Antifungal susceptibility pattern and biofilm-related genes expression in planktonic and biofilm cells of Candida parapsilosis species complex

Abstract

Background and Purpose: Candida parapsilosis complex isolates are mainly responsible for nosocomial catheter-related infection in immunocompromised patients. Biofilm formation is regarded as one of the most pertinent key virulence factors in the development of these emerging infections. The present study aimed to compare in vitro antifungal susceptibility patterns and biofilm-related genes expression ratio in planktonic and biofilm’s cells of clinically C. parapsilosis complex isolates.Materials and Methods: The current study was conducted on a number of 17 clinical C. parapsilosis complex (10 C. parapsilosis sensu stricto, 5 C. orthopsilosis, and 2 C. metapsilosis). The antifungal susceptibility patterns of amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, and caspofungin in planktonic and biofilm forms were closely examined using CLSI M27-A3 broth microdilution method. The expression levels of biofilm-related genes (BCR1, EFG1, and FKS1) were evaluated in planktonic and biofilm’s cells using Real-time polymerase chain reaction (PCR) technique.Results: The obtained results indicated that all C. parapsilosis complex isolates were able to produce high and moderate amounts of biofilm forms. In addition, the sessile minimum inhibitory concentrations were reported to be high for fluconazole (≥ 64 μg/ml), itraconazole, voriconazole, and posaconazole (≥ 16 μg/ml), as compared to planktonic minimum inhibitory concentrations. Moreover, a significant difference was observed between antifungal susceptibility patterns for all azole antifungal agents (P<0.05). Furthermore, the BCR1 overexpression was considered significant in biofilms with regard to planktonic cells in C. parapsilosis species complex (P=0.002).Conclusion: C. parapsilosis complex isolates were found susceptible to most of the tested antifungal drugs, while biofilms demonstrated a noticeable resistant to azoles. The marked discrepancy noted in antifungal susceptibility patterns among these species should be highlighted to achieve effective therapeutic treatment.

Candida parapsilosis Colony Morphotype Forecasts Biofilm Formation of Clinical Isolates

“…However, tests with the three groups of isolates (LBF, IBF, and HBF), reflecting a wide range—from negligible to high quantities of biomass—of biofilm-formation capacity on polystyrol, and six commonly used azole-, echinocandin-, and polyene antifungal agents did not reveal any such correlation. Observed MIC values were similar to those reported previously by others [ 44 , 45 , 46 , 47 ], and also, no remarkable differences were observed between inocula prepared from young or matured cells (as found in biofilms). Therefore, we conclude that the drug susceptibility data obtained with the standard EUCAST protocol do not seem to generate predictive information toward the biofilm-formation capacity of clinical isolates.…”

Molecular Investigation of Etiologic Agents Causing Vulvovaginal Candidiasis

“…In this study, routine mycological methods and DNA sequencing were used to identify yeast isolates. It's proved that sequencing the D1/D2 or ITS regions is an accurate approach for definitive identification of pathogenic yeast species, particularly the C. glabrata (17,20), and the C. parapsilosis complexes (21). The phylogenetic tree was built using the sequences of the D1/D2 region of different Candida strains and indicated the creation of distinct branches for Candida species.…”

Chemical composition, anti-fungal and cytotoxic effects of Ferula macrecolea essential oil against Candida albicans resistant and sensitive strains

“…The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of F. macrecolea essential oil against Candida isolates were determined by the broth-microdilution method based on the Clinical and Laboratory Standards Institute (CLSI) instructions (14,15). In this test, using Sabouraud Dextrose Broth (SDB) (Merck, Germany) and fungal suspension with 0.5 McFarland turbidity, different concentrations of essential oils were evaluated in 96-well plates.…”