lateral flow devices

  • 文章类型: Journal Article
    随着全球消除犬介导的人类狂犬病的推动,对强大的狂犬病监测系统的需求变得越来越重要。许多国家正在努力改善狂犬病监测计划,因此,据报道,侧流装置(LFD)的使用正在增加。尽管他们已知的诊断局限性,以前的研究假设,与LFD相关的益处可能使它们对提高监测计划的整体稳健性有潜在的非常有用.为了测试这个,制定了最佳实践标准操作程序,该程序用于指导ADTECLFD作为桑给巴尔的诊断筛查工具的实施.在调查的前22个月里,83个样本接受了现场诊断筛查,加上随后的实验室确认,只检测到一个假阴性结果。此外,我们的调查结果表明,常规使用LFDs作为诊断性筛查工具导致每月接受狂犬病诊断的样本数量增加4倍,每年收集样本的病房数量增加3倍.我们的发现表明,LFD可以通过增加测试样本的数量和在远离实验室的地区促进诊断筛查,在提高监测系统的稳健性方面发挥值得注意的作用。他们的实施将,然而,需要通过与国际最佳实践保持一致的标准化协议进行仔细控制,以确保其合理使用。
    With the global impetus for the elimination of canine-mediated human rabies, the need for robust rabies surveillance systems has become ever more important. Many countries are working to improve their rabies surveillance programs and, as a result, the reported use of lateral flow devices (LFDs) is increasing. Despite their known diagnostic limitations, previous studies have hypothesised that the benefits associated with LFDs could make them potentially quite useful towards improving the overall robustness of surveillance programs. To test this, a best practice standard operating procedure was developed which was used to guide the implementation of the ADTEC LFD as a diagnostic screening tool in Zanzibar. Over the course of the first 22 months of this investigation, 83 samples were subjected to in-field diagnostic screening, coupled with subsequent laboratory confirmation, and only one false-negative result was detected. Furthermore, the findings of our investigation indicated that the routine use of LFDs as a diagnostic screening tool resulted in a four-fold increase in the number of samples subjected to rabies diagnosis per month and a three-fold increase in the number of wards where samples were collected per year. Our findings suggest that LFDs could play a noteworthy role in improving the robustness of surveillance systems by increasing the number of samples tested and promoting diagnostic screening in areas distant from laboratories. Their implementation would, however, need to be carefully controlled through standardised protocols that align with the international best practices to ensure their judicious use.
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  • 文章类型: Journal Article
    快速和早期发现猪的传染病非常重要,特别是对非洲猪瘟疑似病例实施控制措施,因为大多数受影响国家还没有有效和安全的疫苗。此外,尽管与ASF相比死亡率较低,但由于其高发病率(高达100%),因此对猪流感的分析具有重要意义.猪流感病毒A(SwIAV)在各国广泛分布,不断出现新的重组菌株,人类感染的危险强调了快速准确诊断的必要性。应根据情况应用几种诊断方法和商业方法,样本类型和正在实施的研究目标。在爆发的早期诊断中,使用各种PCR测定法进行的病毒基因组检测被证明是最灵敏和特异的技术。随着疾病的发展,血清学获得诊断价值,因为特异性抗体在疾病过程中出现较晚(ASF在感染后7-10天(DPI)和SwIAV在10-21DPI之间)。具有增强的灵敏度和特异性的商业试剂盒的持续开发是明显的。这篇综述旨在分析用于诊断ASF和SwIAV的最新进展和当前商业试剂盒。
    Rapid and early detection of infectious diseases in pigs is important, especially for the implementation of control measures in suspected cases of African swine fever (ASF), as an effective and safe vaccine is not yet available in most of the affected countries. Additionally, analysis for swine influenza is of significance due to its high morbidity rate (up to 100%) despite a lower mortality rate compared to ASF. The wide distribution of swine influenza A virus (SwIAV) across various countries, the emergence of constantly new recombinant strains, and the danger of human infection underscore the need for rapid and accurate diagnosis. Several diagnostic approaches and commercial methods should be applied depending on the scenario, type of sample and the objective of the studies being implemented. At the early diagnosis of an outbreak, virus genome detection using a variety of PCR assays proves to be the most sensitive and specific technique. As the disease evolves, serology gains diagnostic value, as specific antibodies appear later in the course of the disease (after 7-10 days post-infection (DPI) for ASF and between 10-21 DPI for SwIAV). The ongoing development of commercial kits with enhanced sensitivity and specificity is evident. This review aims to analyse recent advances and current commercial kits utilised for the diagnosis of ASF and SwIAV.
