Systemic fungal diseases and antifungal resistance represent a serious problem in human medicine and con-tribute to increased patient mortality. The most common causes of these diseases are opportunistic yeasts of the genus Candida. C. albicansis considered to be the main pathogen, together with C. glabrata, C. tropicalis, C. par-apsilosis, and C.krusei. Azole antifungals predominate in the treatment of the systemic mycoses. For antifungal re-sistance in Candidaspp. some genes and their mutations are responsible, the genes ERG11, CDR1, CDR2and MDR1being considered the most important. The main target of azole antifungals is the process of ergosterol syn-thesis. Due to ergosterol crucial functions and its unique structural properties, the synthesis of ergosterol and its individual steps represent the target of most clinically available antifungals. The biofilm appears to be a signifi-cant virulence factor of the yeast Candidaspp. It allows hematogenous dissemination of cells, prevents the effect of antifungals on all cells during treatment and leads to a high level of antimicrobial resistance. The antifungal re-sistance in candidiasis often has a multifactorial origin, which must be considered in the treatment of systemic mycoses and in the development of new antifungals.
- MeSH
- antifungální látky chemie farmakologie terapeutické užití MeSH
- azoly farmakologie terapeutické užití MeSH
- biofilmy účinky léků MeSH
- Candida patogenita účinky léků MeSH
- ergosterol biosyntéza MeSH
- faktory virulence MeSH
- flukonazol farmakologie terapeutické užití MeSH
- fungální léková rezistence MeSH
- itrakonazol farmakologie terapeutické užití MeSH
- kandidóza * farmakoterapie mikrobiologie MeSH
- lidé MeSH
- vorikonazol farmakologie terapeutické užití MeSH
- Check Tag
- lidé MeSH
- MeSH
- antifungální látky farmakologie terapeutické užití MeSH
- dospělí MeSH
- flukonazol farmakologie terapeutické užití MeSH
- kryptokoková meningitida * diagnóza farmakoterapie komplikace MeSH
- lidé MeSH
- senioři MeSH
- výsledek terapie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- Publikační typ
- kazuistiky MeSH
Due to the increase in fungal resistance to existing drugs, a need exists to search for new antifungals. This study aimed to evaluate the antifungal activity of α, β, and δ-damascone and inclusion complexes with β-cyclodextrin against different Candida spp. The inclusion complex of β-damascone was prepared by the co-evaporation method using three molar proportions (1:1; 2:1; 3:1 (βDA-βCD)) and analyzed using Fourier transform infrared spectroscopy (FTIR). Standard Candida albicans (CA INCQS 40,006), Candida krusei (CK INCQS 40,095), and Candida tropicalis (CT INCQS 40,042) strains were used to evaluate antifungal activity. The substances were tested individually or in association with fluconazole (FCZ). The IC50 and cell viability curve constructions were performed using the microdilution method. The minimum fungicidal concentration (MFC) was determined by the subculture method in a solid medium. The α, β, and δ-DA isolated or in combination with fluconazole (FCZ) showed significant antifungal activity. β-damascone showed effective complexation in the three molar proportions assayed; however, none of the inclusion complexes was demonstrated clinically significant effects against the fungal tested. Then, all compounds have shown promising antifungal activities; however, in vivo assays are necessary to have therapeutical application in the future.
