CRISPR/Cas12a-Based Assay for the Rapid and High-Sensitivity Detection of Streptococcus Agalactiae Colonization in Pregnant Women with Premature Rupture of Membrane

Abstract

Background Streptococcus agalactiae or group B Streptococcus (GBS) is a leading infectious cause of neonatal morbidity and mortality. This study aims to establish a novel method, termed as the CRISPR-GBS assay, for the rapid and sensitive detection of GBS that is based on the clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein (Cas) system. Results The CRISPR-GBS assay detected GBS in the samples within 35 min. The limit of detection was as low as 5 copies/µL and showed no cross-reactivity with other microorganisms. The clinical performance was assessed using vaginal or cervical swab samples that were collected from 179 pregnant women with premature rupture of membrane. Compared with the culture-based matrix-assisted laser desorption ionization time-of-flight mass spectrometry method, the CRISPR-GBS assay demonstrated a sensitivity of 96.64% (144/149, 95% confidence interval [CI] = 92.39–98.56%) and a specificity of 100% (30/30, 95% CI = 88.65–100%). It also had a high concordance rate of 98.88% with the real-time fluorescence polymerase chain reaction assay. Conclusions The CRISPR-GBS assay can be used for rapid and high-sensitivity detection of GBS in a simple and cost-efficient manner; thus, it offers a novel method for intrapartum screening.