食源性致病菌快速检测技术研究进展

食源性致病菌是影响食品安全的主要因素之一,传统的细菌分离、培养与鉴定由于需时较长,特别是有的细菌难以培养,难以适应食源性疾病预防控制的需要,因而快速、简便、特异的检测方法成为研究的热点。对电阻抗、放射测量、微热量、ELISA、PCR、基因芯片和生物传感器技术在金黄色葡萄球菌、沙门菌、肠出血性大肠埃希菌等食源性致病菌快速检测中的应用研究进行综述。     

食源性致病菌多重分子生物学检测技术研究进展

快速、可靠的食源性致病菌高通量检测方法对于确保食品安全具有重要意义,近年基于DNA水平的多重分子生物学检测技术迅速发展,针对各种不同的食源性致病菌建立了多种多重分子检测技术,包括多重PCR、多重实时荧光PCR以及基因芯片等。对这些多重分子检测技术的最新研究进展作一综述,并且建议在今后该技术的研究中,仍需要在食品中多种致病菌同时选择性增菌培养、亚致死损伤修复以及检测内标的构建等方面取得突破,从而能够更好地实现食源性致病菌的高通量检测。     

生物传感器在食源性致病菌检测中应用的研究进展

食源性致病菌作为引起食源性疾病的主要因素,受到人们的高度重视,发展简便、快速、高灵敏度和低成本的食源性致病菌检测方法对降低食源性疾病发病率具有重要意义。生物传感器技术是一种由多学科交叉渗透发展形成的全新微量分析技术,具有灵敏度高、分析速度快等特点,被广泛应用于食源性致病菌的检测。文中介绍了生物传感器的基本原理,综述了常见的生物传感器在食源性致病菌检测中的应用,并对其发展趋势进行了展望。     

食源性致病菌检测免疫传感器研究进展

食源性致病菌是造成食品安全事件的主要原因之一,因此其检测方法已成为人们研究的热点.食源性致病菌的检测方法主要有病原体培养法、免疫学方法、核酸检测和生物传感器等.其中,免疫传感器基于抗原抗体特异性结合,整合光学、电化学等多学科交叉技术,具有特异性强、检测速度快等特点.本文对比食源性致病菌传统检测方法,综述了近年来免疫传感...     

PCR技术检测食源性致病菌的研究进展

食源性致病菌的检测技术是食源性疾病预防与控制的关键环节。PCR是近年来广泛应用于食源性致病菌快速检测的方法之一。在食源性致病菌中,用于PCR检测的靶基因包括各种毒力基因、酶基因及特异性鉴别基因。这些靶基因的发现推动了食源性致病菌PCR快速检测的发展。     

质谱法检测食源性致病菌技术研究进展

食源性致病菌存在广泛,能够引起人类的疾病甚至死亡,研究发现超过一半的食品安全问题来源于食源性致病菌的污染。如何快速有效地检测出食源性致病菌是预防和控制食品安全问题的关键环节。系统地介绍了检测食源性致病菌的方法,包括传统培养法、代谢学法、分子生物学法、免疫学方法等传统方法以及新兴的质谱法。质谱法有检测效率高、操作简便、灵敏度高等优点,着重对质谱法的原理、应用以及未来的发展趋势进行了阐述,以期为该技术的研究开发和推广应用提供参考。     

生态代谢组学研究进展

代谢组学指某一生物系统中产生的或已存在的代谢物组的研究,以质谱和核磁共振技术为分析平台,以信息建模与系统整合为目标。随着代谢组学中的研究方法与技术成为生态学研究的有力工具,生态代谢组学概念应运而生,即研究某一个生物体对环境变化的代谢物组水平的响应。理清代谢组学与生态代谢组学学科发展的脉络,综述代谢组学研究中的常用技术及其优势与局限性,论述代谢组学技术在生态学研究中的应用现状,展望代谢组学技术与其他系统生物学组学技术的结合在生态学中的应用前景,提出生态代谢组学研究者未来要完成的任务和面对的挑战。     

果树代谢组学研究进展

果树代谢组学是继基因组学、蛋白质组学之后又一新兴的组学技术,主要是从代谢水平研究果树整体或局部代谢物变化差异,帮助发现新功能基因和了解代谢网络。目前果树代谢组学研究刚刚起步,相关研究相对较少,该文介绍了果树代谢组学的主要研究内容与方法以及在果树上的相关应用。     

