的动态变化相似,但乳汁中抗体则差异非常明显,妊娠83d和92d免疫组IgG、IgA和IgM均显著增加,且高于103d组(P<0.01)和73d组(P<0.05).口服免疫的最佳时间为分娩前26～30d,肌注免疫最佳免疫时间为分娩前21d.     

鸡马立克病CVI988疫苗不同接种部位对免疫效果的影响

探讨鸡马立克病CVI988疫苗不同的接种部位对免疫效果的影响,将96只1日龄海兰褐公雏鸡随机分成对照组(C)、腹腔注射接种组(PI)和颈部皮下接种组(HI),C组腹腔注射0.2mL疫苗稀释液,PI组和HI组注射0.2mL CVI988疫苗。在第3、6、10、15、20、26、35、45天对3组各4只鸡进行心脏采血,制作血涂片,分别进行ANAE和甲基绿-派洛宁染色,观察血液中阳性B淋巴细胞和T淋巴细胞百分率的变化。结果显示,在免疫早期(3日龄～6日龄),免疫组的阳性T淋巴细胞显著低于对照组,而阳性B淋巴细胞在第3天就显著高于对照组;在免疫中后期,免疫组的阳性T淋巴细胞和B淋巴细胞基本都显著高于对照组;并且PI组的阳性T淋巴细胞高于或显著高于HI组,阳性B淋巴细胞在第15天显著高于HI组。由此可见,CVI988疫苗接种第3天产生体液免疫效应,10d后细胞免疫效应高于对照组,即早期免疫效果主要靠体液免疫,腹部免疫接种效果优于颈部免疫,为马立克病更有效的免疫接种提供了理论依据。     

免疫鸡毒支原体F弱毒株对SPF鸡Bu-1a~+ B、TCRγδ~+ CD3~+T细胞及血清IgM、IgG、IgA的影响

分别以活菌浓度为109(A组)、106(B组)ccu/mL的(MG)F株及生理盐水(C组)点眼接种SPF鸡,采用流式细胞技术及ELISA方法对免疫前后外周血淋巴细胞(PBL)中Bu-1a+B、TCRγδ+CD3+T细胞比例及血清IgM、IgG、IgA的动态变化规律进行研究。结果显示各组Bu-1a+B/PBL于免疫后5、7d由高至低依次为A、B和C组,且各组差异显著(P0.05);A、B组TCRγδ+CD3+T/PBL于免疫后3d略有升高且比值较接近,都高于C组,但差异不显著(P0.05);各组IgM于免疫后7、14和21d差异显著(P0.05),IgG于免疫后14、21和28d差异显著(P0.05),IgA于免疫后28d差异显著(P0.05),由高至低依次为A、B、C组。研究结果表明,免疫(MG)F株可较好的提高Bu-1a+B、血清IgM、IgG、IgA介导的体液免疫作用,且(MG)F株活菌浓度与Bu-1a+B/PBL比值、血清IgM、IgG、IgA浓度呈正相关;但免疫(MG)F株不能显著提高鸡外周血TCRγδ+CD3+T/PBL比值,且(MG)F株活菌浓度与TCRγδ+CD3+T/PBL比值无明显相关性。     

预防仔猪黄、白痢双价工程菌苗MM-3的免疫效果观察

本文报告了用遗传工程技术构建、能合成粘附素K88与无毒肠毒素LT-B两种抗原的菌苗MM-3进行免疫试验的结果。菌苗无毒安全,超量使用亦未见到副作用。免疾后能引起机体的应答反应,母猪血及初乳中均可测得抗体,初乳中抗体效价较血中高。在用强毒的肠毒素性大肠杆菌人工攻击仔猪的试验中,对照组死亡率为74.2%,口服免疫组与注射免疫组死亡率分别为1.0%与6.5%。三年内在多个猪场、对上万头仔猪进行菌苗效果观察,未免疾对照组腹泻发病率为55—80%,免疫后降至10—25%,未免疫对照组腹泻死亡率为7—40%,免疫后仅为1—3%。试验观察至仔猪生后30日,菌苗不仅可预防黄痢、亦能预防白痢发生。     

