熊蜂（Bombus lucorum）微孢子虫的初步研究

在国内捕获野生的熊蜂(B.lucorum)蜂王,调查发现其微孢子虫的感染率为27.61%,死亡率为0.61%。在饲养过程中,感染严重的蜂王大多未能产卵就死亡,有的即使产了卵不久也便死亡;中度感染的蜂王大多推迟产卵;轻度感染的蜂王同健康蜂王一样能正常产卵。从熊蜂(B.lu-corum)蜂王提取的微孢子虫在光学显微镜下观察,呈卵圆状,带有蓝色折光;在扫描电镜下观察,孢子的表面较光滑,未发现任何特征型结构。     

熊蜂微孢子虫对熊蜂的危害

在室内研究了熊蜂微孢子虫对熊蜂的危害,结果得出:N.bombi对不同B.lucorum蜂群的同日龄工蜂的感染率差异显著,说明熊蜂个体间抗微孢子虫病的能力不同;微孢子虫感染的工蜂幼虫、工蜂蛹、成年工蜂以及蜂王没有呈现任何能诊断的特有外部症状.感病蜂王平均产卵力降低,比健康蜂王平均推迟2～3天产卵,被感染的子代蜂王比健康蜂王推迟2～4天产卵,产卵力也降低,感病蜂王产的卵未发现感染微孢子虫,说明熊蜂微孢子虫不是通过垂直传播的.     

应用PCR技术快速鉴定熊蜂微孢子虫Nosema bombi

基于熊蜂微孢子虫16SrRNA基因序列设计了1对引物,并对引物退火温度和引物浓度等反应条件进行了优化。对所建立方法的敏感性、特异性和稳定性进行了验证后,使用该方法对40份样品进行检测。结果显示,本研究建立了一种能够特异、敏感鉴定熊蜂微孢子虫的PCR方法,对熊蜂微孢子虫总DNA的敏感性达到2.86×10-5 mg/L,可以将熊蜂微孢子虫从西方蜜蜂微孢子虫和东方蜜蜂微孢子等其他可以感染熊蜂的寄生虫中区分出来,具有良好的特异性和稳定性。通过对40份熊蜂样品进行检测结果表明,整个检测过程可以在4h内完成并具有良好的适用性。本研究建立的熊蜂微孢子虫检测方法可用于进境熊蜂的检验检疫。     

环介导等温扩增法检测熊蜂中的微孢子虫

为快速检测进口熊蜂中的微孢子虫,建立了环介导等温扩增技术(Loop-mediated isothermal amplifi cation,LAMP)。针对熊蜂微孢子虫核糖体保守基因设计LAMP引物,以熊蜂微孢子虫DNA、家蚕微孢子虫DNA、蝗虫微孢子虫DNA、兔脑炎微孢子虫DNA作为LAMP反应的模板,分别采用浊度法和显色法验证LAMP引物的特异性;并将含微孢子虫基因的质粒模板10倍梯度稀释,考察方法的敏感性。结果表明,LAMP法能有效、特异地检测出熊蜂寄生微孢子虫DNA,灵敏度比PCR法高10倍。该方法简单、快速、敏感,可应用于熊蜂寄生微孢子虫的便捷检测中。     

东方蜜蜂微孢子虫对密林熊蜂的致病机理

【研究目的】东方蜜蜂微孢子虫(Nosema ceranae)是一种细胞内专性寄生的微孢子虫,广泛寄生于东方蜜蜂(Apis cerana)和西方蜜蜂(Apis mellifera),不仅是危害蜜蜂的主要病原物之一,而且近年来国内外报道发现N.ceranae也感染重要经济昆虫-熊蜂(Bombus Latreille);【方法】采用传统生物学和电镜超微结构观察结合qPCR定量分析对N.ceranae在密林熊蜂上的致病机理进行了探讨;【结果】感染初期工蜂除取食减少和行动迟缓外无明显外观染病特征,感染后期工蜂萎靡,衰弱,飞翔无力。解剖后镜检发现中肠仅存少量孢子,但充满大量的细菌;熊蜂肠道组织切片发现N.ceranae主要经肠绒毛侵染中肠上皮细胞,核膨大并变形、线粒体体积变小甚至解体,内质网紊乱,但孢子只侵染寄主细胞质而不侵入细胞核,最终因线粒体解体,细胞破裂而导致死亡;qPCR定量分析得出在接种的3⁴ d中肠和脂肪体中N.ceranae的感染量达到最高值,其他组织则基本未检测到;【结论】根据研究并结合前人工作,认为N.ceranae侵染熊蜂的病理过程是从中肠细胞的病理变化开始的,最后导致寄主细胞的碎裂、死亡,这一过程逐渐扩大至寄主的整个组织、器官,以致其功能丧失,严重的会导致熊蜂死亡。     

熊蜂（Bombus spp.）的授粉特性及其人工饲养

本文通过对Bombus lucorum和Bombus terrestris两个熊蜂种的室内饲养及温室蔬菜授粉试验,分析了熊蜂的授粉特性、人工饲养技巧和应用前景.     