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  • 文章类型: Journal Article
    背景:对食品和饲料产品的不断增长的需求正在将食品价值链的能力延伸到极限。确保食品安全的关键步骤是检查小麦的霉菌毒素污染。然而,这种分析通常是通过相当复杂和昂贵的色谱方法进行的,如液相色谱-串联质谱(LC-MS/MS)。这些昂贵的方法需要大量的样品制备,这在食品供应链的不同点不容易进行。为了克服样品处理中的这些挑战,需要一种廉价的便携式样品制备装置,这需要低技能,用于快速样品到结果的霉菌毒素筛选。
    结果:我们描述了3D打印和可互连的模块,用于简单,集成和现场样品制备,包括小麦籽粒的研磨,和溶剂提取。我们对这些用于霉菌毒素筛选的3D打印模块进行了表征,并使用商业侧流装置(LFD)和内部验证的LC-MS/MS分析对实验室工厂进行了基准测试。基于研磨效率比较了不同的集成筛配置,我们选择了2毫米的筛子,允许在5分钟内研磨10克小麦。此外,第一次用户能够以最少的指令操作研磨机模块。使用开发的3D打印原型证明了在监管/法定限值(1.25mgkg-1)下筛选天然污染样品中的脱氧雪腐镰刀菌烯醇(DON)。整个过程只需要15分钟,从样品制备到筛选结果。结果显示LFD和LC-MS/MS之间有明显的相关性(R2=0.96)。
    结论:我们的研究结果证明了3D打印样品处理设备作为现有分析程序的宝贵扩展的潜力。便于现场实施快速测定谷物中霉菌毒素的方法。提出的原型价格低廉,材料成本为2.5€,依赖于可生物降解的3D打印丝,可以用消费级打印机生产,使原型随时可用。作为未来的视角,我们开发的工具包的模块化特征将允许适应其他硬质食品商品,而不是确定小麦中的DON。
    BACKGROUND: The increasing demand for food and feed products is stretching the capacity of the food value chain to its limits. A key step for ensuring food safety is checking for mycotoxin contamination of wheat. However, this analysis is typically performed by rather complex and expensive chromatographic methods, such as liquid chromatography-tandem mass spectrometry (LC-MS/MS). These costly methods require extensive sample preparation that is not easily carried out at different points along the food supply chain. To overcome such challenges in sample processing, an inexpensive and portable sample preparation device was needed, that required low skill, for rapid sample-to-result mycotoxin screening.
    RESULTS: We describe 3D-printed and interconnectable modules for simple, integrated and on-site sample preparation, including grinding of wheat kernels, and solvent-based extraction. We characterized these 3D-printed modules for mycotoxin screening and benchmarked them against a laboratory mill using commercial lateral flow device(s) (LFD) and in-house validated LC-MS/MS analysis. Different integrated sieve configurations were compared based on grinding efficiency, and we selected a sieve size of 2 mm allowing grinding of 10 g of wheat within 5 min. Moreover, 10 first time-users were able to operate the grinder module with minimal instructions. Screening for deoxynivalenol (DON) in naturally contaminated samples at the regulatory/legal limit (1.25 mg kg-1) was demonstrated using the developed 3D-printed prototype. The whole process only takes 15 min, from sample preparation to screening result. The results showed a clear correlation (R2 = 0.96) between the LFD and LC-MS/MS.
