scholarly journals Danish Whole-Genome-Sequenced Candida albicans and Candida glabrata Samples Fit into Globally Prevalent Clades

2021 ◽  
Vol 7 (11) ◽  
pp. 962
Author(s):  
Judit Szarvas ◽  
Ana Rita Rebelo ◽  
Valeria Bortolaia ◽  
Pimlapas Leekitcharoenphon ◽  
Dennis Schrøder Hansen ◽  
...  
Keyword(s):  
Population Structure ◽  
Candida Albicans ◽  
Candida Glabrata ◽  
Fungal Pathogens ◽  
Clinical Microbiology ◽  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
Antifungal Susceptibility Testing ◽  
Whole Genome ◽  
Geographical Locations

Candida albicans and Candida glabrata are opportunistic fungal pathogens with increasing incidence worldwide and higher-than-expected prevalence in Denmark. We whole-genome sequenced yeast isolates collected from Danish Clinical Microbiology Laboratories to obtain an overview of the Candida population in the country. The majority of the 30 C. albicans isolates were found to belong to three globally prevalent clades, and, with one exception, the remaining isolates were also predicted to cluster with samples from other geographical locations. Similarly, most of the eight C. glabrata isolates were predicted to be prevalent subtypes. Antifungal susceptibility testing proved all C. albicans isolates to be susceptible to both azoles and echinocandins. Two C. glabrata isolates presented azole-resistant phenotypes, yet all were susceptible to echinocandins. There is no indication of causality between population structure and resistance phenotypes for either species.

scholarly journals Evaluation of the “Dip Effect” Phenomenon in Antifungal Susceptibility Testing of Candida spp. against Echinocandins by Use of Gradient Concentration Strips

2015 ◽  
Vol 53 (11) ◽  
pp. 3654-3659 ◽  
Author(s):  
Maria Siopi ◽  
Marilena Tsala ◽  
Nikolaos Siafakas ◽  
Loukia Zerva ◽  
Joseph Meletiadis
Keyword(s):  
Candida Albicans ◽  
Candida Tropicalis ◽  
Candida Glabrata ◽  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
Antifungal Susceptibility Testing ◽  
Practical Approach ◽  
Candida Spp ◽  
Content Type ◽  
Inhibition Zones

The “dip effect” phenomenon complicates antifungal susceptibility testing with gradient concentration strips. Of 60Candidaisolates tested with the three echinocandins, this phenomenon was observed only for caspofungin with most (>90%)Candida albicans,Candida glabrata, andCandida tropicalisisolates and for isolates with CLSI MICs of ≤0.25 mg/liter. In order to facilitate MIC determination, a practical approach was developed using the inhibition zones at 32, 8, 2, and 1 mg/liter, increasing the agreement with the CLSI method >86%.

scholarly journals Flow Cytometry Antifungal Susceptibility Testing of Pathogenic Yeasts other than Candida albicans and Comparison with the NCCLS Broth Microdilution Test

2000 ◽  
Vol 44 (10) ◽  
pp. 2752-2758 ◽  
Author(s):  
Rama Ramani ◽  
Vishnu Chaturvedi
Keyword(s):  
Flow Cytometry ◽  
Candida Albicans ◽  
Amphotericin B ◽  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
Antifungal Susceptibility Testing ◽  
Broth Microdilution ◽  
Nitrogen Base ◽  
Microdilution Method ◽  
Broth Microdilution Method

ABSTRACT Candida species other than Candida albicansfrequently cause nosocomial infections in immunocompromised patients. Some of these pathogens have either variable susceptibility patterns or intrinsic resistance against common azoles. The availability of a rapid and reproducible susceptibility-testing method is likely to help in the selection of an appropriate regimen for therapy. A flow cytometry (FC) method was used in the present study for susceptibility testing ofCandida glabrata, Candida guilliermondii,Candida krusei, Candida lusitaniae,Candida parapsilosis, Candida tropicalis, andCryptococcus neoformans based on accumulation of the DNA binding dye propidium iodide (PI). The results were compared with MIC results obtained for amphotericin B and fluconazole using the NCCLS broth microdilution method (M27-A). For FC, the yeast inoculum was prepared spectrophotometrically, the drugs were diluted in either RPMI 1640 or yeast nitrogen base containing 1% dextrose, and yeast samples and drug dilutions were incubated with amphotericin B and fluconazole, respectively, for 4 to 6 h. Sodium deoxycholate and PI were added at the end of incubation, and fluorescence was measured with a FACScan flow cytometer (Becton Dickinson). The lowest drug concentration that showed a 50% increase in mean channel fluorescence compared to that of the growth control was designated the MIC. All tests were repeated once. The MICs obtained by FC for all yeast isolates except C. lusitaniae were in very good agreement (within 1 dilution) of the results of the NCCLS broth microdilution method. Paired ttest values were not statistically significant (P = 0.377 for amphotericin B; P = 0.383 for fluconazole). Exceptionally, C. lusitaniae isolates showed higher MICs (2 dilutions or more) than in the corresponding NCCLS broth microdilution method for amphotericin B. Overall, FC antifungal susceptibility testing provided rapid, reproducible results that were statistically comparable to those obtained with the NCCLS method.

