Rapid O serogroup identification of the ten most clinically relevant STECs by Luminex microbead-based suspension array

Identification and serotyping of Shiga toxin-producing Escherichia coli during foodborne outbreaks can aid in matching clinical, food, and environmental isolates when trying to identify the source of illness and ultimately food contamination. Herein we describe a Luminex microbead-based suspension array to identify the O serogroup of the ten most clinically relevant STECs: O26, O45, O91, O103, O111, O113, O121, O128, O145, and O157. The use of PCR followed by Luminex xMAP® technology enables the detection of multiple analytes in a single multiplex reaction with high throughput capabilities. One hundred and fourteen STEC isolates were correctly identified with no false positives among forty-six other organisms using this assay. Assay performance was tested in multiple laboratories using a panel of eleven different STEC serogroups on the Bio-Plex 200 and MAGPIX instruments. The STEC microbead-based suspension array can be performed in a 96-well plate format for high throughput screening in less than 4 h. Furthermore, it is expandable, allowing for the addition of O serogroups should the need arise.     

Use of Pyromark Q96 ID pyrosequencing system in identifying bacterial pathogen directly with urine specimens for diagnosis of urinary tract infections

Detection and identification of bacterial etiology in urine is critical for accurate diagnosis and subsequent rational treatment of urinary tract infections (UTIs). Urine culture followed by a series of biochemical reactions is currently the standard method for detecting and distinguishing microorganisms associated with UTIs. The whole procedure commonly takes more than 24 h. Here we developed a new system combining 16S rRNA gene broad-range PCR with pyrosequencing technology that allows for bacteria detection and identification in urine in 5 h. To evaluate this system for rapid diagnosis of bacteriuria, 768 urine specimens were collected from patients with suspected UTIs and were tested side-by-side using standard urine culture-based identification method and the pyrosequencing method. The results from pyrosequencing correlated well with those from traditional culture-based identification method. The overall agreement between these two methods reached 98.0% (753/768). In addition, we tested the sensitivity of pyrosequencing method and determined that urine bacterial numbers as low as 10⁴ cfu/ml could be accurately detected and identified. In conclusion, compared with traditional biochemical method, the PCR-pyrosequencing system significantly improved the detection and identification of bacteriuria with shorter time, higher accuracy, and higher throughput, thus allowing earlier pathogen-adapted antibiotic therapy for patients.     

发冠卷尾性别判定的初步研究

摘要：发冠卷尾（Dicrurus hottentottus）由于被认为是雌雄同态而在野外难以鉴别性别。我们研究了河南董寨国家级自然保护区79只已用分子生物学方法鉴定出性别的发冠卷尾（D.h.brevirostris）在形态量度上的性别差异,并据此构建了判别式方程,用于鉴定其性别。所考察的体征包括体重、喙长、喙粗、头喙长...     

Mating strategies in primates: a game theoretical approach to infanticide

Infanticide by newly immigrated or newly dominant males is reported among a variety of taxa, such as birds, rodents, carnivores and primates. Here we present a game theoretical model to explain the presence and prevalence of infanticide in primate groups. We have formulated a three-player game involving two males and one female and show that the strategies of infanticide on the males' part and polyandrous mating on the females' part emerge as Nash equilibria that are stable under certain conditions. Moreover, we have identified all the Nash equilibria of the game and arranged them in a novel hierarchical scheme. Only in the subspace spanned by the males are the Nash equilibria found to be strict, and hence evolutionarily stable. We have therefore proposed a selection mechanism informed by adaptive dynamics to permit the females to transition to, and remain in, optimal equilibria after successive generations. Our model concludes that polyandrous mating by females is an optimal strategy for the females that minimizes infanticide and that infanticide confers advantage to the males only in certain regions of parameter space. We have shown that infanticide occurs during turbulent changes accompanying male immigration into the group. For changes in the dominance hierarchy within the group, we have shown that infanticide occurs only in primate groups where the chance for the killer to sire the next infant is high. These conclusions are confirmed by observations in the wild. This model thus has enabled us to pinpoint the fundamental processes behind the reproductive decisions of the players involved, which was not possible using earlier theoretical studies.     

Integrating motion-detection cameras and hair snags for wolverine identification

We developed an integrated system for photographing a wolverine's (Gulo gulo) ventral pattern while concurrently collecting hair for microsatellite DNA genotyping. Our objectives were to 1) test the system on a wild population of wolverines using an array of camera and hair-snag (C&H) stations in forested habitat where wolverines were known to occur, 2) validate our ability to determine identity (ID) and sex from photographs by comparing photographic data with that from DNA, and 3) encourage researchers and managers to test the system in different wolverine populations and habitats and improve the system design. Of the 18 individuals (10 M, 8 F) for which we obtained genotypes over the 2 years of our study, there was a 100% match between photographs and DNA for both ID and sex. The integrated system made it possible to reduce cost of DNA analysis by >74%. Integrating motion-detection cameras and hair snags provides a cost-effective technique for wildlife managers to monitor wolverine populations in remote habitats and obtain information on important population parameters such as density, survival, productivity, and effective population size. © 2011 The Wildlife Society.     

Applications of whole-cell matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry in systematic microbiology

In the last few years matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been increasingly studied and applied for the identification and typing of microorganisms. Very recently, MALDI-TOF MS has been introduced in clinical routine microbiological diagnostics with marked success, which is remarkable considering that not long ago the technology was generally seen as being far from practical application. The identification of microbial isolates by whole-cell mass spectrometry (WC-MS) is being recognized as one of the latest tools forging a revolution in microbial diagnostics, with the potential of bringing to an end many of the time-consuming and man-power-intensive identification procedures that have been used for decades. Apart from applications of WC-MS in clinical diagnostics, other fields of microbiology also have adopted the technology with success. In this article, an over-view of the principles of MALDI-TOF MS and WC-MS is presented, highlighting the characteristics of the technology that allow its utilization for systematic microbiology.     