乳酸菌代谢组学研究进展

代谢组学作为系统生物学的重要分支,近年来在微生物研究领域受到广泛关注,并取得了重要进展。目前乳酸菌代谢组学正日益成为研究的热点,就乳酸菌代谢组学研究中有关样品的制备、分析鉴定和数据分析等涉及的主要方法进行概述,并介绍一些乳酸菌代谢组学应用的典型实例,对乳酸菌代谢组学研究中潜在的问题和未来发展趋势进行讨论。     

食源性致病菌群体感应信号分子的检测

群体感应(Quorum sensing,QS)在食物中毒导致的食源性疾病暴发机制和食物腐败变质中起主要作用,QS影响致病菌的细胞被膜形成和致病性。文中通过深入了解食源性致病菌的QS信号分子,综述了革兰氏阴性和革兰氏阳性菌产生的信号分子类型,同时介绍了检测QS信号分子的不同技术,并根据QS机制在食品中的影响提出了思考和建议,为监控食源性致病菌提供依据。     

饮用水中5种致病菌多重PCR技术检测研究

沙门氏菌(Salmonella sp．)、志贺氏菌(Shigella sp．)、绿脓杆菌(Pseudonmnas aeruginosa)、肠出血型大肠杆菌O157(Eterohaemorrhagic O157)和副溶血弧菌(Vibrio rahaemolyticus)是5种饮用水中不得检出食源性致病菌,根据它们的毒素基因、高度保守基因及特异性基因,设计合成5对寡核苷酸引物,应用PCR技术对10个属的30株细菌进行引物特异性检测。通过对多重PCR反应体系、条件进行优化,显提高了检测灵敏度。初步应用于水样分析中,极大的缩短了检测时间、降低了成本。实验结果表明：5对寡核苷酸引物都具较高的特异性和专一性,多重PCR检测灵敏度达到10^1～10^2cfu,检测需5～6h,在水样检测的初步应用中得到了均一、稳定、清晰的结果,可推广应用于环境监测、水源检测、食品卫生监督、商品检验检疫等领域。     

凝集素在食源致病菌快速检测中应用的研究进展

凝集素是一类具有独特糖专一性、能够与糖非共价可逆结合的蛋白质。食源致病菌表面存在大量糖蛋白分子,凝集素因能够与其发生高亲和力的结合,被广泛应用于食源致病菌的快速检测中。凝集素作为识别分子用于食源致病菌的分离与检测,能够改善检测新方法的实用性、消除食品基质的干扰、缩短样品的处理时间、提高检测的灵敏度。本文介绍了凝集素的基本信息及其糖特异性识别机制,并对凝集素在食源致病菌快速检测领域的应用进展进行了综述。     

HORA suite: a database and software for human metabolomics

HORA suite (Human blOod Range vAlidator) consists of a Java application used to validate the metabolomic analysis of human blood against a database that stores the normal plasma and serum range concentrations of metabolites. The goal of HORA is to find the metabolites that are outside the normal range and to show those not present in the list provided by the user, for different thresholds of concentration. Moreover it supplies a graphical interface to manage the data. The software can also be used to compare different metabolomic techniques. HORA is open-source software and it can be accessed at . A separate file contains instructions for the installation and a brief tutorial.     

食源性变形杆菌簇致病菌的检测

为建立食源性变形杆菌簇致病菌的检测方法,对富集培养基、选择性平板分离培养基和生化特性进行了筛选比较。结果表明,肠杆菌富集肉汤培养基更有利于变形杆菌簇致病菌的检出,平板分离培养基可用EMB琼脂培养基和SS琼脂培养基(或麦康凯琼脂培养基),初筛方法为革兰氏反应和苯丙氨酸脱氨酶实验,最后用其他生化反应进行确认。该方法检出率高,检测范围较宽,可为建立变形杆菌簇致病菌的检验标准提供实验依据。     

Development and application of an oligonucleotide microarray for the detection of food-borne bacterial pathogens

The rapid and accurate detection and identification of food-borne pathogenic bacteria is critical for food safety. In this paper, we describe a rapid (<4 h) high-throughput detection and identification system that uses universal polymerase chain reaction (PCR) primers to amplify a variable region of bacterial the 16S rRNA gene, followed by reverse hybridization of the products to species-specific oligonucleotide probes on a chip. This procedure was successful in discriminating 204 strains of bacteria from pure culture belonging to 13 genera of bacteria. When this method was applied directly to 115 strains of bacteria isolated from foods, 112/115 (97.4%) were correctly identified; two strains were indistinguishable due to weak signal, while one failed to produce a PCR product. The array was used to detect and successfully identify two strains of bacteria from food poisoning outbreak samples, giving results through hybridization that were identical to those obtained by traditional methods. The sensitivity of the microarray assay was 10² CFU of bacteria. Thus, the oligonucleotide microarray is a powerful tool for the detection and identification of pathogens from foods. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