    CONCLUSIONS: Our findings demonstrate the potential of 3D-printed sample handling equipment as a valuable extension of existing analytical procedures, facilitating the on-site implementation of rapid methods for the determination of mycotoxins in grains. The presented prototype is inexpensive with material costs of 2.5€, relies on biodegradable 3D printing filament and can be produced with consumer-grade printers, making the prototype readily available. As a future perspective, the modular character of our developed tool kit will allow for adaptation to other hard food commodities beyond the determination of DON in wheat.
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  • 文章类型: Multicenter Study
    扩大侧流装置(LFD)用于动物狂犬病诊断的使用可以帮助减轻狂犬病的广泛漏报。然而,这受到以往研究数量有限和样本量小的阻碍.为了克服这个限制,我们用更大的样本量进行了多中心研究,以评估ADTECLFD对动物死后狂犬病诊断的诊断准确性.菲律宾的13个政府动物诊断实验室参与了这项研究,在2021年8月至2022年10月期间,使用直接荧光抗体检测(DFAT)和ADTECLFD对791只疑似狂犬病的动物进行了检测.LFD的敏感性为96.3%[95%置信区间(CI):94.1%-97.9%],特异性为99.7%(95%CI:98.4%-100%)。值得注意的是,假阴性结果更可能发生在前几年狂犬病样本年处理量较低的实验室(调整后比值比4.97,95%CI:1.49-16.53).在这项多中心研究中,LFD诊断动物狂犬病的高敏感性和特异性,与DFAT相比,被证明,然而,关于假阴性结果的担忧仍然存在。在狂犬病样本处理经验有限的地区,在实施过程中,必须提供全面的培训和认真的关注。
    Expansion of the use of lateral flow devices (LFD) for animal rabies diagnosis can help mitigate the widespread underreporting of rabies. However, this has been hindered by the limited number and small sample size of previous studies. To overcome this limitation, we conducted a multicenter study with a larger sample size to assess the diagnostic accuracy of the ADTEC LFD for postmortem rabies diagnosis in animals. Thirteen governmental animal diagnostic laboratories in the Philippines were involved in this study, and 791 animals suspected of having rabies were tested using both the direct fluorescence antibody test (DFAT) and ADTEC LFD between August 2021 and October 2022. The LFD demonstrated a sensitivity of 96.3% [95% confidence interval (CI): 94.1%-97.9%] and a specificity of 99.7% (95% CI: 98.4%-100%). Notably, false-negative results were more likely to occur in laboratories with lower annual processing volumes of rabies samples in the previous years (adjusted odds ratio 4.97, 95% CI: 1.49-16.53). In this multicenter study, the high sensitivity and specificity of the LFD for the diagnosis of animal rabies, compared to that of the DFAT, was demonstrated, yet concerns regarding false-negative results remain. In areas with limited experience in processing rabies samples, it is essential to provide comprehensive training and careful attention during implementation.
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  • 文章类型: Journal Article
    这项研究的目的是确定最佳条件,以提高金和银纳米颗粒抗玉米赤霉烯酮抗体缀合物的稳定性,用于侧流免疫层析测定(LFIA)。Turkevich-Frens方法用于合成金纳米粒子(AuNPs),直径在10到110纳米之间。使用硼氢化钠作为还原剂合成尺寸分布为2.5至100nm的银纳米颗粒(AgNP)。AuNP和AgNP聚集的开始发生在150mM和80mMNaCl浓度,分别。在1.2mM的K2CO3浓度下获得稳定的Au和Ag纳米颗粒-抗体缀合物,对应于约7的pH值。最后,在抗体浓度为4和6µg/mL时,Au和Ag纳米颗粒与抗玉米赤霉烯酮抗体的缀合程度最高.缀合条件的优化可以有助于纳米颗粒及其抗体缀合物的更好稳定性,并且可以改善生物传感侧流装置中生物报告分子结果的再现性。
    The aim of this research is to define optimal conditions to improve the stability of gold and silver nanoparticles\' anti-zearalenone antibody conjugates for their utilisation in lateral flow immunochromatographic assay (LFIA). The Turkevich-Frens method was used to synthesise gold nanoparticles (AuNPs), which were between 10 and 110 nm in diameter. Silver nanoparticles (AgNPs) with a size distribution of 2.5 to 100 nm were synthesised using sodium borohydride as a reducing agent. The onset of AuNP and AgNP aggregation occurred at 150 mM and 80 mM NaCl concentrations, respectively. Stable Au and Ag nanoparticle-antibody conjugates were achieved at 1.2 mM of K2CO3 concentration, which corresponds to the pH value of ≈7. Lastly, the highest degree of conjugation between Au and Ag nanoparticles and anti-zearalenone antibodies was at 4 and 6 µg/mL of antibody concentrations. The optimisation of the conjugation conditions can contribute to better stability of nanoparticles and their antibody conjugate and can improve the reproducibility of results of bioreporter molecules in biosensing lateral flow devices.
