Quantification of DNA of citrus huanglongbing pathogen in diseased leaves using competitive PCR

A quantification system for huanglongbing pathogen using a competitive polymerase chain reaction method and image-analyzing software were developed to obtain precise results. Significant differences in the quantity of pathogen were thus determined in leaves of two citrus cultivars commonly cultivated in southern Vietnam. Less pathogen-related DNA was detected from the tissue of citrus cultivars that are believed to be more tolerant than susceptible cultivars. The quantification system will be used in studies on pathogen proliferation and movement inside citrus tissue.     

蜂胶佐剂鸡毒支原体灭活疫苗的研制

收获鸡毒支原体培养液,甲醛灭活后加入一定比例蜂胶并进行乳化,制备3批蜂胶佐剂灭活疫苗。3批疫苗的物理性状、无菌检验、甲醛、硫柳汞含量等均符合《中华人民共和国兽用生物制品规程》(2000年版)中同类疫苗的基本要求;安全检验结果表明,受试鸡群无局部和全身反应,体温及采食量正常;效力检验结果表明,在免疫30d后攻毒,3批疫苗的免疫保护率均在60%以上。上述各指标显示,蜂胶佐剂鸡毒支原体灭活疫苗达到国家相关规定,为免疫预防鸡毒支原体病提供了新的方案。     

Enhancement of protective immune responses by oral vaccination with Saccharomyces cerevisiae expressing recombinant Actinobacillus pleuropneumoniae ApxIA or ApxIIA in mice

We previously induced protective immune response by oral immunization with yeast expressing the ApxIIA antigen. The ApxI antigen is also an important factor in the protection against Actinobacillus pleuropneumoniae serotype 5 infection; therefore, the protective immunity in mice following oral immunization with Saccharomyces cerevisiae expressing either ApxIA (group C) or ApxIIA (group D) alone or both (group E) was compared with that in two control groups (group A and B). The immunogenicity of the rApxIA antigen derived from the yeast was confirmed by a high survival rate and an ApxIA-specific IgG antibody response (p < 0.01). The highest systemic (IgG) and local (IgA) humoral immune responses to ApxIA and ApxIIA were detected in group E after the third immunization (p < 0.05). The levels of IL-1β and IL-6 after challenge with an A. pleuropneumoniae field isolate did not change significantly in the vaccinated groups. The level of TNF-α increased in a time-dependent manner in group E but was not significantly different after the challenge. After the challenge, the mice in group E had a significantly lower infectious burden and a higher level of protection than the mice in the other groups (p < 0.05). The survival rate in each group was closely correlated to the immune response and histopathological observations in the lung following the challenge. These results suggested that immunity to the ApxIA antigen is required for optimal protection.     

免疫佐剂研究进展

佐剂的主要作用是提高抗原（免疫原）的免疫原性和免疫反应的可持续性，它能引导机体的免疫系统对抗原产生体液免疫或细胞免疫反应。对佐剂的选择取决于免疫的目的，从用途上分，佐剂可分为试验用佐剂和疫苗用佐剂。前者主要用于特异性抗体的制备，而后者则作为疫苗的必要成分。文章主要介绍目前常用的几种佐剂包括铝盐佐剂、弗氏佐剂、免疫刺激复合物（ISCOM）、脂质体和CpG及其在科研和疫苗中的应用。     

邻烯丙基苯酚对植物病原真菌抑制机理初探

用含毒介质培养法测定了邻烯丙基苯酚(银果)对番茄灰霉病菌Botrytis cinerea、苹果腐烂病菌Valsa mali和小麦纹枯病菌Rhizoctonia cerealis的影响。通过培养观察发现,邻烯丙基苯酚可抑制番茄灰霉病菌分生孢子的产生、促进灰霉病菌菌核的形成及苹果腐烂病菌子囊壳的形成。光学显微观察表明:用50μg/mL的邻烯丙基苯酚处理番茄灰霉病菌菌丝后,菌丝伸长缓慢,分支间距缩短,分生孢子形成受到抑制。电镜观察表明:经邻烯丙基苯酚处理后,番茄灰霉病菌菌丝内液泡增多,苹果腐烂病菌菌丝细胞壁增厚,小麦纹枯病菌菌丝中内质网处泡囊增多。     