scholarly journals Identification of Fungal Pathogens in Otomycosis and Their Drug Sensitivity: Our Experience

2018 ◽  
Vol 22 (04) ◽  
pp. 400-403 ◽  
Author(s):  
Khaled Ali ◽  
Mahmood Hamed ◽  
Hameda Hassan ◽  
Amira Esmail ◽  
Abeer Sheneef
Keyword(s):  
Enzymatic Activity ◽  
Candida Species ◽  
Fungal Pathogens ◽  
Antifungal Agents ◽  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
Antifungal Susceptibility Testing ◽  
Antifungal Drugs ◽  
High Recurrence Rate ◽  
Fungal Culture

Introduction Otomycosis is a common problem in otolaryngology practice. However, we usually encounter some difficulties in its treatment because many patients show resistance to antifungal agents, and present high recurrence rate. Objectives To determine the fungal pathogens that cause otomycosis as well as their susceptibility to the commonly used antifungal agents. Additionally, to discover the main reasons for antifungal resistance. Methods We conducted an experimental descriptive study on 122 patients clinically diagnosed with otomycosis from April 2016 to April 2017. Aural discharge specimens were collected for direct microscopic examination and fungal culture. In vitro antifungal susceptibility testing was performed against the commonly used antifungal drugs. We tested the isolated fungi for their enzymatic activity. Results Positive fungal infection was found in 102 samples. The most common fungal pathogens were Aspergillus and Candida species, with Aspergillus niger being the predominant isolate (51%). The antifungal susceptibility testing showed that mold isolates had the highest sensitivity to voriconazole (93.48%), while the highest resistance was to fluconazole (100%). For yeast, the highest sensitivity was to nystatin (88.24%), followed by amphotericin B (82.35%), and the highest resistance was to terbinafine (100%), followed by Itraconazole (94.12%). Filamentous fungi expressed a high enzymatic ability, making them more virulent. Conclusion The Aspergillus and Candida species are the most common fungal isolates in otomycosis. Voriconazole and Nystatin are the medications of choice for the treatment of otomycosis in our community. The high virulence of fungal pathogens is owed to their high enzymatic activity. Empirical use of antifungals should be discouraged.

scholarly journals Speciation of Candida using CHROMagar from various clinical specimens and their antifungal susceptibility pattern at a tertiary care hospital.

2020 ◽  
Vol 16 (2) ◽  
pp. 107-111
Author(s):  
Sanjana Raj Kumari ◽  
Neetu Adhikaree
Keyword(s):  
Candida Albicans ◽  
Candida Species ◽  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
Tertiary Care ◽  
Epidemiological Data ◽  
Antifungal Susceptibility Testing ◽  
Antifungal Drugs ◽  
Care Hospital ◽  
Clinical Specimens

Background: Candida albicans remains the most common and are responsible for various clinical infections ranging from mucocutaneous infection to life threatening invasive diseases. But recent epidemiological data shift from C.albicans to non albicans Candida species and also increased resistance to antifungal drugs made the scenario a serious concern. Methods: A total of 156 Candida isolates from various clinical specimens received in the department of Microbiology were taken up for the study over a period of one year i.e. from March 2019 to February 2020. The Candida were grown on Sabouraud dextrose agar to be  evaluated for colony  appearance, macroscopic examination, Gram staining, germ tube, urea hydrolysis etc. The Candida isolates were speciated by using CHROMagar medium. Antifungal susceptibility testing was performed as recommended by Clinical and Laboratory Standards Institute (CLSI) M44-A document. Results: The isolation of non albicans Candida (54.5%) predominated over Candida albicans (45.5%). Non albicans Candida isolated were Candida tropcalis 40(25.6%), Candida krusei 21(13.4%), Candida glabrata 17(10.8%) and Candida dublinensis 07(4.4%) each. Candida species were all susceptible to Amphotericin B, followed by fluconazole (67.4%), miconazole (51.9%) and ketoconazole (22.5%). Conclusions: The accurate species identification of Candida is important for the treatment because not all species respond to the same treatment and also because of the increasing antifungal resistance. CHROMagar is a convenient and rapid method of identification of Candida species specially in resource limited poor settings.   Keywords: antifungal susceptibility testing; Candida albicans; CHROMagar; non albicans Candida

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