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  • 文章类型: Journal Article
    侧流装置(LFD)是近年来取得实质性进展的简单科学工具。它们已用于许多领域,包括肉类行业,以检测疾病标志物,确定肉类新鲜度或肉类种类。他们是,因此,在混合动物物种的肉类掺假研究中具有重要意义,因为食品成分的真实性是一个涉及健康的严重问题,经济,legal,和宗教问题。猪肉掺假是全球肉类行业最重要的问题之一。在这次审查中,我们讨论了各种类型的LFD和最近的研究开发LFD作为检测肉类产品中猪添加剂的真实性工具,以及监管当局如何在其工作流程中采用LFD。尽管有快速性的好处,简单,低成本,高灵敏度,和特异性,研究人员在使用LFD作为最终确认测试时面临挑战。建议将LFD作为清真身份验证方法进行全球化使用的未来方向。
    Lateral flow devices (LFDs) are straightforward scientific tools that have made substantial advances in recent years. They have been used in many fields including the meat industry to detect disease markers, determine meat freshness or meat species determination. They are, therefore, significant in the research of meat adulteration by mixed animal species, because food component authenticity is a serious concern encompassing health, economic, legal, and religious issues. Pork adulteration is one of the most crucial issues in the global meat industry. In this review, we discuss the various types of LFDs and recent research on the development of LFDs as an authenticity tool for detecting pig additives in meat-based products, and how regulatory authorities could adopt LFDs for their workflows. Despite the benefits of rapidity, simplicity, low cost, high sensitivity, and specificity, researchers face challenges when using LFD as a final confirmation test. Future directions are suggested for globalising the use of LFD as a halal authentication method.
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  • 文章类型: Journal Article
    狂犬病病毒的分子分析可以提供准确的诊断和遗传多样性信息。由于生物危害风险和可分解性,将狂犬病脑样本从偏远地区运输到中央实验室具有挑战性。我们研究了使用过的侧向流设备(LFD)用于后续分子分析的实用性,并评估了必要的存储温度。使用从使用过的LFD条提取的RNA,我们使用LN34引物组扩增短片段(165bp)用于狂犬病病毒检测,使用P1-304引物组扩增整个N基因扩增子的长片段(1,506bp)用于系统发育分析。在储存在冰箱中的71个使用过的LFD和储存在室温下的64个使用过的LFD中,LN34检测显示出高灵敏度(96.2%和100%,分别)用于狂犬病的诊断,无论储存温度如何。与在冷藏温度下储存的那些相比,当使用在室温下储存的使用过的LFD的P1-304引物组时,观察到狂犬病诊断的灵敏度显著降低(20.9%对100%;P<0.05)。使用由P1-304RT-PCR测定产生的扩增子成功地进行了随后的测序和系统发育分析。因此,使用的LFD是用于狂犬病病毒RNA检测和序列分析的有前途的资源。通过RT-PCR检测病毒,扩增一个短片段,无论使用的LFD的储存温度如何,都是可能的。然而,建议冷藏用于长片段的RT-PCR扩增,以进行系统发育分析。
    Molecular analysis of rabies virus can provide accurate diagnosis and information on its genetic diversity. The transportation of rabies brain samples from remote areas to a central laboratory is challenging owing to biohazard risks and decomposability. We investigated the utility of used lateral flow devices (LFDs) for subsequent molecular analysis and assessed the necessary storage temperatures. Using RNA extracted from used LFD strips, we performed conventional reverse transcription-PCR (RT-PCR) using an LN34 primer set to amplify short fragments (165 bp) for rabies virus detection and the P1-304 primer set to amplify long fragments of the entire N gene amplicon (1,506 bp) for phylogenetic analysis. Among 71 used LFDs stored in a refrigerator and 64 used LFDs stored at room temperature, the LN34 assay showed high sensitivities (96.2% and 100%, respectively) for the diagnosis of rabies, regardless of the storage temperature. A significant reduction in the sensitivity of rabies diagnosis was observed when using the P1-304 primer set for used LFDs stored at room temperature compared to those stored at refrigeration temperature (20.9% versus 100%; P < 0.05). Subsequent sequencing and phylogenetic analysis were successfully performed using the amplicons generated by the P1-304 RT-PCR assays. Used LFDs are thus promising resources for rabies virus RNA detection and sequence analysis. Virus detection via RT-PCR, amplifying a short fragment, was possible regardless of the storage temperature of the used LFDs. However, refrigerated storage is recommended for RT-PCR amplification of long fragments for phylogenetic analysis.
