琼脂糖凝胶电泳检测烟粉虱Q型与B型微卫星位点BEM23的研究

近年来烟粉虱Q型和B型在国内外许多地区混合发生并造成危害,2种生物型的快速鉴定对于烟粉虱有效防控具有重要的指导意义。在前期研究基础上,使用琼脂糖凝胶电泳对2005—2009年山东各地采集的烟粉虱样品（139头Q型烟粉虱、239头B型烟粉虱）微卫星位点BEbi23进行了检测研究。结果表明,绝大多数Q型烟粉虱只扩增到约400bp的片段（占98．6％）,而多数B型烟粉虱扩增到的片段约200bp（占97．9％）。鉴于绝大多数Q型和B型烟粉虱分别只存在约400bp和约200bp产物片段,该方法可用于B型、Q型烟粉虱大量样品生物型的初步筛选。     

Yersinia enterocolitica in sheep - a high frequency of biotype 1A

Background

Pigs are regarded as the main reservoir for human pathogenic Yersinia enterocolitica, which is dominated by bioserotype 4/O:3. Other animals, including sheep, have occasionally been reported as carriers of pathogenic strains of Y. enterocolitica. To our knowledge, this is the first study performed in the Nordic countries in which the presence of Y. enterocolitica in sheep is investigated.

Methods

Tonsils and faecal samples collected from sheep slaughtered on the island Gotland (Sweden) from September 2010 through January 2011 were analysed for presence of Y. enterocolitica. In an attempt to maximize recovery, several cultural strategies were applied. Various non-selective media were used and different temperatures and durations of the enrichment were applied before subculturing on Cefsulodin Irgasan Novobiocin (CIN) agar. Presumptive Y. enterocolitica colonies were subjected to urease, API 20E and agglutination test. Yersinia enterocolitica isolates were biotyped, serotyped, and tested for pathogenicity using a TaqMan PCR directed towards the ail-gene that is associated with human pathogenic strains of Y. enterocolitica.

Results

The samples collected from 99 sheep yielded 567 presumptive Y. enterocolitica colonies. Eighty urease positive isolates, from 35 sheep, were identified as Y. enterocolitica by API 20E. Thirty-four of 35 further subtyped Y. enterocolitica isolates, all from faecal samples, belonged to biotype 1A serotype O:5, O:6. O:13,7 and O:10. One strain was Yersinia mollaretii serotype O:62. No human pathogenic strains of Y. enterocolitica were found in the investigated sheep. Other species identified were Y. kristensenii (n = 4), Y. frederiksenii/intermedia (n = 3), Providencia rettgeri (n = 2), Serratia marcescens (n = 1) and Raoultella ornithinolytica (n = 1).

Conclusions

This study does not support the hypothesis that sheep play an important role in transmission of the known human pathogenic Y. enterocolitica in the studied geographical region. However, because there are studies indicating that some strains of Y. enterocolitica biotype 1A may cause disease in humans, the relative importance of sheep as carriers of human pathogenic strains of Y. enterocolitica remains unclear. Tonsils do not appear to be favourable sites for Y. enterocolitica biotype 1A in sheep.     

安徽合肥地区烟粉虱生物型鉴定及其系统发育分析

利用mtDNA COI基因片段对安徽合肥地区烟粉虱生物型进行了鉴定及系统发育分析。结果表明,合肥地区所采集烟粉虱为Q型,且与云南昆明地区的烟粉虱种群同源性达到99.8%～100%,推测安徽合肥地区Q型烟粉虱很可能为外来入侵害虫,其发源地应该与云南昆明地区Q型烟粉虱一致。     

MN品系皮燕麦对E型麦二叉蚜的抗性评价

为了明确MN品系皮燕麦对甘肃流行E型麦二叉蚜的抗性,筛选优异的抗蚜种质资源,在田间3年成株期自然感染蚜量比值法表型抗性鉴定基础上,采用室内苗期人工接蚜、实验种群生命表法测定了12个MN品系皮燕麦对E型麦二叉蚜的抗生性。结果表明,E型麦二叉蚜成蚜在表型中抗品系MN10253上的成蚜寿命和总产蚜量显著低于表型中抗品系MN08243、低抗品系MN09103和中感品系MN09255,产蚜前期显著长于MN08243、MN09103和MN09255;在MN10253上的平均发育历期短于MN08243;在MN10253上的种群趋势指数显著低于MN08243、MN09103和MN09255;在MN10253和MN08243上的内禀增长率rm、周线增长率λ和净增值率R0显著低于MN09255,有翅蚜率显著高于MN09255。说明表型中抗品系MN10253对E型麦二叉蚜种群繁殖具有抑制作用。     

