Identification of Staphylococcus pseudintermedius isolates from wound cultures by MALDI-TOF MS improves accuracy of susceptibility reporting at an increase in cost

2021 ◽  
Author(s):  
Helen L. Bibby ◽  
Kristen L. Brown
Keyword(s):  
Susceptibility Testing ◽  
Biochemical Tests ◽  
Additional Time ◽  
Identification Procedure ◽  
Staphylococcus Pseudintermedius ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Before And After ◽  
Coagulase Positive Staphylococci ◽  
Tof Ms

Staphylococcus pseudintermedius can easily be mistaken for Staphylococcus aureus using phenotypic and rapid biochemical methods. We began confirming the identification of all coagulase-positive staphylococci isolated from human wound cultures at our centralized laboratory, servicing both community and inpatients, with MALDI-TOF MS instead of using phenotypic and rapid biochemical tests, and determined the prevalence of S. pseudintermedius since the change in identification procedure and at what cost. A retrospective review was performed on all wound swab cultures from which coagulase-positive staphylococci were isolated 7 months before and after the change in identification procedure. A total of 49 S. intermedius /pseudintermedius (SIP) isolates were identified including 7 isolates from 14,401 wound cultures in the before period and 42 isolates from 14,147 wound cultures in the after period. The number of SIP isolates as a proportion of isolated coagulase-positive staphylococci increased significantly from the before 7/6,351 (0.1%) to the after period 42/5,435 (0.7%) (difference 0.6% (95% CI 0.037-0.83%, p <0.0001)). Antibiotic susceptibility testing was performed in 42 isolates; none had an oxacillin MIC 1.0-2.0 μg/mL, the range in which if the isolate was misidentified as S. aureus , a very major error in susceptibility interpretation would occur. The increase in cost of the change in identification procedure was $17,558 CDN per year in our laboratory performing microbiology testing for community and acute care patients in a zone servicing nearly 1.7 million people. While we will only continue to learn more about this emerging pathogen if we make attempts to properly identify it in clinical cultures, the additional time and cost involved may be unacceptably high in some laboratories.

scholarly journals MALDI-TOF MS-based drug susceptibility testing of pathogens: The example ofCandida albicansand fluconazole

PROTEOMICS ◽  
2009 ◽  
Vol 9 (20) ◽  
pp. 4627-4631 ◽  
Author(s):  
Carine Marinach ◽  
Alexandre Alanio ◽  
Martine Palous ◽  
St��phanie Kwasek ◽  
Arnaud Fekkar ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

scholarly journals Prospective Evaluation of Light Scatter Technology Paired with Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry for Rapid Diagnosis of Urinary Tract Infections

2017 ◽  
Vol 55 (6) ◽  
pp. 1802-1811 ◽  
Author(s):  
Sandra Montgomery ◽  
Kiana Roman ◽  
Lan Ngyuen ◽  
Ana Maria Cardenas ◽  
James Knox ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Automated System ◽  
Light Scatter ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tract Infections ◽  
Organism Identification ◽  
Tof Ms

ABSTRACTUrinary tract infections are one of the most common reasons for health care visits. Diagnosis and optimal treatment often require a urine culture, which takes an average of 1.5 to 2 days from urine collection to results, delaying optimal therapy. Faster, but accurate, alternatives are needed. Light scatter technology has been proposed for several years as a rapid screening tool, whereby negative specimens are excluded from culture. A commercially available light scatter device, BacterioScan 216Dx (BacterioScan, Inc.), has recently been advertised for this application. Paired use of mass spectrometry (MS) for bacterial identification and automated-system-based susceptibility testing straight from the light scatter suspension might provide dramatic improvement in times to a result. The present study prospectively evaluated the BacterioScan device, with culture as the reference standard. Positive light scatter specimens were used for downstream rapid matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) MS organism identification and automated-system-based antimicrobial susceptibility testing. Prospective evaluation of 439 urine samples showed a sensitivity of 96.5%, a specificity of 71.4%, and positive and negative predictive values of 45.1% and 98.8%, respectively. MALDI-TOF MS analysis of the suspension after density-based selection yielded a sensitivity of 72.1% and a specificity of 96.9%. Antimicrobial susceptibility testing of the samples identified by MALDI-TOF MS produced an overall categorical agreement of 99.2%. Given the high sensitivity and negative predictive value of results obtained, BacterioScan 216Dx is a reasonable approach for urine screening and might produce negative results in as few as 3 h, with no downstream workup. Paired rapid identification and susceptibility testing might be useful when MALDI-TOF MS results in an organism identification, and it might decrease the time to a result by more than 24 h.

scholarly journals Evaluation of ID Fungi Plates Medium for Identification of Molds by MALDI Biotyper

2020 ◽  
Vol 58 (5) ◽  
Author(s):  
Marie Gladys Robert ◽  
Charlotte Romero ◽  
Céline Dard ◽  
Cécile Garnaud ◽  
Odile Cognet ◽  
...  
Keyword(s):  
Filamentous Fungi ◽  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
Antifungal Susceptibility Testing ◽  
Maldi Tof Ms ◽  
Extraction Protocol ◽  
Maldi Tof ◽  
Morphological Aspects ◽  
Routine Identification ◽  
Tof Ms

