Investigations on the efficacy of routinely used phenotypic methods compared to genotypic approaches for the identification of staphylococcal species isolated from companion animals in Irish veterinary hospitals

Background

Identification of Staphylococci to species level in veterinary microbiology is important to inform therapeutic intervention and management. We report on the efficacy of three routinely used commercial phenotypic methods for staphylococcal species identification, namely API Staph 32 (bioMérieux), RapID (Remel) and Staph-Zym (Rosco Diagnostica) compared to genotyping as a reference method to identify 52 staphylococcal clinical isolates (23 coagulase positive; 29 coagulase negative) from companion animals in Irish veterinary hospitals.

Results

Genotyping of a 412 bp fragment of the staphylococcal tuf gene and coagulase testing were carried out on all 52 veterinary samples along with 7 reference strains. In addition, genotyping of the staphylococcal rpoB gene, as well as PCR-RFLP of the pta gene, were performed to definitively identify members of the Staphylococcus intermedius group (SIG). The API Staph 32 correctly identified all S. aureus isolates (11/11), 83% (10/12) of the SIG species, and 66% (19/29) of the coagulase negative species. RapID and Staph-Zym correctly identified 61% (14/23) and 0% (0/23) respectively of the coagulase-positives, and 10% (3/29) and 3% (1/29) respectively of the coagulase-negative species.

Conclusions

Commercially available phenotypic species identification tests are inadequate for the correct identification of both coagulase negative and coagulase positive staphylococcal species from companion animals. Genotyping using the tuf gene sequence is superior to phenotyping for identification of staphylococcal species of animal origin. However, use of PCR-RFLP of pta gene or rpoB sequencing is recommended as a confirmatory method for discriminating between SIG isolates.     

放牧季节及放牧强度对高寒草地植物多样性的影响

在海北高寒草地进行了7年轻度放牧、中度放牧和重度放牧试验,并用围栏控制放牧进行对照.试验显示,物种丰富度和均匀度在夏季牧场和冬季牧场出现不同的变化.在夏季牧场,物种丰富度随着放牧强度的增强而增强,而均匀度则随着放牧强度的增强而下降;在冬季牧场,物种丰富度和放牧之间呈现驼峰反应模式,说明植物的丰富度在中度放牧强度时达到最大.不同牧场生物多样性变化的模式说明夏季牧场放牧强度不足.     

贵阳市高尔夫俱乐部草坪基地建植与管理

通过贵阳市高尔夫球场草皮基地的建植和养护管理 ,从中总结了过渡气候带建植草坪应注意的一些问题。根据所建草坪的功能 ,选择相适应的草种应用于高尔夫球场。并对其适应性进行了研究     

干草原牧草贮藏碳水化合物含量变化规律的研究

１９９３年在内蒙古正蓝旗于草原对１０种牧草贮藏碳水化合物含量的变化规律进行了研究。在植物生长期内，每１５天采样一次，分析牧草茎基部和根部的总糖和还原糖含量。试验结果表明，牧草在返青时都要消耗贮藏碳水化合物，分蘖后开始积累贮藏碳水化合物，在拔节和抽穗时又要消耗贮藏碳水化合物，开花、结实后又积累贮藏碳水化合物。但有的牧草出现相反的情况。根据牧草贮藏碳水化合物含量变化的规律，作者对合理利用草地提出了一些意见和建议。     

化隆县草地鼠虫危害调查

１９９７￣１９９８年对化隆县草场上发生的鼠虫危害进行了调查研究,发现５大类草场都有害鼠和蝗虫分布,其中,在山地草甸和山地草原上较多,全县鼠害草场面积２２５０６ｈｍ＾２,虫害草场面积２１．９８６ｈｍ＾２,高原鼢鼠和高原鼠兔是优势害鼠,狭翅雏蝗和红翅皱膝蝗是优势害虫。高原鼠兔密度为２．５只／ｈｍ＾２。高原鼢鼠为３只／ｈｍ＾２;蝗虫平均密度为２１头／ｈｍ＾２。     

A morphological analysis of the skull size and shape of Kerivoulinae (Chiroptera: Vespertilionidae) from Vietnam