妊娠母猪免疫高致病性猪繁殖与呼吸综合征疫苗对仔猪免疫功能的影响

规模化猪场猪繁殖与呼吸综合征病毒（PRRSV）呈持续性感染,给养猪业造成的损失最为严重。部分规模化猪场未实施切实的猪繁殖与呼吸综合征疫苗免疫,呈慢性和潜伏感染,作者现场对妊娠母猪接种高致病性猪繁殖与呼吸综合征（HP-PRRS）减毒活疫苗（TJM-F92株）,旨在从体液免疫、细胞免疫、非特异性免疫功能角度探讨妊娠母猪接种疫苗后对仔猪免疫功能的影响。选取妊娠60 d母猪随机分为A、B 2组,A组母猪接种HP-PRRS减毒活疫苗（TJM-F92株）,B组母猪接种等量生理盐水,2组所产仔猪于10、20、30日龄时检测PRRSV、猪瘟病毒（CSFV）、猪伪狂犬病病毒（PRV） 母源抗体,以MTT法测定外周血T、B淋巴细胞转化率、以琼脂平板法测定血清溶菌酶含量、以Griess试剂法测定NO含量。试验结果表明,妊娠母猪免疫HP-PRRS减毒活疫苗（TJM-F92株）后,其所产10日龄仔猪PRRSV母源抗体水平显著高于对照组仔猪（P＜0.05）,仔猪CSFV阻断抗体极显著增高（P＜0.01）,20日龄仔猪PRV感染抗体显著下降（P＜0.05）;免疫组和对照组所产仔猪的T、B淋巴细胞转化率及NO、溶菌酶含量均无显著差异（P＞0.05）。提示,妊娠母猪免疫HP-PRRS减毒活疫苗（TJM-F92株）,对所产仔猪非特异性免疫功能和T、B免疫功能均无免疫抑制作用,仔猪抗PRRSV母源抗体、抗CSFV阻断抗体均显著增高且PRV感染抗体降低。     

鸡毒支原体F弱毒疫苗株细胞免疫特性研究

为了解鸡毒支原体（Mycoplasma gallisepticum,MG）F弱毒疫苗株的细胞免疫特性,分别以活菌浓度为109（A组）、106（B组）ccu/mL的MG F株及生理盐水（C组）点眼接种SPF鸡,采用流式细胞技术及T淋巴细胞增殖试验对免疫前后淋巴细胞亚类Th/T、Tc/T、Th/Tc及刺激指数（SI）的动态变化规律进行研究。结果显示免疫后A、B组的Th/T、Tc/T、SI明显升高,其中Th/T于d5、d7,Tc/T、SI于d7、d14,A组显著高于B组（P〈0.05）。研究结果表明,免疫MG F株可较好的提高鸡的细胞免疫,且MG F株活菌浓度与接种鸡外周血Th/T、Tc/T、SI呈正相关。     

复方中草药免疫增强剂对蛋鸡免疫效果的研究

选用3种中草药配方，采用1％、1．5％、2％3个添加水平，进行9个试验组和1个对照组比较研究。对试验鸡的45d免疫器官质量和T、B淋巴细胞进行检查，对不同日龄鸡新城疫（ND）和传染性法氏囊（IBD）的抗体效价、中性粒细胞吞噬功能和T淋巴细胞转化率进行检测。结果表明，试验组脾质量、法氏囊质量及T、B淋巴细胞相对数高于对照组（P〈0．05），以配方B为最高，其次为配方A。试验组抗体效价、中性粒细胞吞噬率、吞噬指数和T淋巴细胞转化率高于对照组（P〈0．05），其中ND抗体效价、IBD抗体效价20d前组间差异不显著，34d后组间差异趋于显著。54d和126d时，A、B、C3配方中性粒细胞吞噬率和吞噬指数组间差异显著（P〈0．05或P〈0．01）；T淋巴细胞转化率组间也存在极显著差异，其中配方A中的1组具有明显优势。重复试验结果基本相似。     

大肠杆菌MM—3基因工程活菌苗免疫母猪所产仔猪抗K_(88ac)及抗LTB抗体动态

应用BA-ELISA,分别检测了用大肠杆菌MM-3基因工程活菌苗免疫妊娠92d母猪所产仔猪血清和消化液中抗K_(88ac)及抗LTB抗体的动态消长.结果表明,新生仔猪在吃初乳后24h内,血清及消化液中抗K_(88ac)及抗LTB抗体水平均很高,但以后逐渐下降,1周后IgM、2～3周后IgA、3～4周后IgG分别下降到最低水平;仔猪35日龄时,抗体水平有所回升.消化液中抗体水平比血清中抗体水平下降快,并与母体乳汁中的抗体水平呈正相关关系.     

