scholarly journals Multicenter Evaluation of Rapid BACpro® II for the Accurate Identification of Microorganisms Directly from Blood Cultures Using MALDI-TOF MS

Diagnostics ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2251
Author(s):  
Marina Oviaño ◽  
André Ingebretsen ◽  
Anne K. Steffensen ◽  
Antony Croxatto ◽  
Guy Prod’hom ◽  
...  
Keyword(s):  
Blood Cultures ◽  
Species Level ◽  
Correct Identification ◽  
Gram Positive ◽  
Gram Negative ◽  
Maldi Tof Ms ◽  
Gram Positive Bacteria ◽  
Maldi Tof ◽  
Level Identification ◽  
Tof Ms

The identification of microorganisms directly from blood cultures using MALDI-TOF MS has been shown to be the most impacting application of this methodology. In this study, a novel commercial method was evaluated in four clinical microbiology laboratories. Positive blood culture samples (n = 801) were processed using a rapid BACpro® II kit and then compared with the routine gold standard. A subset of monomicrobial BCs (n = 560) were analyzed in parallel with a Sepsityper® Kit (Bruker Daltonics, Bremen, Germany) and compared with the rapid BACpro® II kit. In addition, this kit was also compared with two different in-house methods. Overall, 80.0% of the monomicrobial isolates (609/761; 95% CI 71.5–88.5) were correctly identified by the rapid BACpro® II kit at the species level (92.3% of the Gram negative and 72.4% of the Gram positive bacteria). The comparison with the Sepsityper® Kit showed that the rapid BACpro® II kit generated higher rates of correct species-level identification for all categories (p > 0.0001), except for yeasts identified with score values > 1.7. It also proved superior to the ammonium chloride method (p > 0.0001), but the differential centrifugation method allowed for higher rates of correct identification for Gram negative bacteria (p > 0.1). The percentage of accurate species-level identification of Gram positive bacteria was particularly noteworthy in comparison with other commercial and in-house methods.

scholarly journals Evaluation of the rapidBACpro® II kit for the rapid identification of microorganisms directly from blood cultures using MALDI-TOF MS

2021 ◽  
Author(s):  
Marina Oviaño ◽  
André Ingebretsen ◽  
Anne K Steffensen ◽  
Antony Croxatto ◽  
Guy Prod’hom ◽  
...  
Keyword(s):  
Blood Cultures ◽  
Species Level ◽  
Correct Identification ◽  
Gram Positive ◽  
Gram Negative ◽  
Maldi Tof Ms ◽  
Gram Positive Bacteria ◽  
Maldi Tof ◽  
Level Identification ◽  
Tof Ms

AbstractObjectivesIdentification of microorganisms directly from blood cultures (BCs) using MALDI-TOF MS has shown to be the application with most impact in this methodology. In this study, a novel commercial method, the rapidBACpro® II, was evaluated in four clinical microbiology laboratories.MethodsPositive blood culture samples (n=801) were processed using the rapidBACpro® II kit and then compared with routine gold standard. A subset of monomicrobial BCs (n=560) were analyzed in parallel with the Sepsityper® kit (Bruker Daltonics, Bremen, Germany) and compared with the rapidBACpro® II kit. In addition, the rapidBACpro® II kit was also compared with two different in-house methods.ResultsOverall, 80.0% of the monomicrobial isolates (609/761) were correctly identified by the rapidBACpro® II kit at the species level (92.3% of the Gram negative and 72.4% of the Gram positive bacteria). The comparison with the Sepsityper® kit yielded higher rates of correct species-level identification provided by the rapidBACpro® II kit for all categories (p>0.0001) except for yeasts identified with score values >1.7. It also proved superior to the ammonium chloride method (p>0.0001) but the differential centrifugation method allowed higher rates of correct identification for Gram negative bacteria (p>0.1).ConclusionsThe rapidBACpro® II kit allowed a high rate of microorganisms correctly identified. The percentage of accurate species-level identification of Gram positive bacteria was particularly noteworthy in comparison with other commercial and in-house methods. This fact was especially interesting in the case of Staphylococcus sp. and Streptococcus sp. in order to elucidate their clinical impact, for example in device-associated bacteremia.

scholarly journals A Prospective Evaluation of Two Rapid Phenotypical Antimicrobial Susceptibility Technologies for the Diagnostic Stewardship of Sepsis

