Taqman荧光探针技术在食源性致病菌检测中的应用

Taqman荧光探针技术作为定量PCR的代表性方法,综合了PCR技术及荧光标记技术,由引物和探针双重控制靶基因的选择,具有很好的特异性和灵敏度。近年来该技术逐步应用于食品中致病微生物的检测。本文概述了Taqman荧光探针技术的原理、优缺点及其在食源性致病菌检测中的应用与研究进展,并对其应用前景进行了探讨。      

二重LAMP检测鸡蛋污染致病菌

为快速检测污染鸡蛋的致病菌,实验从鸡蛋蛋体表面得到2株菌X1、X2,结合16S r RNA克隆及质粒测序分子方法对2株菌分类分析,发现2株菌X1和X2分别为:蜡样芽孢杆菌Bacillus cereus NC7401(AP007209)、金黄色葡萄球菌Staphylococcus aureus(AP003088)。针对两种菌的nhe、nuc基因具有较强的保守性,设计2套环介导等温扩增(LAMP)引物。先进行反应体系优化,得到25μL LAMP反应体系最适温度为60℃、最适Mg SO4添加量为1.5μL,引物最适量为2.0μL。再进行二重LAMP鉴定2株污染鸡蛋的致病菌,发现目的菌X1和X2的特异性扩增结果为阳性,其他9株非目的菌扩增结果为阴性,其灵敏度检测限达10 fg/μL。此二重LAMP检测法有快速、特异、灵敏的特点,可快速检测食源性致病菌。      

高光谱成像技术在食品品质无损检测中的应用

高光谱成像技术结合光谱技术和图像技术的优势,能够很好的捕获光谱信息和图像信息。其丰富的光谱信息能够有效的提取样品内部特征。该分析技术已广泛应用于检测食品的水分含量、新鲜度、生物污染等。本文介绍并分析了高光谱成像技术在食品检测中的各种应用,指出了目前高光谱成像技术存在的不足之处,指明了该技术领域工作者今后的重点研究方向,并对高光谱成像技术发展前景进行了分析和展望。      

基于NMR纳米探针的生物传感器用于快速检测沙门氏菌

通过将沙门氏菌单抗与羧基磁珠偶联制备免疫磁珠,并以此为NMR分子探针,以免疫磁珠为生物传感器,特异性地捕获并检测出样品中的致病菌,从而建立一种更快的检测沙门氏菌的方法。实验将得到的不同样品溶液放入核磁共振仪中检测自旋-自旋弛豫时间（T2）值,考察不同条件对T2值的影响。通过实验发现,免疫磁珠的使用量,缓冲溶液的选择,捕获时间的长短都会对样品T2值产生影响。通过优化实验,分别绘制出不同条件下T2值的曲线变化,并得出最佳捕获条件。在捕获缓冲溶液为磷酸盐缓冲溶液PBS（0.01 mol/L,p H7.4）,免疫磁珠使用量为50μg,混匀捕获时间为1.5 h的条件下,核磁共振仪测得的样品T2值曲线最佳。其检测线性范围为10⁴¹0⁷CFU/m L。本研究为沙门氏菌的检测提供了新的方法和途径,缩短了检测时间和工序,并且为低场核磁共振技术研究应用开辟了广阔的空间。      

牛乳过敏原及加工技术对其致敏性的影响

对婴幼儿来说,牛乳营养丰富,是母乳最好的替代品,但牛乳中的蛋白质可能会引起过敏。牛乳中的主要过敏原是酪蛋白、β-乳球蛋白和α-乳白蛋白。本文从牛乳过敏原的结构和抗原表位、热处理、发酵和酶处理等不同的加工技术对牛乳蛋白致敏性的影响和过敏原标记检测方法三个方面进行了综述,为开发低致敏牛乳制品提供借鉴。      

Fluid Biomarkers in HPV and Non-HPV Related Oropharyngeal Carcinomas: From Diagnosis and Monitoring to Prognostication—A Systematic Review

Biomarkers are crucial in oncology, from detection and monitoring to guiding management and predicting treatment outcomes. Histological assessment of tissue biopsies is currently the gold standard for oropharyngeal cancers, but is technically demanding, invasive, and expensive. This systematic review aims to review current markers that are detectable in biofluids, which offer promising non-invasive alternatives in oropharyngeal carcinomas (OPCs). A total of 174 clinical trials from the PubMed search engine in the last 5 years were identified and screened by 4 independent reviewers. From these, 38 eligible clinical trials were found and subsequently reviewed. The biomarkers involved, categorized by human papillomavirus (HPV)-status, were further divided according to molecular and cellular levels. Recent trials investigating biomarkers for both HPV-positive and HPV-negative OPCs have approaches from various levels and different biofluids including plasma, oropharyngeal swabs, and oral rinse. Promising candidates have been found to aid in detection, staging, and predicting prognosis, in addition to well-established factors including HPV-status, drinking and smoking status. These studies also emphasize the possibility of enhancing prediction results and increasing statistical significance by multivariate analyses. Liquid biopsies offer promising assistance in enhancing personalized medicine for cancer treatment, from lowering barriers towards early screening, to facilitating de-escalation of treatment. However, further research is needed, and the combination of liquid biopsies with pre-existing methods, including in vivo imaging and invasive techniques such as neck dissections, could also be explored in future trials.     

