scholarly journals Identification and Antifungal Susceptibility Profiles of Candida haemulonii Species Complex Clinical Isolates from a Multicenter Study in China

2016 ◽  
Vol 54 (11) ◽  
pp. 2676-2680 ◽  
Author(s):  
Xin Hou ◽  
Meng Xiao ◽  
Sharon C.-A. Chen ◽  
He Wang ◽  
Jing-Wei Cheng ◽  
...  
Keyword(s):  
Species Identification ◽  
Antifungal Susceptibility ◽  
Reference Method ◽  
Its Sequencing ◽  
Species Classification ◽  
Content Type ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Candida Haemulonii ◽  
Tof Ms

Candida haemulonii complex ( Candida haemulonii , Candida haemulonii var. vulnera , and Candida duobushaemulonii ) consists of emerging pathogens. Thirty-one isolates from 14 hospitals in China were studied for their species classification and antifungal susceptibilities. Performances of molecular (i.e., ribosomal DNA [rDNA] internal transcribed spacer [ITS] sequencing, D1/D2 sequencing, and ITS sequencer-based capillary gel electrophoresis [SCGE]) and phenotypic identification methods in species identification were compared. Twenty-six (83.9%) of 31 isolates were identified as C. haemulonii and 5 isolates were identified as C. duobushaemulonii by ITS sequencing as the reference method; results obtained by D1/D2 sequencing and ITS SCGE were concordant with those obtained by ITS sequencing for all (100%) of the isolates. All 31 isolates were identified as C. haemulonii by the Vitek matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) system (bioMérieux, France), whereas the Bruker MS system (Bruker Daltoniks, Germany) correctly provided species identification for 77.4% and 100% of isolates using cutoff scores for species of ≥2.0 and ≥1.70, respectively. The Vitek 2 compact (bioMérieux) only identified 9 (29%) of 31 isolates. All isolates showed high MICs for amphotericin B (range, 2 to >8 μg/ml) and fluconazole (≥128 μg/ml) but low MICs (≤0.5 μg/ml) for the echinocandins. Our results reinforce the need for MALDI-TOF MS and/or molecular differentiation of species within the C. haemulonii complex. The multiresistant antifungal susceptibility profile of these isolates represents a challenge to therapy.

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 Identification of Nocardia species using Autof MS 1000 and Bruker MALDI-TOF MS systems: A comparison

2021 ◽  
Author(s):  
Bing Ma ◽  
Yunqi Tian ◽  
Yungang Han ◽  
Lifang Ban ◽  
Junwen Yang ◽  
...  
Keyword(s):  
Species Identification ◽  
Protein Extraction ◽  
Reference Method ◽  
Invasive Disease ◽  
Species Level ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Significant Difference ◽  
Tof Ms

ABSTRACTNocardia is an important cause of clinically invasive disease, but for most clinical laboratories, identification of these isolates to the species level is challenging. Recently, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been widely used for identification of most bacterial and fungal isolates. In this multicenter study, we evaluated the identification of Nocardia isolates using Autof MS1000 and Bruker Biotyper. A total of 86 non-duplicate Nocardia isolates from 7 hospital laboratories were evaluated. Further, we carried out sequence analysis of 16S rRNA, gyrB, secA1, hsp65, and rpoB genes as a reference method for Nocardia species identification. The 86 isolates were directly spotted on the target plate and plate protein extraction was performed. Data were analyzed by SPSS 19.0. In total, 72 (83.7%) strains (score ≥ 9.0) and 70 (81.4%) strains (score ≥ 2.0) were correctly identified by the Autof MS1000 and Bruker Biotyper systems, respectively, at the species level. There was no significant difference (P > 0.05) between the two systems using the same protein extraction method. In conclusion, the Autof MS 1000 and Bruker MALDI-TOF systems showed no difference in identification of Nocardia spp. to the species level and could meet the most important clinical requirement for species identification.

