Actinotignum (formerly Actinobaculum) schaalii: a review of MALDI-TOF for identification of clinical isolates, and a proposed method for presumptive phenotypic identification

Pathology ◽  
2016 ◽  
Vol 48 (4) ◽  
pp. 367-371 ◽  
Author(s):  
Robert P. Stevens ◽  
Peter C. Taylor
Keyword(s):  
Clinical Isolates ◽  
Phenotypic Identification ◽  
Maldi Tof ◽  
Actinobaculum Schaalii

Black aspergilli: A remaining challenge in fungal taxonomy?

2018 ◽  
Vol 57 (6) ◽  
pp. 773-780 ◽  
Author(s):  
Elizabet D’hooge ◽  
Pierre Becker ◽  
Dirk Stubbe ◽  
Anne-Cécile Normand ◽  
Renaud Piarroux ◽  
...  
Keyword(s):  
Antifungal Susceptibility ◽  
Identification Accuracy ◽  
Clinical Isolates ◽  
Reference Database ◽  
Data Set ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Tof Ms

AbstractAspergillus section Nigri is a taxonomically difficult but medically and economically important group. In this study, an update of the taxonomy of A. section Nigri strains within the BCCM/IHEM collection has been conducted. The identification accuracy of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was tested and the antifungal susceptibilities of clinical isolates were evaluated. A total of 175 strains were molecularly analyzed. Three regions were amplified (ITS, benA, and caM) and a multi-locus phylogeny of the combined loci was created by using maximum likelihood analysis. The in-house MALDI-TOF MS reference database was extended and an identification data set of 135 strains was run against a reference data set. Antifungal susceptibility was tested for voriconazole, itraconazole, and amphotericin B, using the EUCAST method. Phylogenetic analysis revealed 18 species in our data set. MALDI-TOF MS was able to distinguish between A. brasiliensis, A. brunneoviolaceus, A. neoniger, A. niger, A. tubingensis, and A. welwitschiae of A. sect. Nigri. In the routine clinical lab, isolates of A. sect. Nigri are often identified as A. niger. However, in the clinical isolates of our data set, A. tubingensis (n = 35) and A. welwitschiae (n = 34) are more common than A. niger (n = 9). Decreased antifungal susceptibility to azoles was observed in clinical isolates of the /tubingensis clade. This emphasizes the importance of identification up to species level or at least up to clade level in the clinical lab. Our results indicate that MALDI-TOF MS can be a powerful tool to replace classical morphology.

scholarly journals Performances and Reliability of Bruker Microflex LT and VITEK MS MALDI-TOF Mass Spectrometry Systems for the Identification of Clinical Microorganisms

2015 ◽  
Vol 2015 ◽  
pp. 1-18 ◽  
Author(s):  
Kivanc Bilecen ◽  
Gorkem Yaman ◽  
Ugur Ciftci ◽  
Yahya Rauf Laleli
Keyword(s):  
Mass Spectrometry ◽  
Clinical Microbiology ◽  
Identification Accuracy ◽  
Clinical Microbiology Laboratory ◽  
Maldi Tof Ms ◽  
Microbial Identification ◽  
Phenotypic Identification ◽  
Maldi Tof ◽  
Vitek Ms ◽  
Tof Ms

In clinical microbiology laboratories, routine microbial identification is mostly performed using culture based methodologies requiring 24 to 72 hours from culturing to identification. Matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) technology has been established as a cost effective, reliable, and faster alternative identification platform. In this study, we evaluated the reliability of the two available MALDI-TOF MS systems for their routine clinical level identification accuracy and efficiency in a clinical microbiology laboratory setting. A total of 1,341 routine phenotypically identified clinical bacterial and fungal isolates were selected and simultaneously analyzed using VITEK MS (bioMérieux, France) and Microflex LT (Bruker Diagnostics, Germany) MALDI-TOF MS systems. For any isolate that could not be identified with either of the systems and for any discordant result, 16S rDNA gene or ITS1/ITS2 sequencing was used. VITEK MS and Microflex LT correctly identified 1,303 (97.17%) and 1,298 (96.79%) isolates to the species level, respectively. In 114 (8.50%) isolates initial phenotypic identification was inaccurate. Both systems showed a similar identification efficiency and workflow robustness, and they were twice as more accurate compared to routine phenotypic identification in our sample pool. MALDITOF systems with their accuracy and robustness offer a good identification platform for routine clinical microbiology laboratories.

scholarly journals Cytosolic Proteome Profiling of Aminoglycosides Resistant Mycobacterium tuberculosis Clinical Isolates Using MALDI-TOF/MS

2016 ◽  
Vol 7 ◽  
Author(s):  
Divakar Sharma ◽  
Manju Lata ◽  
Rananjay Singh ◽  
Nirmala Deo ◽  
Krishnamurthy Venkatesan ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Clinical Isolates ◽  
Maldi Tof Ms ◽  
Proteome Profiling ◽  
Maldi Tof ◽  
Tof Ms

Clinical and microbiological characteristics of Cryptococcus gattii isolated from China

2020 ◽  
Author(s):  
Liang Jin ◽  
Jingrong Cao ◽  
Xinying Xue ◽  
Hua Wu ◽  
Lifeng Wang ◽  
...  
Keyword(s):  
Antifungal Agents ◽  
Antifungal Susceptibility ◽  
The United States ◽  
Cryptococcus Gattii ◽  
Clinical Isolates ◽  
Strain Identification ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Significant Difference ◽  
Tof Ms

Abstract Background: Infection, even outbreak, caused by Cryptococcus gattii (C. gattii ) has been reported in Canada and the United States, but there were sparsely-reported cases of C. gattii in China. Our interest in occurrence, clinical manifestation, laboratory identification and molecular characterization of Chinese C. gattii strains leads us to this research. Methods: A total of 254 clinical isolates primarily identified as Cryptococcus neoformans (C. neoformans ) were collected. VITEK 2 compact, canavanine glycine bromothymol blue (CGB) agar and Bruker Biotyper matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) were used for strain identification. Multi-locus sequence typing (MLST) was performed for genotyping. Antifungal susceptibility test was carried out with commercial kits of both ATB fungus 3 and Yeast one. Clinical information of patients was reviewed retrospectively. Label-free proteome technique was used to quantitatively analyze the differential proteins of C. gattii. Results: Out of 254 clinical isolates, we identified eight strains as C. gattii. MLST showed genotype VGI accounted for the most (6 / 8), the other two strains were genotype VGII（VGIIa and VGIIb respectively）with 3 specific spectra of molecular weight about 4342, 8686, 9611 Dalton by MALDI-TOF MS. The minimal inhibitory concentrations (MICs) of Fluconazole with Yeast one was 2～4 times higher than that with ATB fungus 3. Higher MICs of antifungal agents were exhibited against VGII strains than against VGI strains. C. gattii genotype VGII and VGI possessed 418 and 774 specific proteins respectively. Comparative proteome analysis showed that 180 proteins were highly expressed in C. gattii VGII and 329 proteins were highly expressed in C. gattii VGI. The enrichment of differentially expressed proteins between VGII and VGI was directed to Golgi complex.Conclusions: Infection by C. gattii in China might have been underestimated because of initial mis-identification. Genotype VGI was predominant but VGII was more resistant to antifungal agents. There was significant difference in protein expression profile between VGII and VGI C. gattii.

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