CRISPR-based test spots aminoglycoside resistance gene in 70 minutes

Researchers in Wuhan, China, have developed a rapid diagnostic assay that detects armA, a gene that confers high-level resistance to aminoglycoside antibiotics in bacterial pathogens. The method combines multiple cross displacement amplification (MCDA) with the CRISPR/Cas12a system, and the team reports that the entire workflow can be completed in about 70 minutes.

Because this modification produces high-level resistance, surveillance for enzyme-producing strains is an important part of controlling drug resistance in both clinical and livestock settings, according to the study authors.

The published workflow breaks down into four steps: genomic DNA extraction takes 15 minutes, the MCDA reaction runs for 40 minutes, CRISPR/Cas12a-mediated cleavage takes 5 minutes, and fluorescence detection adds another 10 minutes.

In analytical specificity testing, the assay yielded positive results for all armA-positive isolates and negative results for all non-armA samples included in the study. This indicates that, within the panel tested, the assay reliably distinguished samples carrying the resistance gene from those that did not.

The reported sensitivity of the MCDA-CRISPR/Cas12a assay reached a detection limit as low as 10 copies per microliter of armA-positive plasmid DNA. This level of detection reflects performance on purified plasmid DNA under controlled laboratory conditions rather than directly on complex clinical specimens.

To evaluate real-world performance, the researchers tested 129 cultured clinical isolates that had been validated by whole-genome sequencing. The assay achieved 100 percent concordance with the sequencing-based reference for armA detection across this isolate panel, suggesting the method can match genomic gold-standard results when applied to cultured bacterial isolates.

The authors position the technique as a rapid and accurate diagnostic approach for laboratory-based surveillance of armA in clinical and livestock settings. They note that adaptation for point-of-care use would require further simplification and additional validation, so the current version is intended for laboratory environments rather than bedside or field deployment.

Subject of Research: A rapid MCDA-CRISPR/Cas12a diagnostic assay for detecting the aminoglycoside resistance gene armA in bacterial isolates

Article Title: Highly sensitive and specific detection of aminoglycoside resistance methylase gene armA by multiple cross displacement amplification-CRISPR/Cas12a technique

Article References: Gong, L., Wang, J., Zhang, Y., Xu, H., Liu, X., Chen, X., Li, M., Li, Y., Wu, L., Wang, Y., & Shen, X. (2026). Highly sensitive and specific detection of aminoglycoside resistance methylase gene armA by multiple cross displacement amplification-CRISPR/Cas12a technique. Frontiers in Cellular and Infection Microbiology, 16, Article 1947114. https://doi.org/10.3389/fcimb.2026.1947114

Image Credits: AI Generated

DOI: 10.3389/fcimb.2026.1947114

Keywords: armA, aminoglycoside resistance, CRISPR/Cas12a, MCDA, 16S rRNA methylase, diagnostics, antimicrobial resistance, surveillance, isothermal amplification, clinical isolates, Highly, sensitive