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Cesira Giordano ◽  
Elena Piccoli ◽  
Veronica Brucculeri ◽  
Simona Barnini
Keyword(s):  
Antimicrobial Susceptibility ◽  
Multidrug Resistant ◽  
Rapid Identification ◽  
Blood Cultures ◽  
Gram Positive ◽  
Gram Negative ◽  
Maldi Tof Ms ◽  
Gram Positive Bacteria ◽  
Maldi Tof ◽  
Tof Ms

Rapid identification of bloodstream pathogens by MALDI-TOF MS and the recently introduced rapid antimicrobial susceptibility testing (rAST) directly from positive blood cultures allow clinicians to promptly achieve a targeted therapy, especially for multidrug resistant microorganisms. In the present study, we propose a comparison between phenotypical rASTs performed in light-scattering technology (Alfred 60AST, Alifax®) and fluorescencein situhybridization (Pheno™, Accelerate) directly from positive blood cultures, providing results in 4–7 hours. Blood samples from 67 patients admitted to the Azienda Ospedaliero-Universitaria Pisana were analyzed. After the direct MALDI-TOF MS identification, the rAST was performed at the same time both on Alfred 60AST and Pheno. Alfred 60AST provided qualitative results, interpreted in terms of clinical categories (SIR). Pheno provided identification and MIC values for each antibiotic tested. Results were compared to the broth microdilution assay (SensiTitre™, Thermo Fisher Scientific), according to EUCAST rules. Using Alfred 60AST, an agreement was reached, 91.1% for Gram-negative and 95.7% for Gram-positive bacteria, while using Pheno, the agreement was 90.6% for Gram-negative and 100% for Gram-positive bacteria. Both methods provided reliable results; Alfred 60AST combined with MALDI-TOF MS proved itself faster and cheaper. Pheno provided identification and MIC determination in a single test and, although more expensive, may be useful whenever MIC value is necessary and where MALDI-TOF MS is not present.

Assessment of Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF- MS) for Accurate Bacterial Identification in Clinical Labs

2020 ◽  
Vol 154 (Supplement_1) ◽  
pp. S143-S143
Author(s):  
M Abdel-Rahman ◽  
M S Azab ◽  
M Meibed ◽  
A El-Kholy ◽  
A W Elmetwalli
Keyword(s):  
Blood Cultures ◽  
Bacterial Identification ◽  
Gram Positive ◽  
Gram Negative ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Identification Of Bacteria ◽  
Vitek 2 ◽  
Phenotypic Methods ◽  
Tof Ms

Abstract Introduction/Objective On behalf of the diagnostic Medical Laboratory rapid, and accurate identification of bacteria with their one-to-one anti-microbial susceptibility outlines is of ultimate importance for the management of infected patients. Contemporary microbial identification methods employed in routine clinical diagnostic laboratories relies on the use of conventional phenotypic methods. Phenotypic methods are time consuming with minimum turn-around times of at least 24 hrs and in many occurrences of 48hrs. With the intention of accelerate laboratory processes the MALDI-TOF MS was familiarized. MALDI-TOF MS is established on proteomic profiling and permits for rapid identification of bacteria. This technology has not been widely used in Egypt, but has been regularly used in Europe for the past few years. Methods Two hundred forty three positive non duplicate blood cultures were accrued over a period of six months. Experimental aliquots were taken from excess sample material that was collected as part of routine clinical care. 105 were positive for Gram negative bacilli, 123 were positive for Gram positive cocci, 3 positive for Gram positive bacilli, and 7 were positive for yeast. MALDI-TOF identification was compared to conventional identification. Conventional identification consisted of a combination of MALDI-TOF identification of a subcultures colony by direct smear, biochemical reactions, Vitek 2, and molecular identification. Results Ninety seven of the one hundred and five blood cultures positive for Gram negative bacilli were monomicrobial. The majority of these were identified as Escherichia coli by conventional methods, followed by Klebsiella pneumoniae and Pseudomonas aeruginosa. Eighty-four of these monomicrobial cultures were identified by MALDI-TOF to the species level. Eighty-one of the eighty-four were concordant with the conventional identification (96.4%). Conclusion The MALDI-TOF proved to be useful for the rapid and reliable identification of g-ve bacteria from the clinical specimens. The difference in turnaround time for bacterial identification was significant between MALDI-TOF MS and VITEK 2 with minimal preparation for the blood cultures.

scholarly journals Matrix-assisted Laser Desorption Ionization-Time-of-Flight Mass Spectrometry (MALDI-TOF MS) as a Reliable Tool to Identify Species of Catalase-negative Gram-positive Cocci not Belonging to the Streptococcus Genus

