Identification of Gram-positive anaerobic cocci by MALDI-TOF mass spectrometry

Veloo, Alida; Erhard, Marcel; Welker, Martin; Welling, Gjalt W.; Degener, John E.

doi:10.1016/j.syapm.2010.11.005

Cited by 76 publications

(49 citation statements)

References 20 publications

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“…In addition, the available database of the Bruker MS needs to be optimized for routine identification of anaerobes, as some organisms could not be identified by this system (Veloo et al, 2011a(Veloo et al, , 2011c. The Bruker MS has been evaluated for identification of organisms directly from blood culture but currently does not provide data about antimicrobial susceptibility patterns.…”

Section: Discussionmentioning

confidence: 99%

Comparison of two matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry methods and API 20AN for identification of clinically relevant anaerobic bacteria

Jamal

Shahin

Rotimi

2013

Journal of Medical Microbiology

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Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) is suitable for high-throughput and rapid microbial diagnosis at relatively low cost and can be considered an alternative to conventional biochemical and molecular identification systems in clinical microbiological laboratories, including anaerobe laboratories. Two commercially available MALDI-TOF MS systems, Bruker Microflex MS and bioMé rieux VITEK MS, were evaluated for the identification of 274 isolates of clinically significant anaerobic bacteria recovered from routine cultures of clinical specimens in parallel with blinded comparison with conventional biochemical (API 20AN) or molecular methods. All were recovered cultures obtained from patients attending the Mubarak Al Kabir Hospital, Kuwait, during a 6 month period. Discrepant results after two attempts at direct colony testing had failed to provide acceptable MALDI-TOF identification were resolved by gold-standard 16S gene sequencing. The VITEK MS gave high-confidence identification of the 274 isolates, all of which were correctly identified. The Bruker Microflex MS system also gave high-confidence identification for 272 of the 274. After discrepancy testing, the Bruker MS results agreed with biochemical or molecular methods for 89.1 % of the isolates at species level and 10.2 % at genus level (0.72 % were misidentified). The level of agreement with the VITEK MS was 100 % at both species and genus level; no isolates were misidentified. Our data suggest that implementation of MALDI-TOF MS as a first step for identification will shorten the turnaround time and reduce the cost in the anaerobe laboratory.

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Section: Discussionmentioning

confidence: 99%

Comparison of two matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry methods and API 20AN for identification of clinically relevant anaerobic bacteria

Jamal

Shahin

Rotimi

2013

Journal of Medical Microbiology

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“…The efficacy and utility of MALDI-TOF analysis for the identification of clinical isolates have been thoroughly demonstrated in recent literature (3,(5)(6)(7)(8)(9)(13)(14)(15)(16)(17)(18)(19). Some studies suggest that MALDI-TOF analysis, in addition to being a rapid method of initial bacterial identification, could serve as a cost-effective substitute to sequencing as a reference method (3).…”

Section: Discussionmentioning

confidence: 99%

“…Molecular methods provide reliable results, though many are expensive to perform, time-consuming, and technically demanding (6). Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has recently emerged as a rapid, accurate, and cost-effective method of identification, applicable to a wide range of bacterial isolates (9,12,13,16,17,19).A major benefit of MALDI-TOF technology is the ability to obtain identifications using a single colony, eliminating the need for subculture and further incubation. To identify most isolates, a single colony can be picked from solid culture media using a swab or toothpick and smeared directly onto a polished steel target plate for identification (direct method) (1, 9, 14, 17, 18).…”

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confidence: 99%

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confidence: 99%

“…To identify most isolates, a single colony can be picked from solid culture media using a swab or toothpick and smeared directly onto a polished steel target plate for identification (direct method) (1,9,14,17,18). Alternatively, isolates with formidable cell walls or those that produce excess exopolysaccharide matrix (i.e., mucoid pseudomonads) may require processing through a short (approximately 5-min) formic acid-acetonitrile extraction and centrifugation step prior to application on the target (extracted method) (1,7,9,13,15,16,18).…”

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confidence: 99%

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Effects of Solid-Medium Type on Routine Identification of Bacterial Isolates by Use of Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry

