scholarly journals Comparative Analysis of PCR–Electrospray Ionization/Mass Spectrometry (MS) and MALDI-TOF/MS for the Identification of Bacteria and Yeast from Positive Blood Culture Bottles

2011 ◽  
Vol 57 (7) ◽  
pp. 1057-1067 ◽  
Author(s):  
Erin J Kaleta ◽  
Andrew E Clark ◽  
Abdessalam Cherkaoui ◽  
Vicki H Wysocki ◽  
Elizabeth L Ingram ◽  
...  
Keyword(s):  
Blood Culture ◽  
Diagnostic Accuracy ◽  
Bloodstream Infections ◽  
Rapid Identification ◽  
Blood Cultures ◽  
Reference Standard ◽  
Maldi Tof Ms ◽  
Esi Ms ◽  
Maldi Tof ◽  
Tof Ms

BACKGROUND Emerging technologies for rapid identification of microbes demonstrate a shift from traditional biochemical and molecular testing algorithms toward methods using mass spectrometry (MS) for the semiquantitative analysis of microbial proteins and genetic elements. This study was performed to assess the diagnostic accuracy of 2 such technologies, PCR–electrospray ionization (ESI)/MS and MALDI-TOF/MS, with respect to phenotypic and biochemical profiling as a reference standard method. A positive challenge set of blood culture bottles was used to compare PCR-ESI/MS and MALDI-TOF/MS performance on a matched set of samples. METHODS We performed characterization of bloodstream infections from blood cultures using the Ibis T5000 PCR-ESI/MS and the Bruker MALDI Biotyper 2.0 (MALDI-TOF/MS) platforms for microbial identification. Diagnostic accuracy was determined by independent comparison of each method to phenotypic and biochemical characterization with Vitek2 analysis as the reference standard identification. RESULTS The diagnostic accuracy, represented as positive agreement, at the genus level was 0.965 (0.930–0.984) for PCR-ESI/MS and 0.969 (0.935–0.987) for MALDI-TOF/MS, and at the species level was 0.952 (0.912–0.974) with PCR-ESI/MS and 0.943 (0.902–0.968) for MALDI-TOF/MS. No statistically significant difference was found between PCR-ESI/MS and MALDI-TOF/MS in the ability to rapidly identify microorganisms isolated from blood culture. CONCLUSIONS Our results demonstrate that PCR-ESI/MS and MALDI-TOF/MS are equivalent in their ability to characterize bloodstream infections with respect to the reference standard, and highlight key differences in the methods that allow for each method to have a unique niche as a tool for rapid identification of microbes in blood cultures.

scholarly journals Direct Rapid Identification from Positive Blood Cultures by MALDI-TOF MS: Specific Focus on Turnaround Times

2021 ◽  
Author(s):  
Hazan Zengin Canalp ◽  
Banu Bayraktar
Keyword(s):  
Blood Culture ◽  
Rapid Identification ◽  
Blood Cultures ◽  
Pathogen Identification ◽  
Short Term ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Solid Media ◽  
Time Required ◽  
Tof Ms

Using MALDI-TOF MS directly from blood culture bottles reduces the time required for pathogen identification, and the turnaround times for final identification have been compared with overnight incubation from solid media in previous studies. However, identification from a short incubation of agar plates has been increasingly accepted and successfully implemented in routine laboratories, but there is no data comparing direct MALDI-TOF MS with the short-term, incubated agar plates.

scholarly journals 55. Impact of Testing Methodology and Reporting on Time to Preferred Antibiotic Therapy in Extended Spectrum Beta-Lactamase producing Enterobacteriaceae (ESBL-E) Bloodstream Infections

2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S147-S147
Author(s):  
Hanh Bui ◽  
Frank Tverdek ◽  
Stephanie Carnes ◽  
Jeannie D Chan ◽  
Andrew Bryan ◽  
...  
Keyword(s):  
Blood Culture ◽  
Medical Center ◽  
Bloodstream Infections ◽  
Blood Cultures ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Definitive Therapy ◽  
Significant Difference ◽  
Carbapenem Antibiotic ◽  
Tof Ms

