Performance of two MALDI-TOF MS systems for the identification of yeasts isolated from bloodstream infections and cerebrospinal fluids using a time-saving direct transfer protocol

2013 ◽  
Vol 203 (2) ◽  
pp. 93-99 ◽  
Author(s):  
Axel Hamprecht ◽  
Sara Christ ◽  
Tanja Oestreicher ◽  
Georg Plum ◽  
Volkhard A. J. Kempf ◽  
...  
Keyword(s):  
Bloodstream Infections ◽  
Direct Transfer ◽  
Time Saving ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms ◽  
Transfer Protocol

scholarly journals Identification of the ‘Streptococcus anginosus group’ by matrix-assisted laser desorption ionization – time-of-flight mass spectrometry

2014 ◽  
Vol 63 (9) ◽  
pp. 1143-1147 ◽  
Author(s):  
Katherine Woods ◽  
David Beighton ◽  
John L. Klein
Keyword(s):  
Species Level ◽  
Direct Transfer ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Streptococcus Anginosus ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Transfer Method ◽  
Tof Ms

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) provides rapid, accurate and cost-effective identification of a range of bacteria and is rapidly changing the face of routine diagnostic microbiology. However, certain groups of bacteria, for example streptococci (in particular viridans or non-haemolytic streptococci), are less reliably identified by this method. We studied the performance of MALDI-TOF MS for identification of the ‘Streptococcus anginosus group’ (SAG) to species level. In total, 116 stored bacteraemia isolates identified by conventional methods as belonging to the SAG were analysed by MALDI-TOF MS. Partial 16S rRNA gene sequencing, supplemented with sialidase activity testing, was performed on all isolates to provide ‘gold standard’ identification against which to compare MALDI-TOF MS performance. Overall, 100 % of isolates were correctly identified to the genus level and 93.1 % to the species level by MALDI-TOF MS. However, only 77.6 % were correctly identified to the genus level and 59.5 % to the species level by a MALDI-TOF MS direct transfer method alone. Use of a rapid in situ extraction method significantly improved identification rates when compared with the direct transfer method (P<0.001). We recommend routine use of this method to reduce the number of time-consuming full extractions required for identification of this group of bacteria by MALDI-TOF MS in the routine diagnostic laboratory. Only 22 % (1/9) of Streptococcus intermedius isolates were reliably identified by MALDI-TOF MS to the species level, even after full extraction. MALDI-TOF MS reliably identifies S. anginosus and Streptococcus constellatus to the species level but does not reliably identify S. intermedius.

scholarly journals MALDI-TOF MS in Adult Inpatients with Bloodstream Infections: Pre- and Post-intervention Study

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S626-S626 ◽  
Author(s):  
Salman Khan ◽  
Dallas Dunn ◽  
Gargi Patel ◽  
Patricia Saunders-Hao ◽  
Meenakshi Rana ◽  
...  
Keyword(s):  
Intervention Study ◽  
Bloodstream Infections ◽  
Post Intervention ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

scholarly journals Application of MALDI-TOF MS to assess clinical characteristics, risk factors, and outcomes associated with anaerobic bloodstream infection: a retrospective observational study

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Tsuyoshi Watanabe ◽  
Yuki Hara ◽  
Yusuke Yoshimi ◽  
Waka Yokoyama-kokuryo ◽  
Yoshiro Fujita ◽  
...  
Keyword(s):  
Risk Factors ◽  
Hospital Mortality ◽  
Multivariate Logistic Regression Analysis ◽  
Bloodstream Infections ◽  
Gram Positive ◽  
Accurate Identification ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Independent Risk Factors ◽  
Tof Ms

Abstract Background Correctly identifying anaerobic bloodstream infections (BSIs) is difficult. However, a new technique, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), enables more accurate identification and appropriate treatment. Anaerobic BSIs identified by MALDI-TOF MS were retrospectively analyzed to determine the clinical and microbiological features and patient outcomes based on the anaerobic genera or group. Methods Medical records of patients with anaerobic BSIs were used to conduct a single-center retrospective cohort study from January 2016 to December 2020 in Nagoya, Japan. Multivariate logistic regression analysis was performed to determine the independent risk factors for in-hospital mortality. Results Of the 215 patients with anaerobic BSIs, 31 had multiple anaerobic organisms in the blood culture, including 264 total episodes of anaerobic BSIs. Bacteroides spp. were isolated the most (n = 74), followed by gram-positive non-spore-forming bacilli (n = 57), Clostridium spp. (n = 52), gram-positive anaerobic cocci (GPAC) (n = 27), and gram-negative cocci (n = 7). The median patient age was 76 years; 56.7% were male. The most common focal infection site was intra-abdominal (36.7%). The in-hospital mortality caused by anaerobic BSIs was 21.3%, and was highest with Clostridium spp. (36.5%) and lowest with GPAC (3.7%). Age, solid tumors, and Clostridium spp. were independent risk factors for in-hospital mortality. Conclusions We identified current anaerobic BSI trends using MALDI-TOF MS and reported that mortality in patients with anaerobic BSIs patients was highest with Clostridium spp. infections.

