Capture and identification of bacteria from blood clam (Scapharca subcrenata) based on multi-targeted immunomagnetic beads and MALDI-TOF MS

In the present study, magnetic beads (MBs) conjugated with multiple monoclonal antibodies were constructed for capturing bacteria from food matrices. Escherichia coli ( E. coli ), Klebsiella pneumoniae , and Vibrio parahaemolyticus were taken as model bacteria, and multi-antibodies functionalized MBs (multi-Abs@MBs) were utilized for their capture. The excellency of the specificity and reproducibility of the present protocol was demonstrated by capturing E. coli , K. pneumoniae , and V . parahaemolyticus from water medium, and blood clam ( Scapharca subcrenata ) protein extracts, respectively. The presence of 10 CFU/mL of bacteria is still detectable. The prepared multi-antibodies functionalized MBs remain effective for bacterial capture after 1 day of storage at 4 °C. The multi-Abs@MBs successfully sensed E. coli and V . parahaemolyticus from fresh blood clam muscle tissue sample. The present protocol is expected to be applied in bacterial analysis of protein foods to guide their safe consumption.