Authors: G A March–Rosselló M F Muñoz–Moreno M C GarcíaLoygorri–Jordán de Urriés M A Bratos–Pérez
Publish Date: 2012/12/30
Volume: 32, Issue: 5, Pages: 699-704
Abstract
Matrixassisted laser desorption/ionization–timeofflight mass spectrometry MALDITOF is a widely used tool in clinical microbiology for rapidly identifying microorganisms This technique can be applied directly on positive blood cultures without the need for its culturing thereby reducing the time required for microbiological diagnosis The present study proposes an innovative identification protocol applied to positive blood culture bottles using MALDITOF We have processed 100 positive blood culture bottles of which 36 of 37 Gramnegative bacteria 973 were correctly identified directly with 100 of Enterobacteriaceae and other Gramnegative rods and 875 of nonfermenting Gramnegative rods We also correctly identified directly 62 of 63 of Grampositive bacteria 984 with 100 of Streptococcus Enterococcus and Grampositive bacilli and 98 of Staphylococcus Applying the differential centrifugation protocol at the moment the automatic blood culture incubation system gives a positive reading together with the proposed validation criterion offers 98 sensitivity 95 confidence interval 952–100 The MALDITOF system thus provides a rapid and reliable system for identifying microorganisms from blood culture growth bottles
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