Direct identification of microorganisms from positive blood cultures using the lysis-filtration technique and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS): A multicentre study
Farina C.,Microbiology Laboratories Of Ao Papa Giovanni Xxiii |
Arena F.,University of Siena |
Casprini P.,Local Health Authority 4 |
Cichero P.,IRCCS San Raffaele Hospital |
And 12 more authors.
New Microbiologica | Year: 2015
Microbial identification from blood cultures is essential to institute optimal antibiotic therapy and improve survival possibilities. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been successfully applied to identify bacteria and yeasts from positive blood cultures broths. The aim of this multicentre study was to evaluate the reliability of the lysis-filtration technique associated with MALDI-TOF MS to directly identify microorganisms from 765 positive blood cultures collected in six Italian hospitals. Overall, 675/765 (78.1%) blood isolates were correctly identified at the species level, with significant differences between Gram-negative and Gram-positive bacteria (92.6%, and 69.8%, respectively). Some difficulties arise in identifying Streptococcus pneumoniae, Staphylococcus aureus, yeasts and anaerobes. The lysis-filtration protocol is a suitable procedure in terms of performance in identifying microorganisms, but it is quite expensive and technically time-consuming since the time of filtration is not regular for all the samples. The application of the MALDI-TOF MS technique to the direct microbial identification from positive blood cultures is a very promising approach, even if more experience must be gained to minimize errors and costs.