日粮中不同蛋白水平对妊娠母猪繁殖性能的影响

研究旨在通过对妊娠母猪繁殖性能为期一年的监控,探讨不同蛋白水平对妊娠母猪繁殖性能的影响,为妊娠母猪养殖提供参考。从2014年9月~2015年9月对湖南某猪场3个妊娠母猪舍母猪的繁殖性能进行测定,3个妊娠母猪舍分为A、B、C组,每组长期保持150~200头母猪,其中A组、B组和C组分别饲喂蛋白水平为14.01%、14.35%和14.71%的日粮。结果表明:(1)B组平均总产仔数较A组和C组分别提高了5.1%(P<0.05)和2.4%(P<0.05),A组稍低于C组,差异不显著(P>0.05);(2)C组平均窝活产仔数较A组提高了5.3%(P<0.05),C组高于B组,差异不显著(P>0.05);(3)C组平均窝弱仔数较B组降低了35.52%(P<0.05),C组较A组降低10.9%,差异不显著(P>0.05);(4)C组平均窝死产仔数较B组降低了42.67%(P<0.05),C组较A组降低29.51%,差异不显著(P>0.05);(5)随着蛋白水平的升高窝木乃伊数没有显著的变化趋势(P>0.05)。结果表明,在妊娠母猪饲养过程中,适当提高日粮中蛋白水平至14.71%可以有效改善繁殖性能,获得较多的健仔数,为养殖生产带来更大的经济效益。     

乳酸杆菌DNA对鸡新城疫油苗和禽流感油苗免疫增强作用的研究

本试验提取乳酸杆菌L.caseiZhang的DNA作佐剂,按每只鸡100ug剂量添加到新城疫油苗及禽流感病毒H5亚型油苗中。新城疫和禽流感试验分别设空白对照组(Ⅰ组)、无佐剂疫苗组(Ⅱ组)、细菌核酸佐剂组(Ⅲ组)、弗氏完全佐剂组(Ⅳ组)、弗氏完全佐剂核酸免疫协同组(Ⅴ组)5组进行免疫,分别于15和28日龄首免,两周后二免。二免后每周采样用血凝及血凝抑制法检测血清抗体水平,并用MTT法检测脾脏T淋巴细胞增殖反应。结果显示,添加核酸组鸡HI抗体和T淋巴细胞增殖反应均极显著高于单独免疫疫苗组(P<0.01);而免疫组均极显著高于空白对照组(P<0.01);细菌核酸组HI抗体略高于弗氏完全佐剂组,但T淋巴细胞转化率极显著高于弗氏完全佐剂组(P<0.01);同时弗氏完全佐剂核酸免疫协同组与核酸组无显著性差异。由此得出,乳酸杆菌L.caseiZhangDNA对新城疫油苗和禽流感病毒H5亚型油苗具有免疫增强作用;乳酸杆菌L.caseiZhangDNA与弗氏完全佐剂无明显的免疫协同作用。     

Oral efficacy of Vero cell attenuated porcine epidemic diarrhea virus DR13 strain

A Vero cell attenuated porcine epidemic diarrhea virus (PEDV) strain, DR13, was distinguished from wild-type PEDV using restriction enzyme fragment length polymorphism (RFLP). Cell attenuated DR13 was orally or intramuscularly (IM) administered to late-term pregnant sows, and mortality resulting from the highly virulent PEDV challenge was investigated in passively immunized suckling piglets of the two different groups. The mortality rate of the oral group (13%) was lower than that of the IM group (60%). In particular, the concentration of IgA against PEDV was higher in piglets of sows in the oral group, compared to the IM group. The attenuated DR13 virus remained safe, even after three backpassages in piglets. The findings of this study support the theory that the Vero cell attenuated DR13 virus may be applied as an oral vaccine for inducing specific immunity in late-term pregnant sows with a high margin of protection against PEDV infection.     

Induction of lactogenic immunity to transmissible gastroenteritis virus of swine using an attenuated coronavirus mutant able to survive in the physicochemical environment of the digestive tract.

A transmissible gastroenteritis (TGE) coronavirus mutant (188-SG), selected as attenuated and resistant to acidity and proteases of the digestive tract of adult pigs, was used as vaccine ("Nouzilly strain") in sows to protect suckling piglets against a challenge exposure carried out with a highly virulent TGEV strain. The pregnant sows were immunized once (42-49 days before farrowing) or twice (42-49 and 7-15 days before farrowing) by the oral, intramuscular or conjunctival route with the 188-SG strain. Sows exposed to virulent TGEV in the field and experimentally infected sows (two oral inoculations during pregnancy) were used as positive controls leading to high protection. The neutralizing antibody response to vaccination and/or infection was studied in serum and milk. No protection against mortality was observed in the litters of (1) the nine seronegative, susceptible sows, with piglet mortality of 65/70, (2) the seven once orally vaccinated sows, with mortality of 44/54, (3) the seven sows vaccinated twice by the conjunctival route, with mortality of 55/76. Moderate protection was observed in (1) the eight sows vaccinated intramuscularly twice with piglet mortality of 36/90, (2) the seven orally and intramuscularly vaccinated sows with piglet mortality of 31/51. In of 3 contrast, improved protection was observed in (1) the 10 sows vaccinated twice orally, with piglet mortality of 23/95, (2) the four naturally infected sows with piglet mortality of 6/41, (3) the six sows experimentally infected with virulent TGEV with piglet mortality of 1/59. No correlation was found between neutralizing antibodies titers in serum and milk and protection rate of the piglets. The results indicate that relative protective lactogenic immunity against TGEV is induced only by repeated ingestion of the attenuated 188-SG strain of TGEV.     