蜜蜂微孢子虫病感染情况调查与分析

为了解吉林省蜜蜂微孢子虫的感染情况、传播动态及流行病学特点,在舒兰、安图、集安、敦化和蛟河等5个地区共50个蜂场采集蜜蜂样品,采用蜜蜂消化道涂片检验法进行蜜蜂微孢子虫病的感染情况调查。结果上述地区蜂场均检出有蜜蜂微孢子虫感染,总检出率为32%。调查结果表明,吉林省主要养蜂地区饲养蜂群中存在蜜蜂微孢子虫感染。     

家蚕微孢子虫(Nosema bombycis)与其它微孢子虫及真菌的进化关系

综述了应用分子生物学和生物信息学对家蚕微孢子虫系统发育的研究进展,以及多菌灵等苯并咪唑类杀真菌剂对微孢子虫和真菌的抑制作用,认为研究家蚕微孢子虫和真菌的进化关系对家蚕微粒子病的控制技术研究具有重要参考价值。     

脑炎微孢子虫属3种微孢子虫的虫株未能感染食用动物

研究了脑炎微孢子虫属最常见的3种微孢子虫的虫株对于食用动物包括猪,牛,鸡,和火鸡的感染力.动物经口接种孢子后用2种方法来检测是否被感染,一种方法是在每日粪样中检测孢子,另一种方法是在动物接种21d后的器官组织学检查.尽管每种虫种的接种量高迭2×10~6至2×10~7个孢子,但是在每种动物都没有检测到感染.结果表明,本试验中所用的脑炎微孢子虫属的3种微孢子虫虫株缺乏对猪,牛,鸠和火鸡的感染力.     

熊蜂为温室西红柿授粉的效果研究

通过对温室西红柿应用熊蜂授粉、人工喷施激素和空白对照的比较研究 ,表明熊蜂组在产量上比激素组和对照组分别增加了 5 9 2 6 %和 142 15 % ,而畸形果率却分别下降了 6 7 41%和 83 6 8% ,利用熊蜂授粉还可以缩短果实成熟期 ,提高维生素C含量和总糖含量 ,降低酸度 ,改善果实品质。     

蝗虫微孢子虫病在草原蝗虫中扩散传播的研究

检验了是同孢子虫在草原蝗虫中感染情况,结果是在长时间和近距离时感染率高。     

蝗虫微孢子虫病在草原蝗虫中扩散传播的研究

检验了蝗虫微孢子虫在草原蝗虫中感染情况,结果是在长时间和近距离时感染率高.     

Investigation of Cryptosporidium spp. and Giardia spp. in a Public Water‐Treatment System

The objective of this study was to investigate the occurrence of Cryptosporidium spp. and Giardia spp. in a public water‐treatment system and to relate the results to physical, chemical, bacteriological and climate parameters. From March to September 2006, 30 samples, 15 of raw water and 15 of treated water, were examined by membrane filtration and direct immunofluorescence (Merifluor). For each sample, a volume of 1000 l was collected. Of the raw‐water samples, 26.6% were positive for Cryptosporidium (mean concentration of 0.15 oocysts/l), and 6.66% were positive for Giardia (concentration of 0.2 cysts/l); 13.33% of the samples were positive for both (mean concentrations of 0.06 oocysts/l and 0.026 cysts/l respectively). All the samples of treated water were negative. There was no correlation (P < 0.05) between the presence of protozoans in the raw water and the parameters measured. The finding of Giardia and Cryptosporidium in raw water indicates that the water sources are contaminated. Considering that giardiasis is prevalent in the population and that Cryptosporidium has recognized zoonotic potential, long‐term monitoring at critical points of the system is necessary to guarantee that the water will not be a vehicle for transmission of these protozoans.     

