Development of a method for detecting Coxiella burnetii in cheese samples

Coxiella burnetii is the causative agent of Q fever, and the main route of infection in humans is inhalation of contaminated aerosols. Although oral transmission by contaminated raw milk or dairy products is also a possible route of human infection, there have been few studies investigating the presence of C. burnetii in dairy products. We developed a new method of extracting DNA from cheese and detecting C. burnetii DNA in cheese samples with a nested PCR assay. The limit of detection was 6.0 × 10(2) C. burnetii particles per gram. We subsequently used this method to examine the presence of C. burnetii in cheese at commercial markets in Tokyo from June 2005 to December 2008. Twenty-eight of 147 cheese samples were found to be positive for C. burnetii DNA. However, when we assessed the viability of C. burnetii by inoculating mice with DNA-positive samples, all of the samples were found to be negative. Thus, the viability of C. burnetii appears to have been lost in these cheese samples.     

芜湖市2006年生态足迹分析

采用生态足迹模型,对芜湖市2006年的生态足迹进行计算和分析,评价了芜湖市可持续发展的状况。结果表明：芜湖市人均生态足迹为2．203hm^2,人均生态承载力为0．277hm^2,人均生态赤字为1．926hm^2,万元GDP的生态足迹需求为1．051hm^2,远远低于全国平均水平。反映出芜湖市生态系统处于人类的过度开发利用状态。最后提出了减缓芜湖市生态赤字的对策。     

鸡胚成纤维细胞酵母双杂交cDNA文库的构建及鉴定

选取对新城疫病毒(NDV)易感的鸡胚成纤维细胞(CEF),Trizol提取细胞总RNA,用SMART技术合成双链cDNA,然后利用同源重组的方法在酵母细胞内构建CEF的cDNA文库,以寻找与NDV基质(M)蛋白相互作用的宿主细胞蛋白,探讨其相互作用对NDV装配和出芽的影响.结果表明:提取的细胞总RNA的D260nm/D...     

Molecular typing and antimicrobial resistance of Salmonella enterica subspecies enterica serovar Choleraesuis isolates from diseased pigs in Japan

Salmonella enterica serovar Choleraesuis (S. Choleraesuis) isolates derived from diseased pigs in Japan during 2001 and 2005 were analyzed for biotype, based on H(2)S production and dulcitol fermentation, pulsed-field gel electrophoresis (PFGE) profile, and antimicrobial resistance profile. S. Choleraesuis biotype Choleraesuis (biotype Choleraesuis) was classified into one genotype, while varietas Kunzendorf (var. Kunzendorf) was classified into two genotypes. The isolates of var. Kunzendorf belonging to one genotype were isolated in a limited area of Japan. Variation in the antimicrobial resistance pattern was observed in isolates of both biotypes Choleraesuis and var. Kunzendorf. We have also shown that the PFGE profile was associated with the biotype and isolation region of each isolate.     

Water penetration into rice grains during soaking observed by gradient echo magnetic resonance imaging

The water penetration into a rice grain during soaking was monitored by three-dimensional gradient echo magnetic resonance imaging, which has the advantage of a short measurement time and a sufficient sensitivity for low-moisture samples. The water penetration route was compared between the milled and brown rice grains of two japonica cultivars. In normal milled rice grains of Koshihikari, water first penetrated the ventral side surface and the embryo attachment site of the endosperm, then migrated along the central line and transverse cracks, and finally diffused to all parts of the endosperm. In milled rice grains of Yamadanishiki with a white core, water quickly infiltrated into the cracks or chalky parts on the dorsiventral line and then diffused to the lateral side. In brown rice grains of both cultivars water penetrated extremely slowly and did not infiltrate directly into transverse cracks or the white core due to inhibition by the pericarp and seed coat. The central part of every grain allowed more water to penetrate. The route, pattern and speed of water penetration were determined by the morphological structure, crack formation and hardness distribution associated with the packing of the starch granules in the grain.     

