Improving Septicemia Diagnostics: A Comparative Analysis of Direct and Post-Culture MALDI-TOF MS Methods for Bacterial Identification.

Abstract

Introduction: Bloodstream infections are serious conditions requiring precise bacterial identification for effective treatment. Traditional culture-based methods, while reliable, are time-consuming. The direct identification method by MALDI-TOF MS promises rapid and accurate identification directly from positive blood cultures.

Aim: To evaluate and compare the direct MALDI-TOF MS identification method for positive blood culture samples with the post-culture MALDI-TOF MS method, which is currently recognized as the gold standard in bacteriological identification.

Methods: during the study period, 324 positive blood culture samples received at the Central Laboratory of Bacteriology, Serology, and Hygiene of the IBN SINA Hospital Center in Rabat were included in the study. Each sample was processed for microorganism identification by MALDI-TOF MS using both direct and post-culture methods.

Results: The direct identification method by MALDI-TOF MS showed a lower overall identification success rate (64.8%) compared to the post-culture method (100%). However, it allowed for bacterial identification in less than one hour without the need for a sub-culturing step, highlighting the technique's potential to enhance the diagnostic process.

Conclusion: The direct identification method by MALDI-TOF MS has the potential to improve the speed of bacterial identification in positive blood cultures compared to the current gold standard of identification after culture. Despite its limitations, the direct method offers an opportunity to improve diagnosis and patient management, especially when combined with the standard method.