scholarly journals A Comprehensive Evaluation of the Bruker Biotyper MS and Vitek MS Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry Systems for Identification of Yeasts, Part of the National China Hospital Invasive Fungal Surveillance Net (CHIF-NET) Study, 2012 to 2013

2016 ◽  
Vol 54 (5) ◽  
pp. 1376-1380 ◽  
Author(s):  
He Wang ◽  
Yan-Yan Fan ◽  
Timothy Kudinha ◽  
Zhi-Peng Xu ◽  
Meng Xiao ◽  
...  

Among the 2,683 yeast isolates representing 41 different species (25CandidaandCandida-related species and 16 non-Candidayeast species) collected in the National China Hospital Invasive Fungal Surveillance Net (CHIF-NET) program (2012 to 2013), the Bruker Biotyper MS matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) system exhibited significantly higher accuracy rates than the Vitek MS system for identification of all yeast isolates (98.8% versus 95.4%,P<0.001 by Pearson's chi-square test) and for allCandidaandCandida-related species isolates (99.4% versus 95.5%,P< 0.001).

2015 ◽  
Vol 54 (1) ◽  
pp. 226-229 ◽  
Author(s):  
Meng Xiao ◽  
Xin Fan ◽  
Xin-Xin Chen ◽  
He Wang ◽  
Li Zhang ◽  
...  

Forty-two putativeCryptococcus laurentiiisolates identified by the Vitek 2 system were collected in China. The gold standard, internal transcribed spacer (ITS) sequencing, confirmed that only two isolates were genuineC. laurentii. Bruker Biotyper matrix-assisted laser desorption ionization–time of flight mass spectrometry was able to identify theC. laurentiiisolates with an expanded custom database.


2016 ◽  
Vol 54 (4) ◽  
pp. 1130-1132 ◽  
Author(s):  
Valentijn A. Schweitzer ◽  
Alje P. van Dam ◽  
I Putu Yuda Hananta ◽  
Rob Schuurman ◽  
Johannes G. Kusters ◽  
...  

Identification ofNeisseria gonorrhoeaeby the Bruker matrix-assisted laser desorption ionization−time of flight mass spectrometry (MALDI-TOF MS) system may be affected by “B consistency categorization.” A supplementary database of 17N. gonorrhoeaemain spectra was constructed. Twelve of 64N. gonorrhoeaeidentifications were categorized with B consistency, which disappeared using the supplementary database. Database extension did not result in misidentification ofNeisseria meningitidis.


2016 ◽  
Vol 54 (12) ◽  
pp. 2982-2989 ◽  
Author(s):  
Liulin Luo ◽  
Weijia Liu ◽  
Bing Li ◽  
Mengling Li ◽  
Dongdong Huang ◽  
...  

This study was undertaken to evaluate the utility of matrix-assisted laser desorption ionization–time of flight mass spectrometry with the Vitek MS Plus system for identifying Mycobacterium abscessus subspecies in order to facilitate more rapid and appropriate therapy. A total of 175 clinical M. abscessus strains were identified by whole-genome sequencing analysis: 139 Mycobacterium abscessus subsp. abscessus and 36 Mycobacterium abscessus subsp. massiliense . The research-use-only (RUO) Saramis Knowledge Base database v.4.12 was modified accordingly by adding 40 M. abscessus subsp. abscessus and 19 M. abscessus subsp. massiliense reference spectra to construct subspecies SuperSpectra. A blind test, used to validate the remaining 116 isolates, yielded 99.1% ( n = 115) reliability and only 0.9% ( n = 1) error for subspecies identification. Among the two subspecies SuperSpectra, two specific peaks were found for M. abscessus subsp. abscessus and four specific peaks were found for M. abscessus subsp. massiliense . Our study is the first to report differential peaks 3,354.4 m / z and 6,711.1 m / z , which were specific for M. abscessus subsp. massiliense . Our research demonstrates the capacity of the Vitek MS RUO Saramis Knowledge Base database to identify M. abscessus at the subspecies level. Moreover, it validates the potential ease and accuracy with which it can be incorporated into the IVD system for the identification of M. abscessus subspecies.


2015 ◽  
Vol 53 (12) ◽  
pp. 3894-3896 ◽  
Author(s):  
Elenice R. A. Rodrigues ◽  
Alex G. Ferreira ◽  
Robson S. Leão ◽  
Cassiana C. F. Leite ◽  
Ana Paula Carvalho-Assef ◽  
...  

Molecular methodologies were used to identify 28Achromobacterspp. from patients with cystic fibrosis (CF). Multilocus sequence typing (MLST) identified 17Achromobacter xylosoxidansisolates (allblaOXA-114positive), nineAchromobacter ruhlandiiisolates (allblaOXA-114positive), oneAchromobacter dolensisolate, and oneAchromobacter insuavisisolate. All less common species were misidentified asA. xylosoxidansby matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS). Chronic colonization by clonally relatedA. ruhlandiiisolates was demonstrated.