西红花真菌性病害与生防菌鉴定研究进展

西红花Crocus sativus为多年生草本植物,具有活血化瘀、凉血解毒、抗癌、抗氧化等多种药用价值。由于无性繁殖及连作障碍,西红花病害日益严重;以真菌性引起的西红花球茎腐烂病害最为常见,造成西红花产量锐减,严重影响产业发展。解决真菌性病害是提高西红花产量与品质的有效途径之一。围绕西红花土壤真菌性病害、西红花内生真菌、西红花真菌病害生防菌的分离与鉴定研究进展等展开综述,分析西红花研究前景。后续研究可以从3个方向展开,一是基于现代宏基因组测序技术挖掘西红花球茎腐烂致病菌和拮抗菌,二是基于合成生物学和发酵工程技术方法实现西红花药效物质的异源高效生物合成,三是创制西红花脱毒新种质,为生产提供可靠的优质种源。本研究能为西红花真菌性病害防治、生物菌肥的开发利用等研究提供参考。表3参89     

文山牛母牛生长发育规律分析

为了解文山牛母牛的体重和体尺性状的生长发育规律,加强文山牛母牛品种选育,进一步提高生产性能,本研究以91头文山牛母牛为试验对象,分别测定0、6、12、18、24和36月龄的体重和体尺指标进行相关性分析和回归分析,从而建立相应的最优回归方程。结果表明：文山牛母牛体重、体高、十字部高、体斜长、胸围、腹围、管围的累计生长量是随着月龄的增长而增加,绝对生长量和相对生长量则是随着月龄的增长而降低,说明文山牛母牛体重和体尺在随着月龄增长而增长,但是其生长强度和速度均在不断下降,表现为早期生长速度较快,后期生长速度缓慢,且在6月龄时达到生长高峰期,分别增长了77.95 kg、25.22 cm、25.68 cm、32.34 cm、40.10 cm、49.71 cm、2.62 cm。在不同生长发育阶段体重的变异系数均最大(9.88%、17.25%、18.04%、19.05%、18.50%、16.43%);除出生阶段外,其次为腹围(15.19%、12.82%、12.79%、12.04%、10.37%)。出生阶段的体斜长和管围相关性不显著(P>0.05),其余各生长阶段各指标间相关性均极显著(P<...     

Expansion of dwarf bamboo, Sasa nipponica, grassland under feeding pressure of sika deer, Cervus nippon, on subalpine coniferous forest in central Japan

The long-term changes of the area of Sasa nipponica grassland, bark stripping damage to trees by sika deer, Cervus nippon, and sika deer densities on Mt. Ohdaigahara were assessed with aerial photographs, information from previous studies, and field experiments. The grasslands expanded year after year. The expansion rate was highest from 1982 to 1992, and lowest from 1992 to 1997. Bark-stripping damage on coniferous trees was heavier than that on broadleaf trees in both the early 1980s and 1998. The deer density in the eastern part of the area had been high (14.4–64.3 km⁻²) from 1984 until 1998. We presume that rich growth of S. nipponica and heavy feeding pressure by sika deer over the long term caused expansion of S. nipponica grasslands by killing canopy trees by bark stripping and preventing forest regeneration.     

National surveillance of Salmonella enterica in food-producing animals in Japan

A total of 518 fecal samples collected from 183 apparently healthy cattle, 180 pigs and 155 broilers throughout Japan in 1999 were examined to determine the prevalence and antimicrobial susceptibility of Salmonella. The isolation rates were 36.1% in broilers, 2.8% in pigs and 0.5% in cattle. S. enterica Infantis was the most frequent isolate, found in 22.6% of broiler fecal samples. Higher resistance rates were observed against oxytetracycline (82.0%), dihydrostreptomycin (77.9%), kanamycin (41.0%) and trimethoprim (35.2%). Resistance rates to ampicillin, ceftiofur, bicozamycin, chloramphenicol and nalidixic acid were <10%. CTX-M-2 β-lactamase producing S. enterica Senftenberg was found in the isolates obtained from one broiler fecal sample. This is the first report of cephalosporin-resistant Salmonella directly isolated from food animal in Japan.