Development of a CRISPR-based diagnostic platform for rapid detection of antimicrobial resistance genes in clinical isolates using Cas12a in a point-of-care format

Project Abstract

This study reports the development and validation of a CRISPR-based diagnostic platform that enables rapid, sensitive, and specific detection of antimicrobial resistance (AMR) genes directly from clinical isolates in a point-of-care (POC) setting, leveraging Cas12a collateral cleavage activity and a streamlined workflow. The platform integrates sample preparation, isothermal amplification, CRISPR-Cas12a–guided detection, and a user-friendly readout into a compact, field-deployable assay designed to inform timely antimicrobial stewardship decisions. We engineered a modular assay architecture targeting a panel of clinically relevant resistance determinants, including beta-lactamase variants (blaCTX-M, blaKPC, blaNDM), mecA/mecC (MRSA), vanA/vanB (VRE), and carbapenemase-encoding genes, as well as common plasmid-mediated determinants such as qnr, tet, and dfr genes. Guide RNAs were meticulously selected for high on-target activity and minimal cross-reactivity, and the Cas12a enzyme was optimized for robust collateral cleavage of single-stranded reporters under physiologically relevant temperatures, enabling rapid signal generation in under 60 minutes from sample to answer. We evaluated the analytical performance of the platform using a panel of well-characterized bacterial reference strains and diverse clinical isolates, establishing limits of detection in the low-copy-number range and demonstrating specificity against non-target organisms. Comprehensive optimization of reaction conditions, including magnesium concentration, buffer composition, and thermal control, ensured compatibility with low-resource settings, where precise instruments may be scarce. The readout was developed with both fluorometric and lateral-flow modalities, permitting quantitative and qualitative results that can be interpreted with minimal training. The lateral-flow readout was validated against standard culture-based antimicrobial susceptibility testing and molecular assays, showing concordance rates suitable for clinically actionable reporting. In addition to analytical validation, this work includes a prospective clinical evaluation in a high-throughput workflow, simulating real-world POCT deployment in outpatient clinics and urgent care centers. Turnaround times, user satisfaction, and hands-on time were systematically recorded to identify bottlenecks and opportunities for workflow integration. We also performed a partial cost analysis and a risk assessment to evaluate scalability, supply chain considerations, and biosafety implications for routine use. The integration of a portable reader or even a smartphone-based interface was explored to enhance data capture, geotagging, and electronic medical record interoperability, facilitating real-time AMR surveillance and outbreak response. The study demonstrates that a Cas12a-based diagnostic platform can provide rapid, accurate, and accessible detection of key AMR determinants at the point of care, with potential to transform antimicrobial stewardship, infection control, and public health surveillance by enabling timely, genotype-informed therapy choices and containment of resistant infections in resource-limited environments.

Project Overview

What This Project Is About

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A straightforward introduction to using a gene-editing–inspired tool (Cas12a) to detect antibiotic resistance genes quickly at the point of care, such as clinics or clinics’ devices. The project explores how a user-friendly test could tell if a bacterial sample carries resistance genes, enabling faster treatment decisions.

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The Problem It Addresses

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Many infections are treated without knowing which antibiotics will work. Traditional labs can take days to identify resistance, delaying effective care and contributing to antibiotic resistance. This project aims to shorten the time to obtain a reliable resistance profile directly from patient samples.

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Objectives of the Project

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1. Explain how Cas12a can be used to detect resistance genes.
2. Design a simple, portable test format suitable for point-of-care use.
3. Demonstrate the test’s ability to distinguish resistant from susceptible bacteria.
4. Evaluate accuracy, speed, and ease of use with mock clinical samples.
5. Assess potential limitations and safety considerations for deployment.

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What You Will Do Step by Step

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1. Review background material on CRISPR-based diagnostics and antimicrobial resistance genes.

2. Select target resistance genes to detect and design primers or guides.

3. Build a simple assay prototype and a user-friendly readout (e.g., color change or small device readout).

4. Test the assay with prepared samples to measure sensitivity and specificity.

5. Compare results to standard lab methods and document differences.

6. Analyze data to determine real-world feasibility and limitations.

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Expected Outcome

A lightweight, rapid diagnostic approach capable of indicating the presence of key antimicrobial resistance genes in clinical samples, with a clear protocol for potential field use and guidance on further development and validation.