Southeast Asia is a region of high biodiversity, containing species of plants and animals that are yet to be discovered. In this region, bats of the subfamily Kerivoulinae are widespread and diverse with six species recorded in Vietnam. However, the taxonomy of the Kerivoulinae in Asia is complicated. In our study, we used diagnostic characters and multivariate analysis to determine morphological differences between the genera Kerivoula and Phoniscus. We showed that the two genera are distinguishable by the size of second upper incisors, the shape of skull, nasal sinus, canines, second upper and lower premolars. In addition, the two genera can be osteometrically separated by measurements of the braincase height, interorbital width and shape of anterior palatal emargination. Our data clearly revealed the morphological variations in the skull shape of Kerivoula hardwickii in Vietnam. This suggests a possible separation into three morphotypes, representing cryptic species supported by statistical differences with wide variation in skull shape, size and teeth. These results demonstrated Kerivoula hardwickii can be separated three subspecies, and the result will serve as the basis for the future assessment and classification of this group in Southeast Asia.     

线粒体与种子老化的关系

种子作为最基本的生产资料,其活力高低直接关系到农业生产的成败。关于种子老化机理的研究是种子科学研究的热点和难点。线粒体是真核生物细胞内重要的细胞器,是细胞能量合成和物质代谢的中心,也是活性氧产生的主要位点,且普遍认为,活性氧是导致种子老化的主要因素。种子老化过程中线粒体的典型结构逐渐被破坏,呼吸速率和氧化磷酸化效率降低,抗氧化功能发生改变,因此,本文主要概述种子的老化与线粒体结构、呼吸作用、抗氧化系统变化的关系,并阐述线粒体与细胞程序性死亡关系的研究进展,系统分析种子老化与线粒体变化研究中存在的问题及未来发展趋势,以期为研究种子老化的线粒体作用机理提供理论基础。     

利用链烷烃测定放牧羊驼采食量及种类的研究

放牧动物的采食量及摄入牧草的种类,对于评定放牧动物的营养状况有着十分重要的意义。本文采用测定牧草和粪便中链烷烃含量的方法,以羊驼为试验动物,在意大利中部佩鲁贾附近的农场,测定了羊驼的采食量、牧草摄入种类。结果表明:利用链烷烃技术测定放牧动物的采食量和牧草的种类,具有较好的应用价值。     

放牧强度对克氏针茅草原植物功能群的影响

植物功能群及其多样性是维持群落结构复杂性和稳定性的基础,一定程度上反映着草地生态系统的健康状况。本研究以内蒙古呼伦贝尔草原的克鲁伦河流域草原为研究对象,以植物生活型划分功能群类型,比较了3种放牧强度对植物功能群的组成结构、地上生物量和优势度的影响。结果表明,1)轻牧、中牧和重牧3种放牧条件下的总物种数分别为20、23和18种,符合"中度干扰假说";3种放牧强度下多年生非禾草物种数在群落中均占较高比例。2)轻度放牧条件下物种丰富度较低,但各放牧强度下功能群多样性无显著差异(P0.05),物种丰富度与功能群多样性无显著关系。3)随着放牧强度的增加,多年生禾草和灌木、半灌木在群落中的优势地位呈现下降趋势,与之相反,多年生非禾草优势地位越来越显著。重度放牧增加了一、二年生草本在群落中的物种数和地上生物量,但与轻牧、中牧相比,其优势度无显著变化(P0.05)。     

五台山高山、亚高山草甸植物种分布的环境梯度分析和种组划分

通过野外植被调查,结合景观尺度生境因子的测定与模拟,运用CCA排序分析研究区内高山、亚高山草甸地段植物物种分布与环境因子之间的定量关系,综合TWINSPAN分类结果对五台山高寒草甸植物种进行了生态种组划分。结果表明：1)五台山的高山、亚高山草甸分布地段,温度和太阳辐射是控制着草甸植物种分布的关键因子;2)依据草甸物种在CCA排序图上的分布位置,划分出高山冷干型、高山冷湿型、亚高山典型种、亚高山凉干型、亚高山凉湿型、山地暖干型和山地暖湿型几类物种,可以较好地指示研究区的生境特征;3)TWINSPAN划分结果与CCA 划分的生态种组比较吻合。