Nanotechnology Meets Oncology: A Perspective on the Role of the Personalized Nanoparticle-Protein Corona in the Development of Technologies for Pancreatic Cancer Detection

In recent years nanotechnology has opened exciting opportunities in the struggle against cancer. In 2007 Dawson and coworkers demonstrated that nanomaterials exposed to biological fluids are coated with plasma proteins that form the so-called “protein corona”. A few years later our joint research team made of physicists, chemists, biotechnologists, surgeons, oncologists, and bioinformaticians introduced the concept of “personalized protein corona” and demonstrated that it is unique for each human condition. This concept paved the way for the development of nano-enabled blood (NEB) tests for the diagnosis of pancreatic ductal adenocarcinoma (PDAC). These studies gave an impetus to serious work in the field that came to maturity in the late 2010s. In this special issue, we provide the reader with a comprehensive overview of the most significant discoveries of our research team in the field of PDAC detection. We focus on the main achievements with an emphasis on the fundamental aspects of this arena and how they shaped the integration of different scientific backgrounds towards the development of advanced diagnostic technologies. We conclude the review by outlining future perspectives and opportunities to transform the NEB tests into a reliable clinical diagnostic technology for early diagnosis, follow-up, and management of PDAC patients.     

Intraoperative Tumor Detection Using Pafolacianine

Cancer is a leading cause of death worldwide, with increasing numbers of new cases each year. For the vast majority of cancer patients, surgery is the most effective procedure for the complete removal of the malignant tissue. However, relapse due to the incomplete resection of the tumor occurs very often, as the surgeon must rely primarily on visual and tactile feedback. Intraoperative near-infrared imaging with pafolacianine is a newly developed technology designed for cancer detection during surgery, which has been proven to show excellent results in terms of safety and efficacy. Therefore, pafolacianine was approved by the U.S. Food and Drug Administration (FDA) on 29 November 2021, as an additional approach that can be used to identify malignant lesions and to ensure the total resection of the tumors in ovarian cancer patients. Currently, various studies have demonstrated the positive effects of pafolacianine’s use in a wide variety of other malignancies, with promising results expected in further research. This review focuses on the applications of the FDA-approved pafolacianine for the accurate intraoperative detection of malignant tissues. The cancer-targeting fluorescent ligands can shift the paradigm of surgical oncology by enabling the visualization of cancer lesions that are difficult to detect by inspection or palpation. The enhanced detection and removal of hard-to-detect cancer tissues during surgery will lead to remarkable outcomes for cancer patients and society, specifically by decreasing the cancer relapse rate, increasing the life expectancy and quality of life, and decreasing future rates of hospitalization, interventions, and costs.     

Rapid Detection of Fusarium oxysporum Using Insulated Isothermal PCR and a Rapid,Simple DNA Preparation Protocol

We developed an insulated isothermal PCR (iiPCR) method for the efficient and rapid detection of Fusarium oxysporum (Fo), which is a fungus that infects various hosts and causes severe crop losses. The Fo iiPCR method was sensitive enough to detect up to 100 copies of standard DNA template and 10 fg of Fo genomic DNA. In addition, it could directly detect 1 pg of mycelium and 10 spores of Fo without DNA extraction. Our study compared the performance of Fo iiPCR to that of three published in planta molecular detection methods—conventional PCR, SYBR green-based real-time PCR, and hydrolysis probe-based real-time PCR—in field detection of Fo. All diseased field samples yielded positive detection results with high reproducibility when subjected to an Fo iiPCR test combined with a rapid DNA extraction protocol compared to Fo iiPCR with an automated magnetic bead-based DNA extraction protocol. Intraday and interday assays were performed to ensure the stability of this new rapid detection method. The results of detection of Fo in diseased banana pseudostem samples demonstrated that this new rapid detection method was suitable for field diagnosis of Fusarium wilt and had high F1 scores for detection (the harmonic mean of precision and recall of detection) for all asymptomatic and symptomatic Fo-infected banana samples. In addition, banana samples at four growth stages (seedling, vegetative, flowering and fruiting, and harvesting) with mild symptoms also showed positive detection results. These results indicate that this new rapid detection method is a potentially efficient procedure for on-site detection of Fo.