Mass spectrometry in the clinical microbiology laboratory, part II: MALDI-TOF MS

2012 ◽  
Vol 34 (18) ◽  
pp. 143-147 ◽  
Author(s):  
Prasanna D. Khot ◽  
Mark A. Fisher
2015 ◽  
Vol 2015 ◽  
pp. 1-18 ◽  
Author(s):  
Kivanc Bilecen ◽  
Gorkem Yaman ◽  
Ugur Ciftci ◽  
Yahya Rauf Laleli

In clinical microbiology laboratories, routine microbial identification is mostly performed using culture based methodologies requiring 24 to 72 hours from culturing to identification. Matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) technology has been established as a cost effective, reliable, and faster alternative identification platform. In this study, we evaluated the reliability of the two available MALDI-TOF MS systems for their routine clinical level identification accuracy and efficiency in a clinical microbiology laboratory setting. A total of 1,341 routine phenotypically identified clinical bacterial and fungal isolates were selected and simultaneously analyzed using VITEK MS (bioMérieux, France) and Microflex LT (Bruker Diagnostics, Germany) MALDI-TOF MS systems. For any isolate that could not be identified with either of the systems and for any discordant result, 16S rDNA gene or ITS1/ITS2 sequencing was used. VITEK MS and Microflex LT correctly identified 1,303 (97.17%) and 1,298 (96.79%) isolates to the species level, respectively. In 114 (8.50%) isolates initial phenotypic identification was inaccurate. Both systems showed a similar identification efficiency and workflow robustness, and they were twice as more accurate compared to routine phenotypic identification in our sample pool. MALDITOF systems with their accuracy and robustness offer a good identification platform for routine clinical microbiology laboratories.


Anaerobe ◽  
2018 ◽  
Vol 54 ◽  
pp. 151-158 ◽  
Author(s):  
Peivern Fong ◽  
Michelle J. Francis ◽  
John F. Hamblin ◽  
Tony M. Korman ◽  
Maryza Graham

2013 ◽  
Vol 49 (4) ◽  
pp. 256-259 ◽  
Author(s):  
Marcelo Jenne Mimica ◽  
Marines Dalla Valle Martino ◽  
Jacyr Pasternak

2015 ◽  
Vol 61 (1) ◽  
pp. 100-111 ◽  
Author(s):  
Robin Patel

Abstract BACKGROUND First introduced into clinical microbiology laboratories in Europe, MALDI-TOF MS is being rapidly embraced by laboratories around the globe. Although it has multiple applications, its widespread adoption in clinical microbiology relates to its use as an inexpensive, easy, fast, and accurate method for identification of grown bacteria and fungi based on automated analysis of the mass distribution of bacterial proteins. CONTENT This review provides a historical perspective on this new technology. Modern applications in the clinical microbiology laboratory are reviewed with a focus on the most recent publications in the field. Identification of aerobic and anaerobic bacteria, mycobacteria, and fungi are discussed, as are applications for testing urine and positive blood culture bottles. The strengths and limitations of MALDI-TOF MS applications in clinical microbiology are also addressed. SUMMARY MALDI-TOF MS is a tool for rapid, accurate, and cost-effective identification of cultured bacteria and fungi in clinical microbiology. The technology is automated, high throughput, and applicable to a broad range of common as well as esoteric bacteria and fungi. MALDI-TOF MS is an incontrovertibly beneficial technology for the clinical microbiology laboratory.


Author(s):  
Arzu Akşit İlki ◽  
Sevim Özsoy ◽  
Gulşen Gelmez ◽  
Burak Aksu ◽  
Güner Söyletir

AbstractUrinary tract infections are one of the most common bacterial infections and rapid diagnosis of the infection is essential for appropriate antibiotic therapy. The goal of our study was to identify urinary pathogens directly by MALDI-TOF MS and to perform antibiotic susceptibility tests in order to shorten the period spent for culturing.Urine samples submitted for culture to the Clinical Microbiology Laboratory were enrolled in this study. Urine samples were screened for leukocyte and bacteria amount by flow cytometry. Samples with bacterial load of 106–107/mL were tested directly by MALDI-TOF MS and antibiotic susceptibility tests (AST) were performed.In total, 538 positive urine samples were evaluated in our study. MALDI-TOF MS identified the microorganism directly from the urine sample in 91.8% of these samples and the concordance rate of conventional identification and direct detection was 95.8% for Gram-negatives at the genus and species level. Escherichia coli (n:401) was the most frequently isolated microorganism, followed by Klebsiella pneumoniae (n:57). AST results were generated for 111 of these urine samples and the concordance was 90% and 87% for E. coli and K. pneumoniae, respectively.Our results showed that screening of urine samples with flow cytometry to detect positive samples and identification of uropathogens directly by MALDI-TOF MS with an accuracy of over 90% can be a suitable method particularly for Gram-negative bacteria in clinical microbiology laboratories.


2015 ◽  
Vol 68 (12) ◽  
pp. 1040-1042 ◽  
Author(s):  
Nita Fatania ◽  
Mark Fraser ◽  
Mike Savage ◽  
Jason Hart ◽  
Alireza Abdolrasouli

AimsPerformance of matrix-assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF MS) was compared in a side-by side-analysis with conventional phenotypic methods currently in use in our laboratory for identification of yeasts in a routine diagnostic setting.MethodsA diverse collection of 200 clinically important yeasts (19 species, five genera) were identified by both methods using standard protocols. Discordant or unreliable identifications were resolved by sequencing of the internal transcribed spacer region of the rRNA gene.ResultsMALDI-TOF and conventional methods were in agreement for 182 isolates (91%) with correct identification to species level. Eighteen discordant results (9%) were due to rarely encountered species, hence the difficulty in their identification using traditional phenotypic methods.ConclusionsMALDI-TOF MS enabled rapid, reliable and accurate identification of clinically important yeasts in a routine diagnostic microbiology laboratory. Isolates with rare, unusual or low probability identifications should be confirmed using robust molecular methods.


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