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  • 文章类型: Journal Article
    SARS-CoV-2的不断出现的变体和危及生命的后果引起了全世界对人类健康的关注,需要快速准确的即时诊断,以限制COVID-19的传播。尽管如此,然而,对COVID-19进行此类诊断的可用性仍然是遏制疫情爆发的主要限速因素。除了常规的逆转录聚合酶链反应,环介导等温扩增(LAMP)检测已成为检测COVID-19的快速有效系统。本研究旨在开发基于RT-LAMP的检测系统,用于检测N,ORF1ab,E,SARS-CoV-2基因组的S基因,使用分光光度法对最终产物进行定量,纸基横向流动装置,和电化学传感器。分光光度法显示N的LOD为10agµL-1,ORF1ab,SARS-CoV-2中的E基因和S基因的100agµL-1。开发的侧流设备显示SARS-CoV-2中所有四个基因靶标的LOD为10agµL-1。为N基因开发的电化学传感器显示LOD和E条灵敏度分别为log1.79±0.427pgµL-1和log0.067µA/pgµL-1/mm2。开发的检测系统在2020年和2021年的COVID-19疫情中得到了临床样本的验证。这种多基因靶标方法可以在测试设施和护理点设置中使用各种分析技术的组合有效地检测新出现的COVID-19变体。
    Consistently emerging variants and the life-threatening consequences of SARS-CoV-2 have prompted worldwide concern about human health, necessitating rapid and accurate point-of-care diagnostics to limit the spread of COVID-19. Still, However, the availability of such diagnostics for COVID-19 remains a major rate-limiting factor in containing the outbreaks. Apart from the conventional reverse transcription polymerase chain reaction, loop-mediated isothermal amplification-based (LAMP) assays have emerged as rapid and efficient systems to detect COVID-19. The present study aims to develop RT-LAMP-based assay system for detecting multiple targets in N, ORF1ab, E, and S genes of the SARS-CoV-2 genome, where the end-products were quantified using spectrophotometry, paper-based lateral-flow devices, and electrochemical sensors. The spectrophotometric method shows a LOD of 10 agµL-1 for N, ORF1ab, E genes and 100 agµL-1 for S gene in SARS-CoV-2. The developed lateral-flow devices showed an LOD of 10 agµL-1 for all four gene targets in SARS-CoV-2. An electrochemical sensor developed for N-gene showed an LOD and E-strip sensitivity of log 1.79 ± 0.427 pgµL-1 and log 0.067 µA/pg µL-1/mm2, respectively. The developed assay systems were validated with the clinical samples from COVID-19 outbreaks in 2020 and 2021. This multigene target approach can effectively detect emerging COVID-19 variants using combination of various analytical techniques at testing facilities and in point-of-care settings.
