scholarly journals Comparison of the Vitek MS and Bruker Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry Systems for Identification of Chryseobacterium Isolates from Clinical Specimens and Report of Uncommon Chryseobacterium Infections in Humans

2018 ◽  
Vol 56 (11) ◽  
Author(s):  
Jiun-Nong Lin ◽  
Shih-Hua Teng ◽  
Chung-Hsu Lai ◽  
Chih-Hui Yang ◽  
Yi-Han Huang ◽  
...  

ABSTRACT Matrix-assisted laser desorption ionization–time of flight mass spectrometry is becoming more popular and is replacing traditional identification methods in the clinical microbiology laboratory. We aimed to compare the Vitek mass spectrometry (MS) and Bruker Biotyper systems for the identification of Chryseobacterium isolated from clinical specimens and to report uncommon Chryseobacterium infections in humans. The microbial database from a hospital was searched for records between 2005 and 2016 to identify cultures that yielded Chryseobacterium. Species identification by the Vitek MS and Bruker Biotyper systems was compared to identification by 16S rRNA gene sequencing. Over the study period, 140 Chryseobacterium isolates were included. Based on 16S rRNA gene sequencing, 78 isolates were C. indologenes, 39 were C. gleum, 12 were uncommon Chryseobacterium species (C. arthrosphaerae, C. culicis, C. cucumeris, C. bernardetii, C. artocarpi, and C. daecheongense), and the remaining 11 isolates were only identified at the genus level. The Vitek MS and Bruker Biotyper systems correctly identified 98.7% and 100% of C. indologenes isolates, respectively. While the Bruker Biotyper accurately identified 100% of C. gleum isolates, the Vitek MS system correctly identified only 2.6% of isolates from this species. None of the uncommon Chryseobacterium species were successfully identified by either of these two systems. The overall accuracies of Chryseobacterium identification at the species level by the Vitek MS and Bruker Biotyper systems were 60.5% and 90.7%, respectively. An upgrade and correction of the Vitek MS and Bruker Biotyper databases is recommended to correctly identify Chryseobacterium species.

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).


2019 ◽  
Vol 43 (3) ◽  
pp. 157-162
Author(s):  
Gülşen Hasçelik ◽  
Markus Kostrzewa ◽  
Hamit Kaan Müştak ◽  
Celalettin Uner ◽  
Kadir Serdar Diker

Abstract Background The routine identification to the species level of Nocardia genus by conventional methods is a fastidious and time-consuming process owing to the limited biochemical reactivity of these microorganisms, often requiring 1 or more days to complete identification. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) is a new technology for definitive and rapid species identification. Methods We evaluated the MALDI-TOF MS for the identification of 44 clinical isolates of Nocardia species in comparison to 16S ribosomal RNA (rRNA) gene sequencing. Nocardia isolates were identified by microbiological examination, phenotypical tests and MALDI-TOF MS and the results were compared by 16S rRNA gene sequencing. Results Of the 44 Nocardia strains, the identification of 28 isolates was determined with MALDI Biotyper database. According to this, 16 isolates (57.1%) of the strain log scores were ≥2. Two (7.1%) were identified to the species level (log scores of ≥2) as Nocardia otitidiscaviarum. The addition of a newly established Nocardia database (16 new Nocardia strains included to the original database) did significantly improve the scores. The results were 43 (97.7%) correct identification to the species level (log scores of ≥2). Conclusions This study showed that the identification of clinical Nocardia isolates by the Bruker MALDI Biotyper is highly reliable, whereas identification rates are generally lower than those for some Gram-negative bacteria and Gram-positive cocci. Based on our data, the identification rates can be improved by validated new database entries and the results can be confirmed with nucleic acid sequence analysis.


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.


2015 ◽  
Vol 53 (10) ◽  
pp. 3380-3383 ◽  
Author(s):  
M.-C. Domingo ◽  
C. Yansouni ◽  
C. Gaudreau ◽  
F. Lamothe ◽  
S. Lévesque ◽  
...  

Bacteremia due toCloacibacillusspecies is poorly described. We present three cases involving eitherCloacibacillusevryensisorCloacibacillusporcorum. The isolates were identified by 16S rRNA gene sequencing and were susceptible to antibiotics commonly used for anaerobic infections. The clinical significance of these organisms as potential emerging pathogens is discussed.


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.


2013 ◽  
Vol 63 (Pt_6) ◽  
pp. 2146-2154 ◽  
Author(s):  
Kathryn Bernard ◽  
Ana Luisa Pacheco ◽  
Ian Cunningham ◽  
Navdeep Gill ◽  
Tamara Burdz ◽  
...  

Corynebacterium propinquum is a Gram-positive rod occasionally recovered from clinical infections which, according to 16S rRNA gene sequencing, is most closely related (>99 % sequence similarity) to Corynebacterium pseudodiphtheriticum . The two species are very similar biochemically, commonly differentiated by a single test, the detection of urease, where strains of C. propinquum are described as being urease-non-producing and strains of C. pseudodiphtheriticum are described as urease-producing. In this study, historical and contemporary strains of C. propinquum and C. pseudodiphtheriticum from this laboratory were definitively characterized, which included use of rpoB sequencing. Urease-producing strains of C. propinquum as well as typical urease-non-producing isolates were identified after rpoB sequencing, with six of these being originally identified as C. pseudodiphtheriticum . Based on these observations, we propose emendation of the description of C. propinquum to include strains which produce urease. MALDI-TOF analysis may be a useful tool to differentiate these taxa. Existing commercial databases should be updated to include urease-positive strains of C. propinquum .


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.


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