微生物鉴定系统在肠道病原菌检测中的应用

目的建立简便、快速、系统的病原菌生化检测方法。方法通过应用ATB微生物鉴定系统对112株可疑肠道病原菌菌株进行检测分析,并与国家标准法结合鉴定。结果ATB微生物鉴定系统在112株可疑肠道病原菌菌株中检测出肠道病原菌66株,鉴定结果与国家标准法结果一致,而对常规检测不能确定的37菌株也能给出明确的鉴定结果。结论该系统操作简便、快速,缩短了鉴定周期,提高了鉴定效率,检测范围广,可以作为肠道致病菌检测常规方法的辅助工具,有利于病原菌的快速检出。     

Urinary Biomarkers of Brain Diseases

Biomarkers are the measurable changes associated with a physiological or pathophysiological process. Unlike blood, urine is not subject to homeostatic mechanisms. Therefore, greater fluctuations could occur in urine than in blood, better reflecting the changes in human body. The roadmap of urine biomarker era was proposed. Although urine analysis has been attempted for clinical diagnosis, and urine has been monitored during the progression of many diseases, particularly urinary system diseases, whether urine can reflect brain disease status remains uncertain. As some biomarkers of brain diseases can be detected in the body fluids such as cerebrospinal fluid and blood,there is a possibility that urine also contain biomarkers of brain diseases. This review summarizes the clues of brain diseases reflected in the urine proteome and metabolome.     

Exhaled volatile organic compounds for phenotyping chronic obstructive pulmonary disease: a cross-sectional study

Background

Non-invasive phenotyping of chronic respiratory diseases would be highly beneficial in the personalised medicine of the future. Volatile organic compounds can be measured in the exhaled breath and may be produced or altered by disease processes. We investigated whether distinct patterns of these compounds were present in chronic obstructive pulmonary disease (COPD) and clinically relevant disease phenotypes.

Methods

Breath samples from 39 COPD subjects and 32 healthy controls were collected and analysed using gas chromatography time-of-flight mass spectrometry. Subjects with COPD also underwent sputum induction. Discriminatory compounds were identified by univariate logistic regression followed by multivariate analysis: 1. principal component analysis; 2. multivariate logistic regression; 3. receiver operating characteristic (ROC) analysis.

Results

Comparing COPD versus healthy controls, principal component analysis clustered the 20 best-discriminating compounds into four components explaining 71% of the variance. Multivariate logistic regression constructed an optimised model using two components with an accuracy of 69%. The model had 85% sensitivity, 50% specificity and ROC area under the curve of 0.74. Analysis of COPD subgroups showed the method could classify COPD subjects with far greater accuracy. Models were constructed which classified subjects with ≥2% sputum eosinophilia with ROC area under the curve of 0.94 and those having frequent exacerbations 0.95. Potential biomarkers correlated to clinical variables were identified in each subgroup.

Conclusion

The exhaled breath volatile organic compound profile discriminated between COPD and healthy controls and identified clinically relevant COPD subgroups. If these findings are validated in prospective cohorts, they may have diagnostic and management value in this disease.     

A top-down proteomics approach for differentiating thermal resistant strains of Enterobacter sakazakii

Thermal tolerance has been identified as an important factor relevant to the pathogenicity of Enterobacter sakazakii in human neonates. To identify a biomarker specific for this phenotypic trait, intact protein expression profiles of 12 strains of E. sakazakii were obtained using liquid chromatography mass spectrometry. Proteins were extracted from the bacterial cells, separated by reversed-phase liquid chromatography and mass analyzed. At the end of the chromatography run, the uncharged masses of the multiply charged proteins were determined via automated software routines. The resulting data provided an accurate mass expression profile of the proteins found in the individual strains. From the individual expression profiles, it was possible to identify unique proteins corresponding to strains with thermal resistance. One protein found only in the thermal tolerant strains was sequenced and identified as homologous to a hypothetical protein found in the thermal tolerant bacteria, Methylobacillus flagellatus KT. The protein sequence of this protein was then used to reverse-engineer PCR primers for the gene sequence associated with the protein. In all cases, only thermal tolerant strains of E. sakazakii produced amplified PCR products, demonstrating the specificity of this biomarker.