鸡传染性法氏囊病病毒BC6/85株VP2基因的原核表达、纯化及鉴定

为获得可用于鸡传染性法氏囊病病毒(IBDV)抗体检测的重组抗原VP2蛋白,根据GenBank中发表的IBDV VP2序列设计一对特异性引物,应用RT-PCR技术克隆IBDV经典标准攻毒株(BC6/85株)的VP2基因,插入质粒pET-32a中构建重组表达质粒pET-32a-VP2,经IPTG诱导后获得了以包涵体形式表达的重组蛋白。重组蛋白纯化后,Western-blot检测表明具有良好的反应原性。本研究为下步建立IBDV抗体的间接ELISA方法及新型疫苗的研制奠定了基础。     

仔猪雷极氏普罗菲登斯菌的分离鉴定及系统进化分析

为了解猪雷极氏普罗菲登斯菌(P.rettgeri)的生物学特性、致病性及16SrRNA基因系统进化关系,从发生严重腹泻、血便的哺乳仔猪群的内脏器官中分离到1株病原菌,根据形态特征、培养特性、生化特性、16SrRNA基因序列分析鉴定为P.rettgeri。小鼠攻毒试验证实,该分离菌株对试验小鼠有较强致病力,哺乳仔猪回归试验可复制出与临床上相似的典型症状,并从发病死亡小鼠及哺乳仔猪中分离到攻毒菌株。系统进化分析表明,分离菌株与雷极氏普罗菲登斯菌系统进化关系最为密切,其16SrRNA基因序列与雷极氏普罗菲登斯菌代表菌株的同源性在97.3%~99.6%之间。药敏试验结果表明,分离菌株对头孢哌酮钠、头孢噻肟钠、头孢曲松钠、头孢唑啉、头孢呋肟、头孢吡肟、阿莫西林、链霉素、氨曲南、诺氟沙星、左氟沙星、恩诺沙星、卡那霉素、氨苄青霉素、米诺环素、链霉素、阿米卡星等多数药物敏感。首次报道了雷极氏普罗菲登斯菌可以引起哺乳仔猪严重腹泻,提示在仔猪腹泻中应注意该菌感染的诊断、监测和防控。     

Pathogenicity of a Strain of H5N6 Subtype Avian Influenza Virus in Ducks and Mice

To investigate the pathogenicity of A/Hero/Guangdong/C1/2013(H5N6), an AIV strain isolated from Heron on ducks and mice, pathogenicity of this new virus strain and changing of histopathology as well as a preliminary study on its biological characteristics were studied by virus challenges test via intranasal and eye-drop and in chicken via jugular vein injection.Results showed that the EID₅₀ of this strain of virus was 10^-8.16/0.1 mL in embryonated chicken eggs and the intravenous inoculation of pathogenic index (IVPI) was 2.76.In ducks and mice, the 50% lethal doses (LD₅₀) of it were determined to be 10^-4.0/0.2 mL and 10^-4.67/0.05 mL, respectively.Symptoms of infection included loss of appetite, depression, swollen head and tears after being infected with 10⁶ EID₅₀ per duck by intranasal and eye-drop administration.Most of ducks died 4 to 7 days post-infection, liver, lung and kidney still eliminated toxicants at day 7 post-infection.Anatomy showed symptoms of pericardial effusion, pulmonary congestion and kidney enlargement, while pathological section showed pathological change like karyopycnosis and inflammatory cell infiltration in heart, liver, kidney and spleen.Mice developed symptoms of infection like loss of appetite, depression, shaggy coat and ruffled coat after being infected with 5×10⁵ EID₅₀ per mouse by intranasal and eye-drop administration.Most of the infected mice died 5 to 7 days post-infection and only liver still eliminated toxicants at day 7 post-infection.Although organ anatomy showed no obvious pathological changes, pathological section showed pathological changes like karyopycnosis and inflammatory cell infiltration in heart, kidney and lung.Our research demonstrated that this H5N6 subtype AIV had a strong pathogenicity and could be defined as a highly pathogenic AIV strain as its IVPI was greater than 1.2.Our work laid a theory foundation for study, prevention and control of H5N6 subtype AIV.     

