In-house method for direct bacterial identification in positive blood culture broths using microfiltration, bead beating, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Rapid identification of bacterial pathogens facilitates earlier optimization of antibiotic treatment and reduces morbidity and mortality in sepsis patients. The aim of this research was to design an in-house chemical-free method for direct bacterial identification in positive blood culture (BC) broths and to compare the performance of this method with that of the commercial Sepsityper® kit. The overall species identification rates for the in-house and Sepsityper methods were 88.4% and 85.8%, respectively (n = 190). Among 146 facultative anaerobes, 92.5% and 95.9% were identified to the species level using the in-house and Sepsityper methods, respectively. For 32 anaerobic bacteria, the in-house method showed a higher species identification rate (75.0%) than the Sepsityper method (53.1%). The in-house method correctly identified more Bacteroides species (100.0%) than the Sepsityper method (18.2%). Our novel in-house method and the Sepsityper method showed a high accuracy for direct bacterial identification in positive BC broths using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.