CRISPR Cas12a based assay for the detection of streptococcus agalactiae colonization in pregnant women with premature rupture of membrane.xlsx

<b>Aims: </b><i>Streptococcus agalactiae</i> (GBS) is a leading infectious cause of neonatal morbidity and mortality. It is essential to establish a rapid and sensitive method for the detection of GBS.<b>Methods and Results:</b> This study developed a CRISPR-GBS assay that combines recombinase polymerase amplification (RPA) and CRISPR/Cas12a for GBS detection. The detection process can be completed within 35 min, compared to 85 min for quantitative real-time PCR (qPCR) assay and 48-72h for culture method. The limit of detection (LoD) was as low as 5 copies μL^-1 and no cross-reaction with other microorganisms was observed. The clinical performance of CRISPR-GBS assay was assessed using vaginal or cervical swab samples 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 (culture-MS) 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 qPCR assay. <b>Conclusions:</b> The established CRISPR-GBS platform can detect GBS in a rapid, accurate, easy-to-operate and cost-efficient manner. <b>Significance and Impact of the Study: </b>The CRISPR-GBS assay has promising prospects as a clinically useful point-of-care test for intrapartum screening of GBS infection. <b></b>