Anderson

Buchan

Riebe³

et al. 2012

J Clin Microbiol

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Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) is a rapid method for the identification of bacteria. Factors that may alter protein profiles, including growth conditions and presence of exogenous substances, could hinder identification. Bacterial isolates identified by conventional methods were grown on various media and identified using the MALDI Biotyper (Bruker Daltonics, Billerica, MA) using a direct smear method and an acid extraction method. Specimens included 23 Pseudomonas isolates grown on blood agar, Pseudocel (CET), and MacConkey agar (MAC); 20 Staphylococcus isolates grown on blood agar, colistin-nalidixic acid agar (CNA), and mannitol salt agar (MSA); and 25 enteric isolates grown on blood agar, xylose lysine deoxycholate agar (XLD), Hektoen enteric agar (HE), salmonella-shigella agar (SS), and MAC. For Pseudomonas spp., the identification rate to genus using the direct method was 83% from blood, 78% from MAC, and 94% from CET. For Staphylococcus isolates, the identification rate to genus using the direct method was 95% from blood, 75% from CNA, and 95% from MSA. For enteric isolates, the identification rate to genus using the direct method was 100% from blood, 100% from MAC, 100% from XLD, 92% from HE, and 87% from SS. Extraction enhanced identification rates. The direct method of MALDI-TOF analysis of bacteria from selective and differential media yields identifications of varied confidence. Notably, Staphylococci spp. from CNA exhibit low identification rates. Extraction enhances identification rates and is recommended for colonies from this medium. P rompt and accurate identification of bacterial isolates is an objective of the clinical microbiology laboratory and is paramount for patient care. Conventionally this has been achieved using macro-and microscopic observation of morphology and biochemical analysis. These methods often require isolation of individual colonies from polymicrobial cultures and subculture prior to isolate identification. These steps can add significant time to identification of isolates. Molecular methods provide reliable results, though many are expensive to perform, time-consuming, and technically demanding (6). Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has recently emerged as a rapid, accurate, and cost-effective method of identification, applicable to a wide range of bacterial isolates (9,12,13,16,17,19).A major benefit of MALDI-TOF technology is the ability to obtain identifications using a single colony, eliminating the need for subculture and further incubation. To identify most isolates, a single colony can be picked from solid culture media using a swab or toothpick and smeared directly onto a polished steel target plate for identification (direct method) (1, 9, 14, 17, 18). Alternatively, isolates with formidable cell walls or those that produce excess exopolysaccharide matrix (i.e., mucoid pseudomonads) may require processing through a short (approximately 5-min) form...

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Applications of MALDI‐TOF Mass Spectrometry in Clinical Diagnostic Microbiology

Opota

Prod’hom

Greub

2017

MALDI‐TOF and Tandem MS for Clinical Microbiology

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Until recently, microbial identification in clinical diagnostic laboratories has mainly relied on conventional phenotypic and gene sequencing identification techniques. The development of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) devices has revolutionized the routine identification of microorganisms in clinical microbiology laboratories by introducing an easy, rapid, high throughput, low-cost, and efficient identification technique. This technology has been adapted to the constraint of clinical diagnostic laboratories and has the potential to replace and/or complement conventional identification techniques for both bacterial and fungal strains. Using standardized procedures, the resolution of MALDI-TOF MS allows accurate identification at the species level of most Gram-positive and Gram-negative bacterial strains with the exception of a few difficult strains that require more attention and further development of the method. Similarly, the routine identification by MALDI-TOF MS of yeast isolates is reliable and much quicker than conventional techniques. Recent studies have shown that MALDI-TOF MS has also the potential to accurately identify filamentous fungi and dermatophytes, providing that specific standardized procedures are established for these microorganisms. Moreover, MALDI-TOF MS has been used successfully for microbial typing and identification at the subspecies level, demonstrating that this technology is a potential efficient tool for epidemiological studies and for taxonomical classification.

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Identification of Gram-positive anaerobic cocci by MALDI-TOF mass spectrometry

Cited by 76 publications

References 20 publications

Comparison of two matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry methods and API 20AN for identification of clinically relevant anaerobic bacteria

Comparison of two matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry methods and API 20AN for identification of clinically relevant anaerobic bacteria

Effects of Solid-Medium Type on Routine Identification of Bacterial Isolates by Use of Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry

Applications of MALDI‐TOF Mass Spectrometry in Clinical Diagnostic Microbiology

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