scholarly journals Candida auris Identification and Rapid Antifungal Susceptibility Testing Against Echinocandins by MALDI-TOF MS

2019 ◽  
Vol 9 ◽  
Author(s):  
Mansoureh Vatanshenassan ◽  
Teun Boekhout ◽  
Jacques F. Meis ◽  
Judith Berman ◽  
Anuradha Chowdhary ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
Antifungal Susceptibility Testing ◽  
Candida Auris ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

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 Drug Resistance-Associated Mutations in ERG11 of Multidrug-Resistant Candida auris in a Tertiary Care Hospital of Eastern Saudi Arabia

2020 ◽  
Vol 7 (1) ◽  
pp. 18
Author(s):  
Reem AlJindan ◽  
Doaa M. AlEraky ◽  
Nehal Mahmoud ◽  
Baha Abdalhamid ◽  
Mashael Almustafa ◽  
...  
Keyword(s):  
Drug Resistance ◽  
18S Rrna ◽  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
18S Rrna Gene ◽  
Rrna Gene ◽  
Candida Auris ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

Candida auris is an emerging multi-drug resistant pathogen with high mortality rate; nosocomial infections have been reported worldwide, causing a major challenge for clinicians and microbiological laboratories. The study aims to describe new cases of C. auris and detect drug resistance-associated mutations of C. auris by the sequencing of ERG11 and FKS1 genes. A total of six specimens were collected from blood, urine, ear swab, and groin screening samples. Isolates were incubated for 48 h on Sabouraud Dextrose agar (SDA) at 42 °C, then confirmed by MALDI-TOF MS. Furthermore, antifungal susceptibility testing was performed using the Vitek 2 system to detect Minimum Inhibitory Concentrations (MICs) of six antifungals. Sequences of 18S rRNA gene and ITS regions from isolates and phylogenetic analysis were performed. Gene sequencing was analysed to detect drug resistance-associated mutations by FKS1 and ERG11 genes sequencing. All C. auris isolates were confirmed by MALDI-TOF MS, and evolutionary analyses using sequences of 18S rRNA gene and ITS region. Antifungal susceptibility testing showed that all isolates were resistant to fluconazole. Sequencing of ERG11 and FKS1 genes from the isolates revealed the presence of two (F132Y and K143R) drug resistance-associated mutations in ERG11, however, FKS1 gene was devoid of mutations. The study sheds light on a public health threat of an emerging pathogen, and the hospital implemented strict contact screening and infection control precautions to prevent C. auris infection. Finally, there is a critical need to monitor the antifungal resistance in different geographical areas and implementation of efficient guidelines for treatment.

scholarly journals Candida auris Clinical Isolates from South Korea: Identification, Antifungal Susceptibility, and Genotyping

2019 ◽  
Vol 57 (4) ◽  
Author(s):  
Yong Jun Kwon ◽  
Jong Hee Shin ◽  
Seung A Byun ◽  
Min Ji Choi ◽  
Eun Jeong Won ◽  
...  
Keyword(s):  
Antifungal Susceptibility ◽  
Diagnostic Tools ◽  
Candida Auris ◽  
Content Type ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Fluconazole Resistant ◽  
Vitek 2 ◽  
Vitek Ms ◽  
Tof Ms

ABSTRACT Candida auris is an emerging worldwide fungal pathogen. Over the past 20 years, 61 patient isolates of C. auris (4 blood and 57 ear) have been obtained from 13 hospitals in Korea. Here, we reanalyzed those molecularly identified isolates using two matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) systems, including Biotyper and Vitek MS, followed by antifungal susceptibility testing, sequencing of the ERG11 gene, and genotyping. With a research-use-only (RUO) library, 83.6% and 93.4% of the isolates were correctly identified by Biotyper and Vitek MS, respectively. Using an in vitro diagnostic (IVD) library of Vitek MS, 96.7% of the isolates were correctly identified. Fluconazole-resistant isolates made up 62.3% of the isolates, while echinocandin- or multidrug-resistant isolates were not found. Excellent essential (within two dilutions, 96.7%) and categorical agreements (93.4%) between the Clinical and Laboratory Standards Institute (CLSI) and Vitek 2 (AST-YS07 card) methods were observed for fluconazole. Sequencing ERG11 for all 61 isolates revealed that only 3 fluconazole-resistant isolates showed the Erg11p amino acid substitution K143R. All 61 isolates showed identical multilocus sequence typing (MLST). Pulsed-field gel electrophoresis (PFGE) analyses revealed that both blood and ear isolates had the same or similar patterns. These results show that MALDI-TOF MS and Vitek 2 antifungal susceptibility systems can be reliable diagnostic tools for testing C. auris isolates from Korean hospitals. The Erg11p mutation was seldom found among Korean isolates of C. auris, and multidrug resistance was not found. Both MLST and PFGE analyses suggest that these isolates are genetically similar.