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  • 文章类型: Journal Article
    在过去的几十年中,蜜蜂群落的死亡率异常。殖民地暴露于生物和非生物压力,包括人类压力引起的景观变化。现代农业乃至林业,依赖农药投入,这些化学物质已被认为是菌落损失的主要原因之一。新烟碱是世界范围内使用的一类常见的杀虫剂,专门用于杀死害虫,啶虫脒是欧盟唯一允许在户外使用的新烟碱。为了评估蜜蜂在野外条件下接触啶虫脒的情况,以及测试使用原位工具监测农药残留的情况,在五个桉树中安装了两个蜜蜂殖民地。具有不同区域的种植园在常见的喷洒事件中施用Epik®(活性物质:啶虫脒)以控制桉树象鼻虫害虫。鲜花,新鲜的花蜜,收集蜜蜂和菌落产品样品并分析啶虫脒残留物的存在。我们的主要发现是(1)在喷洒区域外收集的样品中发现了啶虫脒残留,(2)转运到菌落中的残留物量随喷洒面积的大小而增加,(3)根据计算的暴露毒性比(ETR)值,喷洒高达22%的蜜蜂觅食区域不会伤害殖民地,(4)菌落产物可以作为有效的工具来监测啶虫脒的菌落积累和(5)使用侧流装置(LFDs)可以是一种廉价的,快速和容易的工具在现场应用,评估景观和菌落产品中啶虫脒残留物的存在。
    Honey bee colonies have shown abnormal mortality rates over the last decades. Colonies are exposed to biotic and abiotic stressors including landscape changes caused by human pressure. Modern agriculture and even forestry, rely on pesticide inputs and these chemicals have been indicated as one of the major causes for colony losses. Neonicotinoids are a common class of pesticides used worldwide that are specific to kill insect pests, with acetamiprid being the only neonicotinoid allowed to be applied outdoors in the EU. To evaluate honeybees\' exposure to acetamiprid under field conditions as well as to test the use of in-situ tools to monitor pesticide residues, two honeybee colonies were installed in five Eucalyptus sp. plantations having different area where Epik® (active substance: acetamiprid) was applied as in a common spraying event to control the eucalyptus weevil pest. Flowers, fresh nectar, honey bees and colony products samples were collected and analyzed for the presence of acetamiprid residues. Our main findings were that (1) acetamiprid residues were found in samples collected outside the spraying area, (2) the amount of residues transported into the colonies increased with the size of the sprayed area, (3) according to the calculated Exposure to Toxicity Ratio (ETR) values, spraying up to 22 % of honeybees foraging area does not harm the colonies, (4) colony products can be used as a valid tool to monitor colony accumulation of acetamiprid and (5) the use of Lateral Flow Devices (LFDs) can be a cheap, fast and easy tool to apply in the field, to evaluate the presence of acetamiprid residues in the landscape and colony products.
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  • 文章类型: Journal Article
    Lateral flow immuno-assays, such as the home pregnancy test, are rapid point-of-care diagnostics that use antibody-coated nanoparticles to bind antigens/analytes (e.g., viruses, toxins or hormones). Ease of use, no need for centralized infrastructure and low-cost, makes these devices appealing for rapid disease identification, especially in low-resource environments. Here glycosylated polymer-coated nanoparticles are demonstrated for the sensitive, label-free detection of lectins in lateral flow and flow-through. The systems introduced here use glycans, not antibodies, to provide recognition: a \"lateral flow glyco-assay,\" providing unique biosensing opportunities. Glycans are installed onto polymer termini and immobilized onto gold nanoparticles, providing colloidal stability but crucially also introducing assay tunability and selectivity. Using soybean agglutinin and Ricinus communis agglutinin I (RCA120 ) as model analytes, the impact of polymer chain length and nanoparticle core size are evaluated, with chain length found to have a significant effect on signal generation-highlighting the need to control the macromolecular architecture to tune response. With optimized systems, lectins are detectable at subnanomolar concentrations, comparable to antibody-based systems. Complete lateral flow devices are also assembled to show how these devices can be deployed in the \"real world.\" This work shows that glycan-binding can be a valuable tool in rapid diagnostics.
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