In recent years, increased rates of yeast infections in humans and animals have been recognized worldwide. Since animals may represent a source of yeast infections for humans, knowing the antifungal susceptibility profile of yeast isolates from milk and evaluating their pathogenic potential would be of great medical importance. Therefore, the aim of this survey was to study yeast diversity in milk samples, analyze the hemolytic and phospholipase activities of isolates and determine minimal inhibition concentration (MIC) for fluconazole, voriconazole and flucytosine. Out of 66 yeast isolates obtained from 910 individual raw milk samples from subclinically infected cows, 26 different yeast species were determined based on sequencing of the D1/D2 and ITS regions. Among them, Pichia kudriavzevii (formerly known as Candida krusei), Kluyveromyces marxianus (formerly known as Candida kefyr) and Debaryomyces hansenii (formerly known as Candida famata) were the most commonly identified. Hemolysin and/or phospholipase activity was observed in 66.7% of isolates. The elevated MIC for fluconazole was determined in 16 isolates from 11 species. The findings of this study demonstrate that yeast isolates from raw milk have the potential to express virulence attributes such as hemolysin and phospholipase, and additionally, some of these strains showed elevated MIC to fluconazole or to flucytosine.LAY SUMMARY: We identified 66 yeast isolates, including 26 different yeast species from 910 individual milk samples. Our results indicate that individual milk samples may serve as a source of yeasts with the potential to trigger infection and may have reduced sensitivity to tested antifungal agents.
Aim: This work studied the impact of the quorum-sensing molecule, farnesol (FAR), on fluconazole (FLC)-resistant Candida albicans isolate CY 1123 compared with the susceptible standard strain C. albicans SC5314. The genes encoding efflux pumps belonging to the ATP-binding cassette (ABC) and major facilitator superfamilies, together with overexpression or point mutation of the ERG11 gene, are the main resistance mechanisms to azole antifungal drugs. Results: The upregulation of genes coding for CDR1, CDR2, and MDR1 were confirmed by qPCR with respect to the housekeeping gene ACT1 in the resistant strain. The contribution of the ERG11 gene was also observed. Markedly, increased pump activity (Cdr1 and/or Cdr2) in the CY 1123 strain was confirmed using diS-C3(3) assay. However, the addition of FAR to the yeasts diminished the difference in staining levels between the SC5314 and CY 1123 strains, demonstrating the concentration-dependent character that could be caused by an effective modulation of Cdr pumps. FAR (60 and 100 μM) was also able to decrease the minimal inhibitory concentrations (MIC50), denoting the inhibition of planktonic cells by 50%, from 8 to 4 μg/mL of FLC when the resistant strain CY 1123 was not cultivated with FLC. However, when it was exposed to 64 μg/mL of FLC, the MIC50 shifted from 64 to 8 μg/mL. Conclusion: Besides the many other effects of FAR on eukaryotic and prokaryotic cells, it also affects ABC efflux transporters, resulting in changes in resistance to azoles in C. albicans isolates. However, this effect is dependent on FAR concentrations.
- MeSH
- ABC transportéry metabolismus MeSH
- antifungální látky farmakologie MeSH
- biologický transport účinky léků MeSH
- Candida albicans účinky léků metabolismus MeSH
- farnesol farmakologie MeSH
- flukonazol farmakologie MeSH
- fungální léková rezistence účinky léků MeSH
- fungální proteiny metabolismus MeSH
- membránové transportní proteiny metabolismus MeSH
- mikrobiální testy citlivosti metody MeSH
- Publikační typ
- časopisecké články MeSH
Due to the increasing number of Candida albicans' infections and the resistance of this pathogenic fungus to drugs, new therapeutic strategies are sought. One of such strategies may be the use of static magnetic field (SMF). C. albicans cultures were subjected to static magnetic field of the induction 0.5 T in the presence of fluconazole and amphotericin B. We identified a reduction of C. albicans hyphal length. Also, a statistically significant additional effect on the viability of C. albicans was revealed when SMF was combined with the antimycotic drug amphotericin B. The synergistic effect of this antimycotic and SMF may be due to the fact that amphotericin B binds to ergosterol in plasma membrane and SMF similarly to MF could influence domain orientation in plasma membrane (PM).
