Validation of short culture method for rapid bacterial identification of blood cultures via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Abstract

Abstract Background Development of rapid bacterial identification from blood cultures has been an area of intense study in diagnostic microbiology. Shortened turnaround time coupled with antimicrobial stewardship interventions have been shown to improve patient outcomes and decrease healthcare-associated costs. Objectives We report the validation of a short incubation method for Gram-positive and Gram-negative bacterial identification utilizing MALDI-TOF MS without additional instrumentation, processing or cost compared with current practice. Methods Prospective, observational, single-centre study in a quaternary care academic hospital encompassing 376 blood cultures subjected to bacterial identification after short incubation periods of 3–4 and 6–8 h. Results There was 97.5% species-level identification agreement with tests undertaken after 3–4 h incubation with 83.6% isolates identified, and 99.7% species-level identification agreement after 6–8 h incubation with 96.7% isolates identified. Conclusions The short incubation method provides a rapid MALDI-TOF MS bacterial identification method, reducing turnaround time by 10–18 h compared with standard practice without additional cost, processing or instrumentation.