全缘凤尾蕨化学成分的研究

全缘凤尾蕨资源丰富且在贵州分布广泛,具有清热利湿、活血消肿的功效。为了探明该植物的物质基础、寻找相关的活性成分和先导化合物,该文用95%甲醇对全缘凤尾蕨地上部分浸渍提取,采用硅胶、MCI gel CHP 20P、YMC gel ODS-A-HG、Sephadex LH-20等色谱技术对全缘凤尾蕨的化学成分进行分离纯化,根据波谱数据鉴定化合物的结构。结果表明:从全缘凤尾蕨中分离得到18个化合物,分别鉴定为(-)-α-tocospirone(1)、环鸦片甾烯醇(2)、(2S,3S)-pterosin C(3)、(2R,3S)-pterosin C(4)、pterosin B(5)、pterosin F(6)、α-紫罗兰酮A(7)、sauropunol C/D(8/8’)、ficusol(9)、棕榈酸(10)、2-dodec-2-enyl-succinic acid dimethyl ester(11)、methyl-9-phenyl-10-hydroxyoctadecanoate(12)、十六烷酸甘油酯(13)、methyl elaidate(14)、(Z,Z)-9,12-十八烷二烯酸甲酯(15)、(Z,Z,Z)-9,12,15-十八烷三烯酸甲酯(16)、胡萝卜苷(17)、β-谷甾醇(18)。所有化合物均为首次从该植物中分离得到。该研究结果为合理利用其资源奠定了科学基础。     

Cork stoppers industry: defining appropriate mould colonization

AIMS: The main aims of this work were the study of cork slabs moulds colonization and the evaluation of the moulds diversity during cork processing steps, in different cork stoppers factories. Simultaneously, it was envisaged to perform an evaluation of the air quality. METHODS AND RESULTS: Moulds were isolated and identified from cork slabs and cork samples in four cork stoppers factories. The identification was based on morphological characters and microscopic observation of the reproductive structures. Airborne spore dispersion was assessed using a two stage Andersen sampler. It was observed that Chrysonilia sitophila was always present on cork slabs during the maturing period, but mould diversity appeared to be associated to the different factory configurations and processing steps. CONCLUSIONS: Spatial separation of the different steps of the process, including physical separation of the maturation step, is essential to guarantee high air quality and appropriate cork slabs colonization, i.e. C. sitophila dominance. The sorting and cutting of the edges of cork slabs after boiling and before the maturing step is also recommended. SIGNIFICANCE AND IMPACT OF THE STUDY: This study is very important for the cork stopper industry as it gives clear indications on how to keep high quality manufacturing standards and how to avoid occupational health problems.     

一株鸭源传染性支气管炎病毒的分离鉴定及结构蛋白基因和血清型分析

【目的】对从广西某鸭场发生呼吸道感染的11天龄樱桃谷肉鸭分离到的病毒株进行鉴定,并探索此鸭源病毒分离株的遗传变异情况。【方法】通过血凝试验、鸡胚接种实验、3?端非编码区(3'UTR)基因扩增与序列测定对分离株进行鉴定,并对该分离株的结构基因S1、E、M和N分别进行序列测定以及相似性、系统进化树分析和血清型鉴定。【结果】血凝试验为阴性,接种鸡胚盲传5代后出现侏儒胚,3?UTR基因测序结果表明为传染性支气管炎病毒(IBV)序列。该分离株S蛋白的裂解位点为RRSRR,S1、E、M和N基因与IBV毒株H120、4/91、LTD3核苷酸相似性分别为:78.6%–99.7%、85.4%–100.0%、91.6%–93.2%、86.7%–91.7%。除N基因存在点突变外,S1、E和M基因均存在氨基酸的突变、插入和(或)缺失。系统进化树分析显示,其S1基因属于4/91型,E、M和N基因均为LDT3型。血清型分析表明,该分离株的血清型不同于疫苗株H120和4/91。【结论】此鸭源病毒分离株为IBV,且该分离株的基因型与血清型均发生了变异。本研究结果暗示禽类传染性支气管炎的防控面临着更严峻的挑战。     

葎草雌雄植株开花物候和花器官对干旱的响应差异

摘要：以蓓草（Humulusscandens）为实验材料,在控制土壤水分的条件下探究干旱对雌雄异株植物开花物候和花器官形态的影响,结果表明：干旱胁迫将导致蓰草雌雄种群花期提前．花期持续时间延长,雌花将比雄花提早开放;干旱胁迫下雄花的花序轴长、花序轴直径和花药粒径长均分别显著减小24．81％。29．07％和5．14％（P〈0．001,P=0．003,P=0．024）,花粉活力和花粉含量显著下降：干旱胁迫导致雌花的花序轴长、柱头长度和花序的平均花数量显著增大9．78％,70．62％和57．04％（P=0．039．P〈0．001．P〈0．001）;干旱胁迫下种子粒径长、种子粒径宽、种子单粒重和种子千粒重分别显著下降12．12％、12．59％、43．43％和15．38％（显著度水平均为P〈0．001）;干旱胁迫下雌雄植株的地上部分生物量均显著降低（P=0．002,P=0．020）,且雌株的生殖投入在干旱胁迫下显著高于雄株（P=0．049）。研究结果表明了蓰草雌雄植株开花物候及花器官对干旱的响应明显不同。与雄株相比．雌株在干旱胁迫下增加了生物量向生殖器官的分配,从而最大程度地减轻胁迫对其繁殖能力的影响。