scholarly journals Antifungal Susceptibility Testing of Aspergillus spp. by Using a Composite Correlation Index (CCI)-Based Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry Method Appears To Not Offer Benefit over Traditional Broth Microdilution Testing

2017 ◽  
Vol 55 (7) ◽  
pp. 2030-2034 ◽  
Author(s):  
Melissa R. Gitman ◽  
Lisa McTaggart ◽  
Joanna Spinato ◽  
Rahgavi Poopalarajah ◽  
Erin Lister ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
Laser Desorption Ionization ◽  
Wild Type ◽  
Ionization Time ◽  
Content Type ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Tof Ms

ABSTRACT Aspergillus spp. cause serious invasive lung infections, and Aspergillus fumigatus is the most commonly encountered clinically significant species. Voriconazole is considered to be the drug of choice for treating A. fumigatus infections; however, rising resistance rates have been reported. We evaluated a matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS)-based method for the differentiation between wild-type and non-wild-type isolates of 20 Aspergillus spp. (including 2 isolates of Aspergillus ustus and 1 of Aspergillus calidoustus that were used as controls due their intrinsic low azole susceptibility with respect to the in vitro response to voriconazole). At 30 and 48 h of incubation, there was complete agreement between Cyp51A sequence analysis, broth microdilution, and MALDI-TOF MS classification of isolates as wild type or non-wild type. In this proof-of-concept study, we demonstrated that MALDI-TOF MS can be used to accurately detect A. fumigatus strains with reduced voriconazole susceptibility. However, rather than proving to be a rapid and simple method for antifungal susceptibility testing, this particular MS-based method showed no benefit over conventional testing methods.

scholarly journals Rapid Antifungal Susceptibility Testing of Yeasts and Molds by MALDI-TOF MS: A Systematic Review and Meta-Analysis

2021 ◽  
Vol 7 (1) ◽  
pp. 63
Author(s):  
Miriam Alisa Knoll ◽  
Hanno Ulmer ◽  
Cornelia Lass-Flörl
Keyword(s):  
Susceptibility Testing ◽  
Meta Analysis ◽  
Antifungal Susceptibility ◽  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

Due to the growing burden of fungal infections and a recent rise in antifungal resistance, antifungal susceptibility testing (AFST) is of increasing importance. The common methods of AFST have turnaround times of 24 to 48 h, and the available rapid methods are limited by applicability, cost-efficiency or accuracy. Given the urgency of adequate antifungal treatment in invasive mycoses, the need for the rapid and reliable detection of resistance is evident. In this systematic review and meta-analysis, we evaluated the diagnostic accuracy of AFST based on matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS). Twelve studies were reviewed, and data for the comparative analysis of their accuracy and methodology were systematically extracted. Compared to broth dilution as the gold standard, MALDI-TOF MS-based AFST reached a pooled sensitivity and specificity of 91% (95% Confidence Interval [CI], 84% to 96%) and 95% (95% CI, 90% to 98%), respectively. A comparative analysis showed that the sensitivity was higher for the semi-quantitative matrix-assisted laser desorption ionization Biotyper antibiotic susceptibility test rapid assay (MBT ASTRA) technique (96%) than for the correlate composite index (CCI) approach (85%), which is based on spectrum changes. Turnaround times below eight hours reached better diagnostic values than longer incubation periods, qualifying MALDI-TOF MS-based AFST as a rapid and accurate method for the detection of antifungal resistance.

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.

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.

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