怀牛膝多糖对雏鸡疫苗免疫效果的影响

150羽14日龄蛋公鸡随机均分成3组,用新支二联弱毒苗点眼滴鼻免疫的同时,2个试验组分别肌肉注射高、低剂量的怀牛膝多糖溶液,对照组注射生理盐水,每天注射1次,连续注射3次。分别于免疫后第7、14、21、28、35和42天各组随机抽取8只鸡翼下静脉采血,分离血清,用微量法测定新城疫血凝抑制（HI）抗体效价,于免疫后第10、20、30、40和50天每组随机抽取5只鸡心脏采血,分离淋巴细胞,用MTT法测定淋巴细胞增殖的动态变化,流式细胞仪双染色法检测CD^4＋、CD^8＋T淋巴细胞含量,并放血致死称取体重和胸腺、脾脏、法氏囊的质量,计算器官指数。结果表明,怀牛膝多糖高剂量组的HI抗体效价、CD^4＋/CD^8＋比值和免疫器官指数都明显高于对照组,并且高剂量怀牛膝多糖可以显著促进T淋巴细胞增殖。提示怀牛膝多糖对鸡新支二联疫苗的免疫效果有明显的增强作用。     

Vaccination of sows against type 2 Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) before artificial insemination protects against type 2 PRRSV challenge but does not protect against type 1 PRRSV challenge in late gestation

The objective of the present study was to determine the effects of the commercially available type 2 Porcine Reproductive and Respiratory Syndrome Virus (PRRSV)-based modified live vaccine against type 1 and type 2 PRRSV challenge in pregnant sows. Half of the sows in the study were vaccinated with a type 2 PRRSV-based vaccine 4 weeks prior to artificial insemination while the other half remained non-vaccinated. Sows were then challenged intranasally with type 1 or type 2 PRRSV at 93 days of gestation. The sows which received the type 2 PRRSV-based vaccine followed by type 2 PRRSV challenge had significantly higher neutralizing antibody titers against type 2 PRRSV than they did against type 1 PRRSV. These same sows had higher frequencies of IFN-γ-secreting cells when stimulated with type 2 PRRSV compared to those stimulated with type 1 PRRSV. Subsequent virological evaluation demonstrated that the type 2 PRRSV-based vaccine reduced the type 2 PRRSV load but not the type 1 PRRSV load present in the blood of the sows. Additionally, vaccination of pregnant sows with the type 2 PRRSV-based vaccine effectively reduced the level of type 2 PRRSV nucleic acids observed in fetal tissues from type 2 PRRSV-challenged sows but did not reduce the level of type 1 PRRSV nucleic acid observed in fetal tissues from type 1 PRRSV-challenged sows. This study demonstrates that the vaccination of pregnant sows with the type 2 PRRSV-based vaccine protects against type 2 PRRSV challenge but does not protect against type 1 PRRSV challenge.     

Efficacy of a novel virulence gene-deleted Salmonella Typhimurium vaccine for protection against Salmonella infections in growing piglets

We have previously developed a novel attenuated Salmonella Typhimurium (S. Typhimurium) ΔcpxR Δlon vaccine. This study was carried out to examine whether this vaccine could effectively protect growing piglets against Salmonella infection. Attenuated S. Typhimurium secreting the B subunit of Escherichia coli heat-labile enterotoxin was also used as a mucosal adjuvant. Pregnant sows in groups A and B were primed and boosted with the vaccine and mucosal adjuvant, whereas sows in groups C, D and E received PBS. Piglets in groups A and C were intramuscularly primed with formalin-inactivated vaccine and orally boosted with live vaccine, while piglets in groups B, D and E received PBS. Piglets in groups A, B, C, and D were challenged with a wild type virulent S. Typhimurium at the 11th weeks of age. Colostrum sIgA and IgG titers in vaccinated groups A and B sows were approximately 50 and 40 times higher than those of non-vaccinated groups C, D and E sows (P < 0.001). Serum IgG titers of group A piglets were also significantly higher than those of groups D and E piglets during the study (P < 0.001). Furthermore, no clinical signs were observed in group A piglets during the entire experimental period after the challenge, while diarrhea was observed in many of the piglets in groups B, C, and D. No Salmonella was isolated from fecal samples of the groups A and C piglets on day 14 after challenge, whereas the challenge strain was isolated from several piglets in groups B and D. These results indicate that vaccination of the piglets with the vaccine and mucosal adjuvant in addition to vaccination of their sows induced effective protection against Salmonella infections in the growing piglets.     

