Rapid Automated Isolation and Concentration of Bacteria from Blood Samples

Abstract

Sepsis is a major global health challenge associated with high mortality rates, with approximately 50 million cases yearly and 13 million deaths. For every hour a patient with septic shock remains untreated, survival decreases by 8%. Challenges persist in the rapid isolation of bacterial pathogens from blood, leading to delays in microorganism identification and antimicrobial susceptibility testing. In this study, we report a centrifuge-based device for the automated isolation and concentration of bacteria from blood samples within 40 min. The device starts with 3 ml of blood or 7.5 ml of blood culture and yields 0.7 mL of optically clear sample with a more than three-fold increased bacterial concentration, rejecting 99.97 {+/-} 0.01% of red blood cells, 97 {+/-} 1% of white blood cells, and 94 {+/-} 4% of platelets. We successfully demonstrated how this process prepares blood culture samples for subsequent: sub-culturing from as low as 10 CFU/mL initial bacterial concentration; matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS)-based identification from 5 x 108 CFU/ml initial bacterial concentration; and microtrap-based detection within 1 h from 5 x 104 CFU/ml initial bacterial concentration. These results demonstrate the potential of this device to automate and accelerate the diagnostic pipeline for sepsis, enabling faster detection and identification of the causative microorganism.