Prevalence of Type VI Secretion System in Spanish Campylobacter jejuni Isolates

Infections from Campylobacter jejuni pose a serious public health problem and are now considered the leading cause of foodborne bacterial gastroenteritis throughout the world. Sequencing of C. jejuni genomes has previously allowed a number of loci to be identified, which encode virulence factors that aid survival and pathogenicity. Recently, a Type VI secretion system (T6SS) consisting of 13 conserved genes was described in C. jejuni strains and recognised to promote pathogenicity and adaptation to the environment. In this study, we determined the presence of this T6SS in 63 Spanish C. jejuni isolates from the food chain and urban effluents using whole‐genome sequencing. Our findings demonstrated that nine (14%) strains harboured the 13 ORFs found in prototype strain C. jejuni 108. Further studies will be necessary to determine the prevalence and importance of T6SS‐positive C. jejuni strains.     

两种外源激素在白掌组织培养不同阶段的剂量研究

文章研究了不同浓度的细胞分裂素6-BA对白掌外植体诱导、愈伤组织增殖、不定芽增殖及生长素IBA对诱导生根的影响。结果表明：初代培养基以1／2MS CM100ml／L 蔗糖30g／L 琼脂6g／L 6-BA 1.0mg／L效果最好；在培养基MS NAA 0．1mg／L 蔗糖30g／L 琼脂6g／L中添加6-BA 1.0mg／L愈伤组织和不定芽的增殖倍数最高；在培养基1／2MS 活性炭2g／L 蔗糖30g／L 琼脂6g／L中添加2．0mg／L IBA可显著提高生根率。     

Inducing long-shoot growth for vegetative propagation of western larch

This study evaluated methods to release from suppression both short shoots on lower stems and developing buds on leaders of western larch (Larix occidentalis Nutt.) seedlings, in order to increase the number of long shoots suitable for stem-tip cuttings. Treatments included application of the cytokinin N-6-benzyladenine (BA), horizontal stem bending, and decapitation on container-grown 1.5-year-old seedling ortets. The rate of release of suppressed growth of short shoots on the basal stem segments increased from 15% to 83% after spraying with 200 ppm BA and doubled on unsprayed horizontally-bent stems. Syllepsis on the upper stems increased by 19% following decapitation and by 32% after a combination of decapitation and BA treatments. Although these treatments resulted in large increases in the numbers of long shoots available for stem cuttings, the rootability of BA-treated shoots needs assessing before use in operational programs.     

6-苄基腺嘌呤对甜柿次郎果实中糖、酸含量的影响

以甜柿次郎为试材,100￣200 mg/L的6-BA于花后10天喷果,结果表明:均提高了果实还原糖、可溶性糖、TSS含量及固酸比;促进果实淀粉降解;对可滴定酸含量影响不大。     

咖啡种质资源的引进、研究及利用

对引进保存的个咖啡种质进行种质特性和适应性研究及评价;对用部分种质的基因型作有性杂交,164获得份不同杂交组合种子实生苗材料进行筛选;推广小粒咖啡卡蒂莫(15CIFC7963F6)生产种植6 984hm2,取得显著经济效益。     

6BA和NAA对朱顶红组织培养的影响

以朱顶红品种为试材,在组织培养过程中,以鳞茎为外植体,研究6BA和NAA的不同浓度对其直接诱导再生植株的影响。结果表明:M S 1 m g/L的6BA 2 m g/L的NAA是直接诱导鳞茎再生植株的最好组合,而LS 2 m g/L的6BA 0.5 m g/LNAA是直接诱导鳞茎再生植株的理想培养基。