2016 ◽  
Vol 55 (1) ◽  
pp. 97-100 ◽  
Author(s):  
Evgeny A. Idelevich ◽  
Barbara Grünastel ◽  
Karsten Becker

ABSTRACTCandidasepsis is a life-threatening condition with increasing prevalence. In this study, direct blood culturing on solid medium using a lysis-centrifugation procedure enabled successfulCandidaspecies identification by matrix-assisted laser desorption–ionization time of flight mass spectrometry on average 3.8 h (Sabouraud agar) or 7.4 h (chocolate agar) before the positivity signal for control samples in Bactec mycosis-IC/F or Bactec Plus aerobic/F bottles, respectively. Direct culturing on solid medium accelerated candidemia diagnostics compared to that with automated broth-based systems.


2017 ◽  
Vol 55 (7) ◽  
pp. 2255-2260 ◽  
Author(s):  
Carlos Ruiz de Alegría Puig ◽  
Lilian Pilares ◽  
Francesc Marco ◽  
Jordi Vila ◽  
Luis Martínez-Martínez ◽  
...  

ABSTRACTRhodococcus equicauses pyogranulomatous pneumonia in domesticated animals and immunocompromised humans.Dietziaspp. are environmental bacteria that have rarely been associated with human infections.R. equiandDietziaspp. are closely related actinomycetes. Phenotypic discrimination betweenR. equiandDietziaon the basis of their Gram stain morphology and colony appearance is problematic. Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) is a fast, reliable, and cost-effective method for identification of a wide variety of microorganisms. We have evaluated the performance of Bruker Biotyper versus that of Vitek MS for identification of a collection of 154 isolates identified at the source asR. equithat includes isolates belonging to the genusDietzia. PCR amplification of thechoEgene, encoding a cholesterol oxidase, and 16S rRNA sequencing were considered the reference methods forR. equiidentification. Biotyper identified 131 (85.1%) of the 154 isolates at the species level, and this figure increased to 152 (98.7%) when the species cutoff was reduced from a score of ≥2.000 to ≥1.750. Vitek MS correctly identified at the species level 130 (84.4%) isolates as long as bacteria were extracted with ethanol but only 35 (22.7%) isolates when samples were prepared by direct extraction from colonies. The two systems allowed differentiation betweenR. equiandDietziaspp., but identification of allDietziasp. isolates at the species level needed sequencing of the 16S rRNA gene.


2016 ◽  
Vol 54 (8) ◽  
pp. 2182-2186 ◽  
Author(s):  
Sue Sleiman ◽  
Catriona L. Halliday ◽  
Belinda Chapman ◽  
Mitchell Brown ◽  
Joanne Nitschke ◽  
...  

We developed an Australian database for the identification ofAspergillus,Scedosporium, andFusariumspecies (n= 28) by matrix-assisted laser desorption ionization−time of flight mass spectrometry (MALDI-TOF MS). In a challenge against 117 isolates, species identification significantly improved when the in-house-built database was combined with the Bruker Filamentous Fungi Library compared with that for the Bruker library alone (Aspergillus, 93% versus 69%;Fusarium, 84% versus 42%; andScedosporium, 94% versus 18%, respectively).


2018 ◽  
Vol 57 (2) ◽  
Author(s):  
Loïc Simon ◽  
Estelle Ughetto ◽  
Alice Gaudart ◽  
Nicolas Degand ◽  
Romain Lotte ◽  
...  

ABSTRACTMatrix-assisted laser desorption ionization–time of flight mass spectrometry is not widely used to identify bacteria directly from positive blood culture bottles (BCBs) because of overlong protocols. The objective of this work was to develop and evaluate a simple extraction protocol for reliable identification from BCBs. The 10-min protocol was applied over a 5-month period. Direct identifications on day 0 were compared with those obtained from colonies on day 1 [log(score) of ≥2]. We evaluated a range of seven log(score) thresholds on day 0 from 1.4 to 2.0 to find the lower confidence score that provides the higher percentage of direct identifications without loss of accuracy. With a log(score) threshold of ≥1.5 at day 0, our protocol allowed us to identify 80% of bacteria in 632 BCBs (96% ofEnterobacteriaceae, 95% ofStaphylococcus aureus, 92% of enterococci, and 62% of streptococci). At least one bacterial species of the mixture was identified in 77% of the polymicrobial samples. The rapidity and reliability of the protocol were factors in its adoption for routine use, allowing us to save up to 24 h in identifying 80% of the bacteria in the BCBs and, thus, to supply useful information to adapt antibiotic therapy when necessary. We currently provide reliable daily direct identifications of staphylococci, enterococci,Enterobacteriaceae,Pseudomonas aeruginosa,and beta-hemolytic streptococci.


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