Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF) directly from positive blood culture flasks allows rapid identification of bloodstream infections in immunosuppressed hosts. Issue 3 (19th May 2015)

• Record Type: Journal Article
• Authors: Egli, A.; Osthoff, M.; Goldenberger, D.; Halter, J.; Schaub, S.; Steiger, J.; Weisser, M.; Frei, R.
• Is Part Of: Transplant infectious disease. Volume 17:Issue 3(2015)
• Page Start: 481
• Page End: 487
• Publication Date: 2015-05-19
• Subjects: Transplantation of organs, tissues, etc -- Complications -- Periodicals; Communicable diseases -- Periodicals; Infection -- Periodicals; 617.01
• DOI: 10.1111/tid.12373
• Languages: English
• ISSNs: 1398-2273

Abstract

<abstract abstract-type="main" id="tid12373-abs-0001"> <title>Abstract</title> <sec id="tid12373-sec-0001" sec-type="section"> <title>Introduction</title> <p>In immunosuppressed hosts, rapid identification of microorganisms of bloodstream infections is crucial to ensuring effective antimicrobial therapy. Conventional culture requires up to 72 h from sample collection to pathogen identification.</p> </sec> <sec id="tid12373-sec-0002" sec-type="section"> <title>Methods</title> <p>We used the SepsiTyper Kit and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF; Microflex, Bruker) directly from positive blood culture (BacT/ALERT 3D, FN/FA vials; bioMérieux) in comparison to standard culture methodology (VITEK 2; bioMérieux) for species identification.</p> </sec> <sec id="tid12373-sec-0003" sec-type="section"> <title>Results</title> <p>A total of 62 consecutive positive blood cultures from immunosuppressed patients (solid organ or hematopoietic transplant recipients, or with febrile neutropenia) were analyzed. Culture yielded gram‐negative bacteria (GNB) in 27/62 (43.5%) and gram‐positive (GPB) in 35/62 (56.5%) vials. For GNB, the predominant species identified by MALDI‐TOF and confirmed by VITEK were <italic>Escherichia coli</italic> (16/16 correctly identified) and <italic>Enterobacter cloacae</italic> (4/4), with a sensitivity and specificity of 92.6% and 100%, respectively. For GPB, predominant species were <italic>Staphylococcus aureus</italic> (3/3), coagulase‐negative staphylococci (12/24), and <italic>Enterococcus faecium</italic> (6/6) with a sensitivity of 100%, 60%, and 100%, respectively. The median time from blood collection to species identification was 27.4 h with MALDI‐TOF identification and 46.6 h with conventional methodology.</p> </sec> <sec id="tid12373-sec-0004" sec-type="section"> <title>Conclusion</title> <p>Using MALDI‐TOF directly from positive blood cultures allowed a shorter time to identification with high sensitivity and specificity in immunosuppressed patients.</p> </sec> </abstract>