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 10 1 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 hours, 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. • By using magnetic separation techniques and mPCR-CE, our assay greatly reduces the problems of impurity interference caused by blood matrix substances. • This method can simultaneously analyze multiple bacteria. Ten (10) cfu/mL of Staphylococcus aureus , Escherichia coli , Enterococcus faecalis and Klebsiella pneumoniae was accurately and reliably detected. • The practicability of this method has been validated by 100 clinical samples and there were no false positives. 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, which 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 10 1 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 hours, 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.