Paper‐based point‐of‐care test with xeno nucleic acid probes

Implementing effective monitoring strategies is fundamental to protect crops from pathogens and to ensure the food supply as the world population continues to grow. This is especially important for emergent plant pathogens such as tomato brown rugose fruit virus (ToBRFV), which overcomes the genetic resistance resources used in tomato breeding against tobamoviruses and has become pandemic in less than a decade. Here we report the development of a CRISPR/Cas12a-based test to detect ToBRFV in the laboratory and potentially in a field setting. Using different tobamoviruses to assess specificity, our test showed a clear positive signal for ToBRFV-infected samples, while no cross-reactivity was observed for closely related viruses. Next, we compared the limit of detection of our CRISPR-based test with a reference real-time quantitative PCR test widely used, revealing similar sensitivities for both tests. Finally, to reduce complexity and achieve field-applicability, we used a fast nucleic acid purification step and compared its results side-to-side with those of a commonly used column-mediated protocol. The rapid protocol saved time and resources but at the expense of sensitivity. However, it still may be useful to confirm ToBRFV detection in samples with incipient symptoms of infection. Although there is room for improvement, to our knowledge this is the first field-compatible CRISPR-based test to detect ToBRFV which combines isothermal amplification with a simplified nucleic acid extraction protocol.

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Testing for resistance: Point-of-care testing as a communicational tool in antibiotic prescribing

Communication & Medicine ◽

10.1558/cam.32191 ◽

2018 ◽

Vol 14 (3) ◽

pp. 229-240

Author(s):

Johanna Lindell

Keyword(s):

Point Of Care ◽

Rapid Test ◽

Antibiotic Use ◽

Treatment Recommendation ◽

Antibiotic Prescribing ◽

Communicative Practices ◽

Effective Strategies ◽

Reactive Protein ◽

Point Of Care Test ◽

Test Result

As antibiotic resistance becomes a growing health emergency, effective strategies are needed to reduce inappropriate antibiotic use. In this article, one such strategy – communicative practices associated with the C-reactive protein point-of care test – is investigated. Building on a collection of 31 videorecorded consultations from Danish primary care, and using conversation analysis, this study finds that the rapid test can be used throughout the consultation to incrementally build the case for a nonantibiotic treatment recommendation, both when the test result is forecast and reported. The study also finds that the format of reports of elevated results differs from that of ‘normal’ results, resulting in a subtle shift of authority from doctor to test.

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Gold-Aptamer-Nanoconstructs Engineered to Detect Conserved Enteroviral Nucleic Acid Sequences

10.26434/chemrxiv.8312324.v1 ◽

2019 ◽

Author(s):

Veeren Chauhan ◽

Mohamed M Elsutohy ◽

C Patrick McClure ◽

Will Irving ◽

Neil Roddis ◽

...

Keyword(s):

Nucleic Acid ◽

In Silico ◽

Point Of Care ◽

Lateral Flow ◽

Nucleic Acid Sequence ◽

In Silico Screening ◽

Lateral Flow Assays ◽

Life Threatening ◽

Software And Hardware ◽

Nucleic Acid Sequences

Enteroviruses are a ubiquitous mammalian pathogen that can produce mild to life-threatening disease. Bearing this in mind, we have developed a rapid, accurate and economical point-of-care biosensor that can detect a nucleic acid sequences conserved amongst 96% of all known enteroviruses. The biosensor harnesses the physicochemical properties of gold nanoparticles and aptamers to provide colourimetric, spectroscopic and lateral flow-based identification of an exclusive enteroviral RNA sequence (23 bases), which was identified through in silico screening. Aptamers were designed to demonstrate specific complementarity towards the target enteroviral RNA to produce aggregated gold-aptamer nanoconstructs. Conserved target enteroviral nucleic acid sequence (≥ 1x10-7 M, ≥1.4×10-14 g/mL), initiates gold-aptamer-nanoconstructs disaggregation and a signal transduction mechanism, producing a colourimetric and spectroscopic blueshift (544 nm (purple) > 524 nm (red)). Furthermore, lateral-flow-assays that utilise gold-aptamer-nanoconstructs were unaffected by contaminating human genomic DNA, demonstrated rapid detection of conserved target enteroviral nucleic acid sequence (< 60 s) and could be interpreted with a bespoke software and hardware electronic interface. We anticipate our methodology will translate in-silico screening of nucleic acid databases to a tangible enteroviral desktop detector, which could be readily translated to related organisms. This will pave-the-way forward in the clinical evaluation of disease and complement existing strategies at overcoming antimicrobial resistance.

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Point-of-care Test for Diagnosis of Peritonitis in Peritoneal Dialysis Patients

Case Medical Research ◽

10.31525/ct1-nct04070196 ◽

2019 ◽

Author(s):

Keyword(s):

Peritoneal Dialysis ◽

Point Of Care ◽

Dialysis Patients ◽

Point Of Care Test

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Novel High Sensitivity Tuberculosis Point-of-Care Test for People Living with HIV

SSRN Electronic Journal ◽

10.2139/ssrn.3254479 ◽

2018 ◽

Cited By ~ 2

Author(s):

Tobias Broger ◽

Bianca Sossen ◽

Elloise du Toit ◽

Andrew D. Kerkhoff ◽

Charlotte Schutz ◽

...

Keyword(s):

Point Of Care ◽

High Sensitivity ◽

People Living With Hiv ◽

Point Of Care Test ◽

Living With Hiv

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A glucose meter interface for point-of-care gene circuit-based diagnostics

Nature Communications ◽

10.1038/s41467-020-20639-6 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Evan Amalfitano ◽

Margot Karlikow ◽

Masoud Norouzi ◽

Katariina Jaenes ◽

Seray Cicek ◽

...

Keyword(s):

Nucleic Acid ◽

Synthetic Biology ◽

Molecular Diagnostics ◽

Point Of Care ◽

Low Cost ◽

Gene Circuit ◽

Reporter Systems ◽

Glucose Meter ◽

Pandemic Response ◽

Glucose Output

AbstractRecent advances in cell-free synthetic biology have given rise to gene circuit-based sensors with the potential to provide decentralized and low-cost molecular diagnostics. However, it remains a challenge to deliver this sensing capacity into the hands of users in a practical manner. Here, we leverage the glucose meter, one of the most widely available point-of-care sensing devices, to serve as a universal reader for these decentralized diagnostics. We describe a molecular translator that can convert the activation of conventional gene circuit-based sensors into a glucose output that can be read by off-the-shelf glucose meters. We show the development of new glucogenic reporter systems, multiplexed reporter outputs and detection of nucleic acid targets down to the low attomolar range. Using this glucose-meter interface, we demonstrate the detection of a small-molecule analyte; sample-to-result diagnostics for typhoid, paratyphoid A/B; and show the potential for pandemic response with nucleic acid sensors for SARS-CoV-2.

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