Multicenter evaluation of three different MALDI-TOF MS systems for identification of clinically relevant filamentous fungi

2020 ◽  
Vol 59 (1) ◽  
pp. 81-86
Author(s):  
Yue Sun ◽  
Jian Guo ◽  
Rong Chen ◽  
Liang Hu ◽  
Qihang Xia ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Filamentous Fungi ◽  
Reference Method ◽  
Species Level ◽  
Its Sequencing ◽  
Maldi Tof Ms ◽  
Genus Level ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Tof Ms

Abstract Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) holds promise as a potential tool for clinical identification of filamentous fungi. However, due to the lack of an appropriate extraction protocol and the difficulty of database building, the identification power of each system differs. In this study, we selected 126 clinical mould isolates comprising 28 species identified using internal transcribed spacer (ITS) sequencing as the reference method to evaluate three MALDI-TOF MS systems. When using cultures and sample preparation as recommended by the respective vendors, of the 126 strains tested, VITEK MS identified 121 (96.0%) to species-level and 124 (98.4%) to genus-level; Biotyper identified 53 (42.1%) to species-level and 54 (42.9%) to genus-level; Autof identified 74 (58.7%) to species-level and 76 (60.3%) to genus-level. For the Autof system, the tube extraction method recommended by the vendor performed better (59%) than the on-plate lysis (51%). Our study demonstrates that MALDI-TOF MS systems can successfully identify most clinically relevant fungi, while performance is still highly dependent on the database and sample preparation protocol.

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 Evaluating and Improving Vitek MS for Identification of Clinically Relevant Species of Trichosporon and the Closely Related Genera Cutaneotrichosporon and Apiotrichum

2017 ◽  
Vol 55 (8) ◽  
pp. 2439-2444 ◽  
Author(s):  
João N. de Almeida ◽  
Viviane M. Favero Gimenes ◽  
Elaine C. Francisco ◽  
Lumena P. Machado Siqueira ◽  
Renato K. Gonçalves de Almeida ◽  
...  
Keyword(s):  
Species Identification ◽  
Large Set ◽  
Spectral Profile ◽  
Content Type ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Microorganism Identification ◽  
Vitek Ms ◽  
Tof Ms

ABSTRACT Trichosporon species are relevant etiologic agents of hospital-acquired infections. High mortality rates are attributed to Trichosporon deep-seated infections in immunocompromised individuals, making fast and accurate species identification relevant for hastening the discovery of best-targeted therapy. Recently, Trichosporon taxonomy has been reassessed, and three genera have been proposed for the pathogenic species: Trichosporon , Cutaneotrichosporon , and Apiotrichum . Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) has replaced old phenotypic methods for microorganism identification in clinical laboratories, but spectral profile databases have to be evaluated and improved for optimal species identification performance. Vitek MS (bioMérieux) is one of the commercially available MALDI-TOF MS platforms for pathogen identification, and its spectral profile databases remain poorly evaluated for Trichosporon , Cutaneotrichosporon , and Apiotrichum species identification. We herein evaluated and improved Vitek MS for the identification of the main clinical relevant species of Trichosporon , Cutaneotrichosporon , and Apiotrichum using a large set of strains and isolates belonging to different yeast collections in Brazil and France.

scholarly journals Resistance and Heteroresistance to Colistin in Pseudomonas aeruginosa Isolates from Wenzhou, China

2019 ◽  
Vol 63 (10) ◽  
Author(s):  
Jie Lin ◽  
Chunquan Xu ◽  
Renchi Fang ◽  
Jianming Cao ◽  
Xiucai Zhang ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Lipid A ◽  
Population Analysis ◽  
Colistin Resistance ◽  
Content Type ◽  
Maldi Tof Ms ◽  
Expression Levels ◽  
Maldi Tof ◽  
Broth Microdilution Method ◽  
Tof Ms