2016 ◽  
Vol 10 (1) ◽  
pp. 202-208 ◽  
Author(s):  
Marisa Almuzara ◽  
Claudia Barberis ◽  
Viviana Rojas Velázquez ◽  
Maria Soledad Ramirez ◽  
Angela Famiglietti ◽  
...  
Keyword(s):  
Extraction Methods ◽  
Species Level ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Genus Level ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Level Identification ◽  
Gram Positive Cocci ◽  
Tof Ms

Objective:To evaluate the performance of matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) by using 190 Catalase-negative Gram-Positive Cocci (GPC) clinical isolates.Methods:All isolates were identified by conventional phenotypic tests following the proposed scheme by Ruoff and Christensen and MALDI-TOF MS (Bruker Daltonics, BD, Bremen, Germany). Two different extraction methods (direct transfer formic acid method on spot and ethanol formic acid extraction method) and different cut-offs for genus/specie level identification were used. The score cut-offs recommended by the manufacturer (≥ 2.000 for species-level, 1.700 to 1.999 for genus level and <1.700 no reliable identification) and lower cut-off scores (≥1.500 for genus level, ≥ 1.700 for species-level and score <1.500 no reliable identification) were considered for identification. A minimum difference of 10% between the top and next closest score was required for a different genus or species.MALDI-TOF MS identification was considered correct when the result obtained from MS database agreed with the phenotypic identification result.When both methods gave discordant results, the 16S rDNA orsodAgenes sequencing was considered as the gold standard identification method. The results obtained by MS concordant with genes sequencing, although discordant with conventional phenotyping, were considered correct. MS results discordant with 16S orsodA identification were considered incorrect.Results:Using the score cut-offs recommended by the manufacturer, 97.37% and 81.05% were correctly identified to genus and species level, respectively. On the other hand, using lower cut-off scores for identification, 97.89% and 94.21% isolates were correctly identified to genus and species level respectively by MALDI-TOF MS and no significant differences between the results obtained with two extraction methods were obtained.Conclusion:The results obtained suggest that MALDI-TOF MS has the potential of being an accurate tool for Catalase-negative GPC identification even for those species with difficult diagnosis asHelcococcus,Abiotrophia,Granulicatella, among others. Nevertheless, expansion of the library, especially including more strains with different spectra on the same species might overcome potential “intraspecies” variability problems. Moreover, a decrease of the identification scores for species and genus-level identification must be considered since it may improve the MALDI-TOF MS accuracy.

scholarly journals A MALDI-TOF MS database with broad genus coverage for species-level identification of Brucella

2018 ◽  
Vol 12 (10) ◽  
pp. e0006874 ◽  
Author(s):  
Jennifer Mesureur ◽  
Sandrine Arend ◽  
Béatrice Cellière ◽  
Priscillia Courault ◽  
Pierre-Jean Cotte-Pattat ◽  
...  
Keyword(s):  
Species Level ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Level Identification ◽  
Tof Ms

Species-Level Discrimination of Psychrotrophic Pathogenic and Spoilage Gram-Negative Raw Milk Isolates Using a Combined MALDI-TOF MS Proteomics–Bioinformatics-based Approach

2017 ◽  
Vol 16 (6) ◽  
pp. 2188-2203 ◽  
Author(s):  
Nuwan R. Vithanage ◽  
Jeevana Bhongir ◽  
Snehal R. Jadhav ◽  
Chaminda S. Ranadheera ◽  
Enzo A. Palombo ◽  
...  
Keyword(s):  
Raw Milk ◽  
Species Level ◽  
Gram Negative ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

scholarly journals Rapid species-level identification of vaginal and oral lactobacilli using MALDI-TOF MS analysis and 16S rDNA sequencing

2014 ◽  
Vol 14 (1) ◽  
Author(s):  
Annette Carola Anderson ◽  
Mohamed Sanunu ◽  
Christian Schneider ◽  
Andreas Clad ◽  
Lamprini Karygianni ◽  
...  
Keyword(s):  
16S Rdna ◽  
Species Level ◽  
16S Rdna Sequencing ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Ms Analysis ◽  
Rdna Sequencing ◽  
Level Identification ◽  
Tof Ms

scholarly journals Development and Validation of an In-House Library for Filamentous Fungi Identification by MALDI-TOF MS in a Clinical Laboratory in Medellin (Colombia)

