Rapid detection of four pathogens in bloodstream infection by antimicrobial peptide capture combined with multiplex PCR and capillary electrophoresis

Bloodstream infection (BSI) is a common and serious infection that threatens the life of patients. In this study, a rapid method combining magnetic separation techniques and multiplex PCR-based capillary electrophoresis (mPCR-CE) was developed to detect four pathogens causing BSI. Taking advantage of the binding capacity with the cell membrane, the antimicrobial peptides melittin was connected to magnetic beads as a broad-spectrum bacterial capture element. It was used to capture pathogenic bacteria in whole blood. The detection limit of this proposed method was significantly lower than that of the common PCR method, reaching 101 CFU/mL with excellent specificity. The overall clinical sensitivity was 90%, and the clinical specificity was 100%. There were no false positives for testing another 100 clinical samples suspected of bloodstream infections. The detection platform took only 3–4 h, which is obviously shorter than the identification time of the traditional methods. Our method possesses tremendous clinical application potential for its advantages in detecting mixed bacterial infections.