Direct analysis of positive blood cultures using MALDI-TOF MS profiling and a fundamentally improved sample preparation technique

Pathology ◽  
2011 ◽  
Vol 43 ◽  
pp. S73-S74
Author(s):  
Guido Mix ◽  
Leith Fremlin ◽  
Thomas Maier ◽  
Beatrix Wegemann ◽  
Markus Kostrzewa
2017 ◽  
Vol 55 (5) ◽  
pp. 1437-1445 ◽  
Author(s):  
Maya Beganovic ◽  
Michael Costello ◽  
Sarah M. Wieczorkiewicz

ABSTRACT Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) decreases the time to organism identification and improves clinical and financial outcomes. The purpose of this study was to evaluate the impact of MALDI-TOF MS alone versus MALDI-TOF MS combined with real-time, pharmacist-driven, antimicrobial stewardship (AMS) intervention on patient outcomes. This single-center, pre-post, quasiexperimental study evaluated hospitalized patients with positive blood cultures identified via MALDI-TOF MS combined with prospective AMS intervention compared to a control cohort with MALDI-TOF MS identification without AMS intervention. AMS intervention included: real-time MALDI-TOF MS pharmacist notification and prospective AMS provider feedback. The primary outcome was the time to optimal therapy (TTOT). A total of 252 blood cultures, 126 in each group, were included in the final analysis. MALDI-TOF MS plus AMS intervention significantly reduced the overall TTOT (75.17 versus 43.06 h; P < 0.001), the Gram-positive contaminant TTOT (48.21 versus 11.75 h; P < 0.001), the Gram-negative infection (GNI) TTOT (71.83 versus 35.98 h; P < 0.001), and the overall hospital length of stay (LOS; 15.03 versus 9.02 days; P = 0.021). The TTOT for Gram-positive infection (GPI) was improved (64.04 versus 41.61 h; P = 0.082). For GPI, the hospital LOS (14.64 versus 10.31 days; P = 0.002) and length of antimicrobial therapy 24.30 versus 18.97 days; P = 0.018) were reduced. For GNI, the time to microbiologic clearance (51.13 versus 34.51 h; P < 0.001), the hospital LOS (15.40 versus 7.90 days; P = 0.027), and the intensive care unit LOS (5.55 versus 1.19 days; P = 0.035) were reduced. To achieve optimal outcomes, rapid identification with MALDI-TOF MS combined with real-time AMS intervention is more impactful than MALDI-TOF MS alone.


Author(s):  
Cledir Santos ◽  
Paula Galeano ◽  
Reginaldo Lima Neto ◽  
Manoel Marques Evangelista Oliveira ◽  
Nelson Lima

Abstract Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) is now used as a routine technique for the fast and reliable identification of fungi at the species level and, currently, it represents an important phenotypic methodology based on proteomic profiles. The main limitations to MALDI-TOF MS for fungal identification are related to sample quality (e.g. quality of biological material such as rigidity or pigmentation of cell walls), sample preparation (e.g. the myriad of sample preparation methodologies that deliver different data sets to different MALDI-TOF MS databases) and the databases themselves (e.g. the 'black-box' commercial databases). This chapter presents an overview and discussion of the use of MALDI-TOF MS for fungal identification. The major known limitations of the technique for fungal taxonomy, and how to overcome these, are also discussed.


2019 ◽  
Vol 3 (4) ◽  
pp. 255-259 ◽  
Author(s):  
Lindsay Y. Chun ◽  
Laura Dolle Molle ◽  
Olaf Schneewind ◽  
Dominique Missiakas ◽  
Kathleen G. Beavis ◽  
...  

Purpose:We report a case of a 72-year-old man with bleb-related endophthalmitis (BRE) whose vitreous samples were directly analyzed with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to rapidly identify the causative organism, whereas the results from conventional microbiological techniques were negative.Methods:We analyzed BRE vitreous samples with MALDI-TOF MS (Vitek MS, bioMérieux) for rapid pathogen identification without prior culture. Samples were also analyzed with standard microbiological methods.Results:Within 1 hour of sample acquisition, MALDI-TOF MS identified Gemella sanguinis from the undiluted vitreous sample from vitrectomy without prior culture with a confidence value of 99.7%. Gram stain and cultures from aqueous and vitreous samples were negative for 28 days after acquisition. The patient’s right-eye vision improved from hand motion to 20/50 2 months later.Conclusions:Our findings suggest that the direct analysis of intraocular samples with MALDI-TOF MS could be a novel, promising adjuvant method of rapid endophthalmitis diagnosis.


2007 ◽  
Vol 2007 (8) ◽  
pp. pdb.prot4618-pdb.prot4618
Author(s):  
L. J. Deterding ◽  
J. M. Cutalo ◽  
K. B. Tomer

Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3214
Author(s):  
Gabor Maasz ◽  
Zita Zrínyi ◽  
Istvan Fodor ◽  
Nóra Boross ◽  
Zoltán Vitál ◽  
...  

Knowledge of intraspecific variability of a certain species is essential for their long-term survival and for the development of conservation plans. Nowadays, molecular/genetic methods are the most frequently used for this purpose. Although, the Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) technique has become a promising alternative tool to specify intraspecific variability, there is a lack of information about the limitations of this method, and some methodological issues need to be resolved. Towards this goal, we tested the sensitivity of this method on an intraspecific level, using genetically identified individuals of a cryptic fish species complex collected from five distinct populations. Additionally, some methodologic issues, such as the effect of (1) delayed sample preparation, (2) clove oil anaesthetization, and (3) different tissue types (muscle, and brain) were investigated using the MS analysis results. Our results show that the delayed sample preparation has a fundamental effect on the result of MS analysis, while at the same time the clove oil did not affect the results considerably. Both the brain and muscle samples were usable for cryptic species identification, but in our opinion this method has limited applicability for population-level segregation. The application of MALDI-TOF MS to the exploitable toolkit of phylogenetic and taxonomic researches could be used to broaden conclusions.


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