Fast, portable and sensitive detection of group B streptococcus DNA using one-pot MIRA-CRISPR system with suboptimal PAM

Talanta. 2024 Nov 1:279:126574. doi: 10.1016/j.talanta.2024.126574. Epub 2024 Jul 15.

Abstract

The group B Streptococcus (GBS) can generate vertical transmission to infants during delivery, has been seriously threatening the health of infants. Rapid and accurate prenatal GBS diagnosis for pregnant women is a deterministic blueprint to avoid infant viruses. Here, we developed an extraction-free nucleic acid isothermal amplification/CRISPR-Cas12a cutting one-pot system for GBS diagnostic assay by using suboptimal protospacer adjacent motifs, effectively avoiding multiple handling steps and uncapping contamination. The GBS diagnosis assay based on a one-pot system was validated by using fluorescent technique and lateral flow assay strips, exhibited fantastic specificity, accuracy and sensitivity with a limit of detection of 32 copies per reaction (0.64 copies/μL). Moreover, a portable device was constructed and integrated with the one-pot system to realize the GBS detection without professional and scene restrictions, it showed excellent performance in clinical sample detection, which achieved optical and portable GBS detection for point-of-care testing or home-self testing.

Keywords: CRISPR; Group B Streptococcus; Isothermal amplification; One-pot assay.

MeSH terms

  • CRISPR-Cas Systems* / genetics
  • DNA, Bacterial* / analysis
  • DNA, Bacterial* / genetics
  • Female
  • Humans
  • Limit of Detection
  • Nucleic Acid Amplification Techniques* / methods
  • Pregnancy
  • Streptococcal Infections / diagnosis
  • Streptococcus agalactiae* / genetics
  • Streptococcus agalactiae* / isolation & purification

Substances

  • DNA, Bacterial