The Brazilian Journal of Infectious Diseases The Brazilian Journal of Infectious Diseases
Braz J Infect Dis 2017;21:339-42 - Vol. 21 Num.3 DOI: 10.1016/j.bjid.2017.03.007
Brief communication
Direct identification from positive blood broth culture by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS)
Maria Goreth Barberino, Marcio de Oliveira Silva, , Ana Carolina Palmeiras Arraes, Luís Cláudio Correia, Ana Verena Mendes
Hospital São Rafael, Salvador, BA, Brazil
Received 23 June 2016, Accepted 14 March 2017
Abstract

Bloodstream infections (BSIs) are among the most concerning bacterial infections. They are one of the leading causes of morbidity and mortality, and occur in 30–70% of critical care patients. The prompt identification of the causative microorganism can help choosing the appropriate antimicrobial therapy that will lead to better clinical outcomes. Blood culture is one of the most relevant tests for microbiological diagnosis of bacterial infections. The introduction of the MALDI-TOF microbiological diagnosis significantly decreased the time of identifying microorganisms. However, it depends on the growth on solid culture medium. In this study, 538 bottles of positive blood cultures were evaluated to test the accuracy of an in house modified protocol. The study sample consisted of 198 Gram-negative and 350 Gram-positive bacteria. In all, 460 (83.94%) species were identified based on the direct plate findings. The protocol allowed the identification of 185/198 (93.43%) of the Gram-negative bacteria, including aerobes, anaerobes, and non-fermenters, and 275/350 (78.85%) of the Gram-positive bacteria. The proposed method has the potential to provide accurate results in comparison to the traditional method with the potential to reduce the turnaround time for the results and optimize antimicrobial therapy in BSI.

Keywords
MALDI-TOF, Blood culture, Bacterial identification
Braz J Infect Dis 2017;21:339-42 - Vol. 21 Num.3 DOI: 10.1016/j.bjid.2017.03.007