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 A new culture-based method for rapid identification of microorganisms in polymicrobial blood cultures by MALDI-TOF MS

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Walter Florio ◽  
Susanna Cappellini ◽  
Cesira Giordano ◽  
Alessandra Vecchione ◽  
Emilia Ghelardi ◽  
...  
Keyword(s):  
Rapid Identification ◽  
Blood Cultures ◽  
Time Saving ◽  
Simple Method ◽  
Maldi Tof Ms ◽  
Microbial Identification ◽  
Microbial Species ◽  
Maldi Tof ◽  
Identification Of Bacteria ◽  
Tof Ms

Abstract Background The application of matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry (MS) to microbial identification has allowed the development of rapid methods for identification of microorganisms directly in positive, blood cultures (BCs). These methods can yield accurate results for monomicrobial BCs, but often fail to identify multiple microorganisms in polymicrobial BCs. The present study was aimed at establishing a rapid and simple method for identification of bacteria and yeast in polymicrobial BCs from patients with bloodstream infection. Results The rapid method herein proposed is based on short-term culture in liquid media allowing selective growth of microorganisms recovered from polymicrobial BCs, followed by rapid identification by MALDI-TOF MS. To evaluate the accuracy of this method, 56 polymicrobial BCs were comparatively analyzed with the rapid and routine methods. The results showed concordant identification for both microbial species in 43/50 (86%) BCs containing two different microorganisms, and for two microbial species in six BCs containing more than two different species. Overall, 102/119 (85.7%) microorganisms were concordantly identified by the rapid and routine methods using a cut-off value of 1.700 for valid identification. The mean time to identification after BC positivity was about 4.2 h for streptococci/enterococci, 8.7 h for staphylococci, 11.1 h for Gram-negative bacteria, and 14.4 h for yeast, allowing a significant time saving compared to the routine method. Conclusions The proposed method allowed rapid and reliable microbial identification in polymicrobial BCs, and could provide clinicians with timely, useful information to streamline empirical antimicrobial therapy in critically ill patients.

scholarly journals Comparison of Accelerate PhenoTest™ BC Kit vs. MALDI-TOF MS/VITEK®2 System for the Rapid Identification and Antimicrobial Susceptibility Testing of Gram-negative Bacilli Causing Bloodstream Infections

2019 ◽  
Author(s):  
William Stokes ◽  
Lorraine Campbell ◽  
Johann Pitout ◽  
John Conly ◽  
Deirdre Church ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Bloodstream Infections ◽  
Antimicrobial Susceptibility Testing ◽  
Clinical Samples ◽  
Gram Negative ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Conventional Methods ◽  
Tof Ms

Abstract Introduction: Our laboratory uses MALDI-TOF MS (MALDI) and the VITEK®2 system (DV2) directly from positive blood cultures (BC) for organism identification (ID) and antimicrobial susceptibility testing (AST). Our objective was to compare direct MALDI/DV2 to a commercial BC ID/AST platform, the Accelerate Pheno™ system, in the ID/AST of clinical and seeded BC positive for Gram-negative bacilli (GNB). Methods: BC positive for GNB were collected over a three month period and tested using AXDX, direct MALDI/DV2, and compared to conventional methods. A subset of sterile BC were seeded with multi-drug resistant GNB. Discrepancies in very major errors (VME) and major errors (ME) were confirmed with broth microdilution. Results: A total of 29 clinical samples and 35 seeded samples were analyzed. Direct MALDI had a higher ID failure rate (31.0%) compared to AXDX (3.4%) [p<0.001]. Time to ID/AST was 1.5/6.9 hours, 5.8/16.5 hours and 21.6/33.0 hours for AXDX, direct MALDI/DV2 and conventional methods, respectively (p<0.001). For clinical samples, AXDX and DV2 had essential agreement (EA)/categorical agreement (CA) >96%. For seeded samples, AXDX had EA, CA, VME, ME and mE of 93.2%, 89.0%, 2.2%, 0%, and 9.2%, respectively. AXDX had a large number of non-reports (6.1%), stemming from meropenem testing. DV2 had EA, CA, VME, ME and mE of 97.5%, 94.7%, 1.3%, 0%, and 4.4%, respectively. Conclusions: AXDX had fewer ID failures and more rapid ID/AST results. Direct MALDI/DV2 and AXDX both had high agreement for clinical samples but direct MALDI/DV2 had higher agreement when challenged with MDR GNB.

Fast identification of dermatophytes by MALDI-TOF/MS using direct transfer of fungal cells on ground steel target plates

Mycoses ◽  
2018 ◽  
Vol 61 (9) ◽  
pp. 691-697 ◽  
Author(s):  
Keith C. da Cunha ◽  
Arnaud Riat ◽  
Anne-Cecile Normand ◽  
Philipp P. Bosshard ◽  
Margarete T. G. de Almeida ◽  
...  
Keyword(s):  
Direct Transfer ◽  
Maldi Tof Ms ◽  
Fast Identification ◽  
Maldi Tof ◽  
Steel Target ◽  
Tof Ms
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