药用植物半夏细胞悬浮培养和植株再生体系建立研究

为了建立甘肃产药用植物半夏的细胞悬浮培养和植株再生体系,通过对其不同外质体筛选、愈伤组织诱导和悬浮培养的愈伤组织类型、激素水平、起始密度、震荡速率等影响因素以及细胞生长状态、生长曲线和pH值变化等指标的研究.结果表明:以叶柄为外质体,选择"松散型"愈伤组织和2×105个/mL的起始培养密度,在附加2,4-D 2.0 mg/L BA 0.5 mg/L NAA0.5 mg/L的1/2 MS培养基上培养,温度(23±2)℃,转速90 rpm,pH值6.0,黑暗培养为最适悬浮培养体系;经检测细胞生长曲线呈"S"型,培养液pH随着细胞的生长先上升后下降,18 d时细胞基数达到最大值;悬浮继代培养后,通过降低或停止震荡转速,在添加BA 0.5 mg/L NAA0.5 mg/L的MS液体和固体培养基上可诱导分化出芽和根,进一步形成完整的植株.     

非洲鸵鸟的雌雄鉴别研究

对鸵鸟进行早期的性别鉴定，可以确保期望的鸵鸟雌雄性别比例，雏鸟雌雄分群饲养，加快鸵鸟驯养进程，提高育雏成活率都有着重要意义。本研究采用翻肛法，对人工饲养的1～3月龄育雏期非洲鸵鸟进行试验与研究。结果表明，在1月龄时就可根据有无生殖交媾器及其形态、大小的差别进行雌雄鉴别，打破了通常认为鸵鸟在4月龄时才可以进行性别鉴定的传统做法，为非洲鸵鸟的饲养管理提供了有利的依据。     

狂犬病病毒糖/核蛋白"二价"DNA疫苗田间免疫效果评定

以狂犬病病毒糖、核蛋白“二价“DNA疫苗pVGN免疫3月龄至8岁龄家犬302条,分为2组:Ⅰ组201条,两侧股内侧肌注;Ⅱ组101条,单侧股内侧肌加单侧耳廓皮内联合注射.免疫3次,剂量为每条犬每次300μg,于试验的0d和35d分别进行.三免后21d用间接ELISA检测特异性抗体,Western-blot分析抗体组成,间接免疫荧光和小鼠中和试验测定抗体中和效价.结果显示,三免后抗体阳转率为58%,组间抗体水平差异不显著(P＞0.05),机体产生了抗糖蛋白、核蛋白2种特异性抗体,抗体稀释8～512倍后,每50μL可以中和100TCID50狂犬病病毒SRV9,个别稀释到2048倍仍具有中和作用,抗体稀释8～16倍后每15μL可中和120MICLD50狂犬病病毒CVS,少部分犬三免后抗体稀释16～32倍后能中和300MICLD50狂犬病病毒CVS.说明该疫苗具有良好的免疫原性,且诱生的抗体能发挥病毒中和作用.     

乳过氧化物酶对常见食品污染菌的抑制作用

分别采用分光光度法、菌体量法及孔扩散法研究了乳过氧化物酶（简写LP）对细菌和霉菌的抑菌活性及LP浓度、pH值和温度对抑菌活性的影响。结果表明：LP对于各供试菌均有很好的抑菌效果。其中，LP对铜绿假单胞菌、金黄色葡萄球菌和产黄青霉的抑制作用最显著，5μg／mL就能完全抑制他们的生长；在中性偏酸性环境中的抑菌活性比碱性环境的抑菌活性强；一定温度内处理不影响LP的抑菌活性；在中性条件下抑制供试革兰氏阴性菌和霉菌的能力强于Nisin。     

山东省小规模养鸡场沙门氏菌流行病学调查分析

对近年来山东省内鸡沙门氏菌病进行了调查,并对典型的沙门氏菌做了生化鉴定和药物敏感试验。调查表明沙门氏菌病在小规模养殖场的发生呈上升趋势,常与大肠杆菌病、新城疫和鸡球虫病混合感染。对所分离的沙门氏菌株鉴定表明,70%为副伤寒沙门氏菌,也有鸡白痢沙门氏菌的存在。药敏试验结果表明沙门氏菌对传统的防治细菌性药物产生了多重耐药性,这说明细菌耐药性的产生和发展与抗生素长期反复使用和盲目使用有密切的关系。本文为更有效地防控细菌性疫病提供科学依据。