ABSTRACT MALDI-TOF mass spectrometry (MS) identification of pathogenic filamentous fungi is often impaired by difficulties in harvesting hyphae embedded in the medium and long extraction protocols. The ID Fungi Plate (IDFP) is a novel culture method developed to address such difficulties and improve the identification of filamentous fungi by MALDI-TOF MS. We cultured 64 strains and 11 clinical samples on IDFP, Sabouraud agar-chloramphenicol (SAB), and ChromID Candida agar (CAN2). We then compared the three media for growth, ease of harvest, amount of material picked, and MALDI-TOF identification scores after either rapid direct transfer (DT) or a long ethanol-acetonitrile (EA) extraction protocol. Antifungal susceptibility testing and microscopic morphology after subculture on SAB and IDFP were also compared for ten molds. Growth rates and morphological aspects were similar for the three media. With IDFP, harvesting of fungal material for the extraction procedure was rapid and easy in 92.4% of cases, whereas it was tedious on SAB or CAN2 in 65.2% and 80.3% of cases, respectively. The proportion of scores above 1.7 (defined as acceptable identification) were comparable for both extraction protocols using IDFP (P = 0.256). Moreover, rates of acceptable identification after DT performed on IDFP (93.9%) were significantly higher than those obtained after EA extraction with SAB (69.7%) or CAN2 (71.2%) (P = <0.001 and P = 0.001, respectively). Morphological aspects and antifungal susceptibility testing were similar between IDFP and SAB. IDFP is a culture plate that facilitates and improves the identification of filamentous fungi, allowing accurate routine identification of molds with MALDI-TOF-MS using a rapid-extraction protocol.

scholarly journals Application of MALDI-TOF mass spectrometry in clinical diagnostic microbiology

2014 ◽  
Vol 8 (09) ◽  
pp. 1081-1088 ◽  
Author(s):  
Elena De Carolis ◽  
Antonietta Vella ◽  
Luisa Vaccaro ◽  
Riccardo Torelli ◽  
Teresa Spanu ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Drug Susceptibility ◽  
Biochemical Tests ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Bacteria And Fungi ◽  
Diagnostic Microbiology ◽  
Tof Ms

Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) has recently emerged as a powerful technique for identification of microorganisms, changing the workflow of well-established laboratories so that its impact on microbiological diagnostics has been unparalleled. In comparison with conventional identification methods that rely on biochemical tests and require long incubation procedures, MALDI-TOF MS has the advantage of identifying bacteria and fungi directly from colonies grown on culture plates in a few minutes and with simple procedures. Numerous studies on different systems available demonstrate the reliability and accuracy of the method, and new frontiers have been explored besides microbial species level identification, such as direct identification of pathogens from positive blood cultures, subtyping, and drug susceptibility detection.

scholarly journals MALDI-TOF MS Detection of Endophytic Bacteria Associated with Great Nettle (Urtica dioica L.), Grown in Algeria

2018 ◽  
Vol 67 (1) ◽  
pp. 67-72 ◽  
Author(s):  
Souheyla Toubal ◽  
Ouahiba Bouchenak ◽  
Djillali Elhaddad ◽  
Karima Yahiaoui ◽  
Sarah Boumaza ◽  
...  
Keyword(s):  
Endophytic Bacteria ◽  
Vascular System ◽  
Common Species ◽  
Urtica Dioica ◽  
Biochemical Tests ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Identification Of Bacteria ◽  
The Common ◽  
Tof Ms

Any plant with a vascular system has a specific endophytic microflora. The identification of bacteria is essential in plant pathology. Although identification methods are effective, they are costly and time consuming. The purpose of this work is to isolate and to identify the different bacteria from the internal tissues of Urtica dioica L. and to study their diversity. This last is based on the different parts of the plant (stems, leaves and roots) and the harvest regions (Dellys and Tlamcen). The identification of bacteria is done by biochemical tests and confirmed by MALDI-TOF MS. Seven genus and eleven species were isolated from the Great Nettle. They belong to the genera Bacillus, Escherichia, Pantoea, Enterobacter, Staphylococcus, Enterococcus and Paenibacillus. The majority of these bacteria were isolated from Tlemcen which makes this region the richest in endophytic bacteria compared to that harvested from Dellys. The results show also that the leaves are the most diversified in endophytic bacteria. Bacillus pumilus-ME is the common species of the three parts of the plant harvested in both regions. From this work, it emerges that the Great Nettle can be settled by various endophytic bacteria which are differently distributed within the same plant harvested in different regions.

scholarly journals Rapid antibiotic susceptibility testing on blood cultures using MALDI-TOF MS

PLoS ONE ◽  
2018 ◽  
Vol 13 (10) ◽  
pp. e0205603 ◽  
Author(s):  
Marlène Sauget ◽  
Xavier Bertrand ◽  
Didier Hocquet
Keyword(s):  
Antibiotic Susceptibility ◽  
Susceptibility Testing ◽  
Blood Cultures ◽  
Antibiotic Susceptibility Testing ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

scholarly journals Short Incubation of Positive Blood Cultures on Solid Media for Species Identification by MALDI-TOF MS: Which Agar Is the Fastest?

2021 ◽  
Author(s):  
Neele J. Froböse ◽  
Evgeny A. Idelevich ◽  
Frieder Schaumburg
Keyword(s):  
Mass Spectrometry ◽  
Species Identification ◽  
Susceptibility Testing ◽  
Solid Medium ◽  
Blood Cultures ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Solid Media ◽  
Laboratory Results ◽  
Tof Ms

When blood cultures are flagged as positive, they are incubated on solid media to produce enough biomass of the bacterium for identification and susceptibility testing. Rapid turnaround times for laboratory results could save lives, and we wanted to assess which solid medium is best to shorten the time to species identification using MALDI-TOF mass spectrometry.

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