安徽省姜青枯假单胞菌生物型鉴定初报

根据海沃德制订鉴定青枯假单胞菌生物型的方法,对舒城、铜陵、桐城、临泉、阜阳、全椒、巢县、屯溪和休宁等9县市分得的32个菌株进行鉴定。其中4个菌株SC78、SC710、SC81和SC93能利用乳糖、麦芽糖和纤维二糖,不能利用甘露醇、山梨醇和甜醇,属生物型Ⅲ;其它28个菌株则相反,属生物型Ⅳ。生物型Ⅲ的4个菌株是由前作番茄、辣椒和茄子田中的姜瘟病株上分得的;它对姜株致病力较生物型Ⅳ弱。     

我国褐飞虱生物型监测初报

 我国为褐飞虱迁入地带，田间褐飞虱种群是由具有不同致害性的生物型个体所组成的混合体。所以，一个田间种群的生物型属性即为该种群优势个体的致害性。根据我们自1981-1991年逐年系统监测结果，浙江省田间褐飞虱种群的致害性在年度间有波动，但自1989年开始其致害性已稳定地属生物2。浙江省褐飞虱由生物型1转变为生物型2的过程，落后于南方的海南和广西省（区），比热带虫源地更迟。     

杨陵地区麦二叉蚜在小麦品种Amigo上的抗性鉴定

根据麦二叉蚜种下生物型分化特性 ,设计了小麦品种 Amigo的抗蚜性和麦二叉蚜生物型鉴定试验。分析了自然条件下小麦品种 Amigo对麦二叉蚜的出生率、死亡率和内秉增长率的影响 ,组建了自然条件下麦二叉蚜在小麦品种 Amigo上的生命表。以生命表中的内秉增长率和稳定年龄组配为指标进行生物型鉴定分析。结果表明 :1麦二叉蚜在 Amigo上的生存曲线、繁殖曲线同麦二叉蚜在其它品种上的表现一致 ,分别为 B型和偏峰曲线 ;2平均世代时间为 1 1 .7670 d,周限增长率为 1 .1 45 3 ;3种群的瞬时出生率为 0 .3 2 2 0 ,瞬时死亡率为 0 .1 846;4内秉增长率为 0 .1 3 5 7;5稳定年龄期组配成蚜比例为 3 7.64% ,若蚜为 62 .3 7% ,与二叉蚜在其它小麦品种上的参数差异不显著。参数分析表明 ,在 Amigo品种上的麦二叉蚜种群发展趋势是上升的 ,种群数量是增长的 ,可见杨陵地区麦二叉蚜既非 A、B,也非 C生物型 ,品种 Amigo不抗本地区麦二叉蚜     

Gliocladium virens生物型GVP对Rhizoctonia solani的抗生现象

Gliocladium virens生物型GVP寄生在Rhizoctonia solani的菌丝和菌核上。在光学显微镜和扫描电镜下,我们发现GVP的菌丝缠绕在寄主菌丝上侵入并在其内生长,形成附着胞,寄主菌丝原生质颗粒状或外溢以及有时呈丛枝状。在PDA平板上GVP产生的挥发性物质抑制寄主菌丝的生长和菌核的形成。GVP的三种供试培养滤液影响寄主菌丝生长和干重的降低,使细胞内含物外渗,以致崩解死亡。被寄生的寄主菌核的组织软化、不萌发。     

Investigation of bovine brucellosis in the Northeastern Turkey

Bovine brucellosis, caused by Brucella abortus, is a significant problem for both public and animal health in Turkey. This study was conducted on the calving seasons between 2001 and 2006. A total of 626 serum samples of cattle obtained from 27 herds with a history of abortions was examined for Brucella antibodies by RBPT, SAT and ELISA. Of the cattle sera analysed, 221 (35,30%) and 206 (32, 92%) and 247 (39,45%) were found to be positive by RBPT , SAT and ELISA, respectively. B. abortus was isolated from 48 (32,21%) of 149 lung samples and stomach contents of the aborted fetuses. Based on the biochemical tests and the agglutination tests with monospecific A and M antisera, only 3 of the isolates were found to be B. abortus biotype 1 and the remaining 45 were biotype 3. This study also revealed that the dominant biotype of B. abortus was biotype 3 in this region. The determination of the agents responsible for bovine brucellosis and serosurvey of this disease are expected to help better understanding of this zoonotic infection in this region and neighbouring countries.