Abstract Background Harborview Medical Center (HMC) identifies organisms and an ESBL genotype (CTX-M) via Verigene® Gram-Negative Blood Culture Nucleic Acid Test (BC-GN). University of Washington-Montlake (UWML) uses matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) for organism identification directly from positive blood cultures and ceftriaxone results by Kirby Bauer disk diffusion (KB) are reported 18 hours later. No ESBL comment is reported at UWML. We aimed to determine whether the methodology in identification and reporting of ESBL-E from blood cultures between two hospitals has an impact on time to preferred therapy with a carbapenem antibiotic. Methods Retrospective observational study conducted at UWML and HMC in Seattle, WA between 1/10/2015 and 9/15/2020. Adult patients were eligible if they had ≥1 positive blood culture with an Enterobacteriaceae isolate resistant to ceftriaxone and were on antibiotic treatment. The primary outcome was the difference in time to preferred definitive therapy with a carbapenem antibiotic in patients an ESBL-E bloodstream infection (BSI) identified by Verigene® vs. MALDI-TOF MS/KB. Results A total of 199 patients were screened; 67 were included for UWML and 68 at HMC. The average time to initiation of a carbapenem antibiotic was 42 ±26.5 hours at UWML and 28 ±19.7 hours at HMC. A t-test detected a difference in time to preferred therapy between a Verigene® vs. MALDI-TOF MS/KB tested ESBL-E BSI [95% confidence interval (CI), 5.3-22.9]. The hazard ratio to carbapenem initiation for HMC is 1.73643 [95% CI, 1.1405-2.644]. Conclusion A statistically significant difference in time to preferred definitive therapy among patients with an ESBL-E BSI processed by Verigene® was found compared to MALDI-TOF MS. The results suggest standardization in protocols between the UWML and HMC hospitals is warranted. Disclosures Andrew Bryan, MD, PhD, Shionogi Inc. (Grant/Research Support)

scholarly journals Rapid Identification of Microorganisms from Positive Blood Culture by MALDI-TOF MS After Short-Term Incubation on Solid Medium

2016 ◽  
Vol 74 (1) ◽  
pp. 97-102 ◽  
Author(s):  
Antonio Curtoni ◽  
Raffaella Cipriani ◽  
Elisa Simona Marra ◽  
Anna Maria Barbui ◽  
Rossana Cavallo ◽  
...  
Keyword(s):  
Blood Culture ◽  
Positive Blood Culture ◽  
Solid Medium ◽  
Rapid Identification ◽  
Short Term ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

Rapid identification of bacteria from bioMerieux BacT/ALERT blood culture bottles by MALDI-TOF MS

2013 ◽  
Vol 70 (4) ◽  
pp. 149-155 ◽  
Author(s):  
J.D. Haigh ◽  
I.M. Green ◽  
D. Ball ◽  
M. Eydmann ◽  
M. Millar ◽  
...  
Keyword(s):  
Blood Culture ◽  
Rapid Identification ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Identification Of Bacteria ◽  
Tof Ms

scholarly journals A Prospective Evaluation of Two Rapid Phenotypical Antimicrobial Susceptibility Technologies for the Diagnostic Stewardship of Sepsis

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Cesira Giordano ◽  
Elena Piccoli ◽  
Veronica Brucculeri ◽  
Simona Barnini
Keyword(s):  
Antimicrobial Susceptibility ◽  
Multidrug Resistant ◽  
Rapid Identification ◽  
Blood Cultures ◽  
Gram Positive ◽  
Gram Negative ◽  
Maldi Tof Ms ◽  
Gram Positive Bacteria ◽  
Maldi Tof ◽  
Tof Ms

Rapid identification of bloodstream pathogens by MALDI-TOF MS and the recently introduced rapid antimicrobial susceptibility testing (rAST) directly from positive blood cultures allow clinicians to promptly achieve a targeted therapy, especially for multidrug resistant microorganisms. In the present study, we propose a comparison between phenotypical rASTs performed in light-scattering technology (Alfred 60AST, Alifax®) and fluorescencein situhybridization (Pheno™, Accelerate) directly from positive blood cultures, providing results in 4–7 hours. Blood samples from 67 patients admitted to the Azienda Ospedaliero-Universitaria Pisana were analyzed. After the direct MALDI-TOF MS identification, the rAST was performed at the same time both on Alfred 60AST and Pheno. Alfred 60AST provided qualitative results, interpreted in terms of clinical categories (SIR). Pheno provided identification and MIC values for each antibiotic tested. Results were compared to the broth microdilution assay (SensiTitre™, Thermo Fisher Scientific), according to EUCAST rules. Using Alfred 60AST, an agreement was reached, 91.1% for Gram-negative and 95.7% for Gram-positive bacteria, while using Pheno, the agreement was 90.6% for Gram-negative and 100% for Gram-positive bacteria. Both methods provided reliable results; Alfred 60AST combined with MALDI-TOF MS proved itself faster and cheaper. Pheno provided identification and MIC determination in a single test and, although more expensive, may be useful whenever MIC value is necessary and where MALDI-TOF MS is not present.

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