2020 ◽  
Vol 8 (9) ◽  
pp. 1362
Author(s):  
Juan C. Gómez-Velásquez ◽  
Natalia Loaiza-Díaz ◽  
Gilma Norela Hernández ◽  
Nelson Lima ◽  
Ana C. Mesa-Arango
Keyword(s):  
Filamentous Fungi ◽  
Clinical Laboratory ◽  
Species Level ◽  
Clinical Isolates ◽  
Correct Identification ◽  
Maldi Tof Ms ◽  
Genus Level ◽  
Maldi Tof ◽  
Fungal Identification ◽  
Tof Ms

Identification of filamentous fungi by conventional phenotypic methods are time-consuming, and a correct identification at the species level is prone to errors. Therefore, a more accurate and faster time-to-results, and cost-effective technique, is required, such as the Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS). In this study, we describe the development of an in-house spectra library for the identification of filamentous fungi frequently isolated from patients with infections. An in-house spectra library was constructed using 14 reference strains grown in solid medium. Clinical isolates were identified either by the in-house spectra library or the Biotyper commercial library from Bruker Daltonics. Fungal identification was carried following the Biotyper’s established scores: ≤1.699: not reliably identified (NRI); 1.700–1.999: genus-level; ≥2.000: species-level. Clinical isolates were identified, with the in-house library, at species- and genus-level at 88.70% (55) and 3.22% (2), respectively. While 4.80% (3) was NRI and 3.22% (2) was discrepant concerning sequencing. On the contrary, identification up to species and genus-level with the commercial library was 44.44% (16) and 22.22% (8), respectively. NRI and the discrepancy was 30.55% (11) and 2.77% (1), respectively. For the reaming 26 isolates, 16 from Neoscytalidium dimidiatum and 10 from Sporothrix spp., respectively, the absence of spectrum and the specific spectra within the Sporothrix complex in the commercial library resulted in the inability to obtain an identification. In conclusion, the current results advocate the importance that each clinical microbiological laboratory needs to develop an ad hoc library associated with the MALDI-TOF MS fungal identification to overcome the limitations of the available commercial libraries.

scholarly journals Isolation of Candida auris from cystic fibrosis patient, Greece, April 2019

2019 ◽  
Vol 24 (29) ◽  
Author(s):  
Angeliki Stathi ◽  
Ioanna Loukou ◽  
Helen Kirikou ◽  
Argyri Petrocheilou ◽  
Maria Moustaki ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Fungal Infection ◽  
Cystic Fibrosis Patient ◽  
Species Level ◽  
Sputum Culture ◽  
Candida Auris ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Level Identification ◽  
Tof Ms

We report the first isolation of Candida auris in Greece from a sputum culture of a cystic fibrosis patient in their 20s under posaconazole treatment. The pathogen was identified as C. duobushaemulonii by VITEK2YST, but as C. auris by MALDI-TOF MS. This case underscores the need for species-level identification of all non-albicans Candida (NAC) isolates from cystic fibrosis patients and patients with predisposing factors to fungal infection.

scholarly journals Performance of MALDI-TOF Mass Spectrometry for the Identification of the HACEK Group and Other Fastidious Gram-Negative Rods

2019 ◽  
Vol 13 (1) ◽  
pp. 216-221 ◽  
Author(s):  
Marisa Almuzara ◽  
Karen C. V. Cárdenas ◽  
Claudia Barberis ◽  
Maria S. Ramirez ◽  
Angela Famiglietti ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Formic Acid ◽  
Extraction Methods ◽  
Species Level ◽  
Acid Extraction ◽  
Gram Negative ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Routine Identification ◽  
Tof Ms

Objective: The aim of this study was to determine the capacity of matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) to identify 155 HACEK clinical isolates and other fastidious or infrequently isolated Gram-negative rods (e.g., Actinobacillus, Capnocytophaga, Pasteurella, Neisseria, Moraxella, Dysgonomonas, among others). Methods: All the isolates were identified by standard biochemical tests and MALDI-TOF MS. Two different extraction methods (direct transfer formic acid method on spot and ethanol formic acid extraction method) and different cut-offs for genus/specie level identification were used. MALDI-TOF MS identification was considered correct when the result obtained from the MS database agreed with the phenotypic identification result. When both the methods gave discordant results, the 16S rDNA gene sequencing was considered as the gold standard identification method. Results: Employing the score cut-offs suggested by the manufacturer, 93.55% and 69.03% isolates were correctly identified at the genus and species level, respectively. On the contrary , employing lower cut-off scores for identification, 98.06% and 92.09% isolates were properly identified at the genus and species level respectively and no significant differences between the results obtained with two extraction methods were observed . Conclusion: The accurate identification of 14 genera showed the reliability of MALDI-TOF MS as an optional methodology to the routine identification methods currently used in laboratories.

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