Development of a novel live vaccine delivering enterotoxigenic Escherichia coli fimbrial antigens to prevent post-weaning diarrhea in piglets

The efficacy of a novel, live delivery vaccine was examined for protection against post-weaning diarrhea in pigs. An expression/secretion plasmid harboring genes encoding enterotoxigenic Escherichia coli K88ab, K88ac, FedA and FedF fimbriae was constructed and harbored in an attenuated Salmonella, which was used as the vaccine candidate. Groups A (n=3) and B (n=3) sows were orally immunized with the candidate vaccine and PBS as a control, respectively, at 8 and 11 weeks of pregnancy. All group piglets were challenged with two challenge strains at 5-week-old. All immunized sows had significantly increased IgG and IgA levels in both serum and colostrum to individual adhesins compared to the control (p ≤ 0.05). Immune response in Group A piglets were significantly increased (p ≤ 0.05). Furthermore, no clinical signs were observed in Group A piglets after the challenge and no challenge strains were detected in rectal swabs, while diarrhea was observed in 47.8% control piglets and challenge strains were isolated from all the diarrheic piglets. These results show that immune response of sucking piglets can maintain at higher levels through the milk of the immunized sows and vaccination of sows with the candidate may protect colibacillosis in weaned piglets.     

An evaluation in pigs of Nobi-Vac AR and an experimental atrophic rhinitis vaccine containing P multocida DNT-toxoid and B bronchiseptica

The trial involved eight large white sows obtained from a closed experimental specific pathogen free herd. Four sows (two each for an experimental vaccine and for Nobi-Vac AR) were vaccinated twice (eight weeks and two weeks before parturition) with 2 ml of vaccine administered intramuscularly. Two unvaccinated sows were used as an infected control group and two unvaccinated sows served as an uninfected control group. Forty-six piglets (28 from vaccinated sows and 18 from unvaccinated sows) were challenged by intranasal instillation of Bordetella bronchiseptica at two days of age and Pasteurella multocida type D, dermonecrotic toxin at seven days of age. Among the infected control group some piglets died and there were clinical signs of pneumonia and severe turbinate atrophy. In the vaccinated groups the results showed that immunisation of the pregnant sows had provided a good level of antibodies, which were transmitted to their offspring. There was a significant reduction in the clinical signs and no lesions were observed in the group vaccinated with the experimental vaccine and only moderate atrophy of the turbinates in the Nobi-Vac AR group. B bronchiseptica and P multocida were never recovered from the lungs of the vaccinated groups and in the nasal cavities their frequency declined with age.     

曲普瑞林对初产母猪定时输精效果的影响

为探讨曲普瑞林对初产母猪定时输精效果的影响,本实验选择健康、体况相近的产后21 d断奶的初产母猪81头,随机分为对照组、生理盐水组、戈那瑞林组和曲普瑞林组。对照组母猪断奶后进行发情鉴定并适时输精,其余3组母猪断奶后24 h注射孕马血清促性腺激素(PMSG),72 h后分别肌肉注射生理盐水2 mL、戈那瑞林100μg、曲普瑞林200μg,间隔24 h、40 h进行定时输精。统计各组母猪发情率、卵泡直径、激素浓度和繁殖性能。结果显示:曲普瑞林组母猪断奶后7 d内发情率(88.46%)最高(P>0.05),卵泡直径在第4天达到最大并高于其他各组(P<0.05);曲普瑞林组的参繁配种率高于对照组(P<0.05),批次妊娠率较对照组有提高趋势(P>0.05),窝产总仔数(11.88头)高于生理盐水组(P<0.05),窝产活仔数为10.13头,与生理盐水组差异不显著,曲普瑞林组的仔猪指数较生理盐水组提高144头(P>0.05)。综上,曲普瑞林应用于定时输精程序可提高初产母猪的繁殖性能及利用率。