ABSTRACT The goal was to investigate the mechanisms of colistin resistance and heteroresistance in Pseudomonas aeruginosa clinical isolates. Colistin resistance was determined by the broth microdilution method. Colistin heteroresistance was evaluated by population analysis profiling. Time-kill assays were also conducted. PCR sequencing was performed to detect the resistance genes among (hetero)resistant isolates, and quantitative real-time PCR assays were performed to determine their expression levels. Pulsed-field gel electrophoresis and multilocus sequence typing were performed. Lipid A characteristics were determined via matrix-assisted laser desorption–ionization time of flight mass spectrometry (MALDI-TOF MS). Two resistant isolates and 9 heteroresistant isolates were selected in this study. Substitutions in PmrB were detected in 2 resistant isolates. Among heteroresistant isolates, 8 of 9 heteroresistant isolates had nonsynonymous PmrB substitutions, and 2 isolates, including 1 with a PmrB substitution, had PhoQ alterations. Correspondingly, the expression levels of pmrA or phoP were upregulated in PmrB- or PhoQ-substituted isolates. One isolate also found alterations in ParRS and CprRS. The transcript levels of the pmrH gene were observed to increase across all investigated isolates. MALDI-TOF MS showed additional 4-amino-4-deoxy-l-arabinose (l-Ara4N) moieties in lipid A profiles in (hetero)resistant isolates. In conclusion, both colistin resistance and heteroresistance in P. aeruginosa in this study mainly involved alterations of the PmrAB regulatory system. There were strong associations between mutations in specific genetic loci for lipid A synthesis and regulation of modifications to lipid A. The transition of colistin heteroresistance to resistance should be addressed in future clinical surveillance.

scholarly journals Performance of Five Commercial Identification Platforms for Identification of Staphylococcus delphini

2019 ◽  
Vol 57 (11) ◽  
Author(s):  
Matthew C. Canver ◽  
Tsigereda Tekle ◽  
Samantha T. Compton ◽  
Katrina Callan ◽  
Eileen M. Burd ◽  
...  
Keyword(s):  
Distinct Species ◽  
Human Infection ◽  
Species Level ◽  
Accurate Identification ◽  
Content Type ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Staphylococcus Intermedius ◽  
Animal Pathogens ◽  
Tof Ms

ABSTRACT The Staphylococcus intermedius group (SIG) is a collection of coagulase-positive staphylococci consisting of four distinct species, namely, Staphylococcus cornubiensis, Staphylococcus delphini, Staphylococcus intermedius, and Staphylococcus pseudintermedius. SIG members are animal pathogens and rare causes of human infection. Accurate identification of S. pseudintermedius has important implications for interpretation of antimicrobial susceptibility testing data and may be important for other members of the group. Therefore, we sought to evaluate the performance of five commercially available identification platforms with 21 S. delphini isolates obtained from a variety of animal and geographic sources. Here, we show that automated biochemical platforms were unable to identify S. delphini to the species level, a function of its omission from their databases, but could identify isolates to the SIG level with various degrees of success. However, all automated systems misidentified at least one isolate as Staphylococcus aureus. One matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) system was able to identify S. delphini to the species level, suggesting that MALDI-TOF MS is the best option for distinguishing members of the SIG. With the exception of S. pseudintermedius, it is unclear if other SIG members should be routinely identified to the species level; however, as our understanding of their role in animal and human diseases increases, it may be necessary and important to do so.

Species identification of Streptococcus bovis group isolates causing bacteremia: a comparison of two MALDI-TOF MS systems

2017 ◽  
Vol 88 (1) ◽  
pp. 23-25 ◽  
Author(s):  
Charlotte N. Agergaard ◽  
Elisa Knudsen ◽  
Rimtas Dargis ◽  
Xiaohui C. Nielsen ◽  
Jens J. Christensen ◽  
...  
Keyword(s):  
Species Identification ◽  
Streptococcus Bovis ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

Dermatophytic mycetoma of the scalp due to an atypical strain of Microsporum audouinii identified by MALDI-TOF MS and ITS sequencing

2019 ◽  
Vol 29 (2) ◽  
pp. 185-188 ◽  
Author(s):  
K. Diongue ◽  
A. Boye ◽  
L. Bréchard ◽  
M.A. Diallo ◽  
H. Dione ◽  
...  
Keyword(s):  
Its Sequencing ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Microsporum Audouinii ◽  
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.

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