Evidence‐based considerations for control of Parascaris spp. infections in horses

Parascaris spp. infection is virtually ubiquitous in young foals and worm burdens can achieve high numbers. The most important disease manifestation is impaction of the small intestine, which occurs in a small proportion of infected foals but is associated with a guarded prognosis for survival. Control of Parascaris spp. is complicated by emerging resistance to currently available anthelmintic drug classes. Resistance to macrocyclic lactones has been reported worldwide and a few studies have also documented signs of resistance to pyrantel salts and benzimidazoles. Foals generally develop immunity to Parascaris spp. parasites around age 6 months, but a proportion of weanlings and yearlings can harbour smaller burdens at age 8–10 months. Older horses have occasionally been reported with substantial ascarid burdens as well. Qualitative detection of ascarid eggs has good diagnostic value whereas an actual egg count does not correlate well with the size of the worm burden. A recent investigation documented the applicability of a transabdominal ultrasound technique for semiquantitatively monitoring ascarid burdens in foals. Control of ascarids is complicated by the limited drug classes available for treating this parasite, and by the fact that foals are often concurrently infected with strongyles. In many cases, none of the 3 available anthelmintic classes are simultaneously effective against both parasite groups, so close monitoring is required to select the most appropriate anthelmintic in each case.     

一株产赖氨酸芽孢杆菌的筛选

87株芽孢杆菌经过2次菌液上清液赖氨酸含量测定,筛选出1株赖氨酸产量较高的菌株YB83,其在LB上清发酵液中赖氨酸含量达186.85μg/mL,比对照组提高27.68%,该菌通过菌落形态、生理生化特征和分子生物学鉴定为枯草芽孢杆菌。     

Risk factors for Brucella spp. infection In dairy cattle farms in Asmara, State of Eritrea

A cross-sectional study was conducted to identify risk factors for herd infection by Brucella spp. in dairy cattle in the suburbs of Asmara, Eritrea. Data were collected from 64 herds, randomly selected from a total of 99 herds with a minimum herd size of 9 cows. A questionnaire was used to gather data on management, hygiene and herd structure. Serum samples collected from all pregnant heifers, cows and bulls, were screened for Brucella infection by the Rose Bengal test (RBT), and all RBT-positive sera re-tested with the complement-fixation test (CFT) for confirmation. A seropositive herd was defined as one in which at least one animal tested positive in the CFT. There were 23 (36%) positive herds among the 64 studied. Both multiple logistic and multiple betabinomial regression modeling were used to analyze the data. Mixed-breed herds, compared to single (exotic)-breed herds, were found to be independently associated with increased herd seroprevalence (OR=5.2, 95% confidence interval 1.4–18.7) in the multiple logistic model with the herd infection status as the dependent variable. The importance of this variable was supported by the multiple betabinomial regression model (OR=3.3, 1.4–7.6) with animal-level prevalence within herd as the outcome variable. Both models also revealed the presence of a negative association between seropositivity and cattle stocking density.     

A field study on the anthelmintic resistance of Parascaris spp. in Arab foals in the Riyadh region,Saudi Arabia

Background: In the last decade, Parascaris spp. resistance to anthelmintics has been recorded in many countries. In Saudi Arabia, there are limited data available on Parascaris spp. resistance to anthelmintics.

Objective: To determine the current status of ivermectin, abamectin and praziquantel combined, and fenbendazole resistance to Parascaris spp. in horses in Saudi Arabia.

Methods: Three hundred and forty-one foals from eleven different farms were examined by faecal egg count (FEC). The foals were all Arab horses aged 17.2 ± 4.5 (SD) months. Ivermectin (n = 46 foals), abamectin and praziquantel combined (n = 46), and fenbendazole (n = 46) were administered on day 0 and faeces were collected on day 14. The study comprised 41 untreated foals as controls. Animals that have FEC of ≥100 eggs per gram (EPG) were used to measure anthelmintic efficacy. Parascaris spp. populations were considered susceptible when faecal egg count reduction (FECR) was ≥95% associated with a lower 95% confidence limit (LCL) >90%, suspected resistant when FECR ≤90% or LCL <90% and resistant when FECR <90% and LCL <90%.

Results: Prevalence of Parascaris spp. infection was 53% (179/341 horses). Anthelmintic resistance to Parascaris spp. were highest following fenbendazole (55% of farms and 65% of foals) and to a lower extent following ivermectin or the combination of abamectin and praziquantel which comprised 27% of farms (and 46% of foals) and 18% of farms (and 10% of foals), respectively.

Conclusion: These data indicate that anthelmintics-resistant Parascaris spp. populations are present on horse farms in Saudi Arabia.     

苜蓿组织培养研究进展

苜蓿Medicago spp.组织培养已在多个种上取得成功,且以紫花苜蓿M. sativa最多。对苜蓿组织培养的外植体选择、培养基组成成分、愈伤组织和体细胞胚的诱导、植株再生以及基因型的选择5个方面阐述了苜蓿组织培养的研究现状。并进一步对目前存在的问题和发展趋势进行了归纳,以期为苜蓿基因工程和细胞工程研究提供有益的借鉴。