- MeSH
- amfotericin B farmakologie MeSH
- antifungální látky farmakologie MeSH
- Candida albicans účinky léků růst a vývoj MeSH
- flukonazol farmakologie MeSH
- hyfy účinky léků růst a vývoj MeSH
- magnetické pole * MeSH
- mikrobiální testy citlivosti MeSH
- mikrobiální viabilita účinky léků MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- antifungální látky * farmakologie klasifikace terapeutické užití MeSH
- flukonazol aplikace a dávkování farmakologie terapeutické užití MeSH
- itrakonazol aplikace a dávkování farmakologie terapeutické užití MeSH
- lékové interakce MeSH
- lidé MeSH
- nežádoucí účinky léčiv MeSH
- terbinafin aplikace a dávkování farmakologie terapeutické užití MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
Farnesol (FAR) has already demonstrated an inhibitory effect on Candida albicans biofilm. The aim of this work was to determine the effectiveness of externally added FAR in combination with fluconazole (FLC) on Candida albicans biofilm and on regulation of the ergosterol genes ERG20, ERG9, and ERG11. The effectiveness of compounds was determined by MTT assay and evaluated by the minimal inhibitory concentrations reducing a sessile biofilm to 50% activity (0.5 μg/mL and 200 μmol/L for FLC and FAR, respectively). These concentrations as well as 30 and 100 μmol/L FAR were selected for a study of the effectiveness of the FAR/FLC combination. The reduction in biofilm robustness mainly caused by the presence of 200 μmol/L FAR-alone or in combination with FLC-was accompanied by a significant inhibition of the yeast-to-hyphae transition that was observed by light microscopy and CLSM. Results from qRT-PCR indicated that while 30 μmol/L FAR only slightly regulated the expression of all 3 genes in the 48-h biofilm, the presence of 200 μmol/L FAR downregulated all the tested genes. However, the addition of 0.5 μg/mL of FLC to the samples with 200 μmol/L FAR restored the downregulation of the ERG20 and ERG11 genes to the control level. Moreover, the gene ERG9 was slightly upregulated. In summary, FAR acted via multiple effects on the C. albicans biofilm, but only a higher concentration of FAR proved to be effective.
- MeSH
- antifungální látky farmakologie MeSH
- biofilmy účinky léků růst a vývoj MeSH
- Candida albicans účinky léků růst a vývoj MeSH
- ergosterol genetika metabolismus MeSH
- farnesol farmakologie MeSH
- flukonazol farmakologie MeSH
- geny hub genetika MeSH
- hyfy účinky léků MeSH
- metabolické sítě a dráhy účinky léků MeSH
- mikrobiální testy citlivosti MeSH
- regulace genové exprese u hub účinky léků MeSH
- synergismus léků MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- Publikační typ
- časopisecké články MeSH
We compared the potency of four derivatives of the antimicrobial peptide halictine-2 against six Candida species. Observed activity was peptide and species specific. Halictines rapidly permeabilized cell membranes and caused the leakage of cytosolic components. Their killing potential was enhanced by the commercial antimicrobial agent octenidine dihydrochloride. The effect on C. glabrata cells did not depend on the activity of Cdr pumps, but was influenced by their lipid composition. The pre-treatment of cells with myriocin, an inhibitor of sphingolipid synthesis, enhanced the peptides' activity, whereas pre-treatment with terbinafine and fluconazole, inhibitors of sterol synthesis, significantly weakened their efficacy. The killing efficacy of peptides increased in combination with amphotericin B. Thus the mode of action of halictines is likely to depend on the plasma-membrane sterols, which might explain the observed differences among the tested Candida species.
- MeSH
- amfotericin B chemie farmakologie MeSH
- antifungální látky chemie farmakologie MeSH
- antiinfekční látky chemie farmakologie MeSH
- buněčná membrána účinky léků MeSH
- Candida účinky léků MeSH
- flukonazol chemie farmakologie MeSH
- kyseliny mastné mononenasycené chemie farmakologie MeSH
- lipidy chemie MeSH
- mikrobiální testy citlivosti metody MeSH
- naftaleny chemie farmakologie MeSH
- peptidy chemie farmakologie MeSH
- pyridiny chemie farmakologie MeSH
- steroly chemie farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
With emerging fungal infections and developing resistance, there is a need for understanding the mechanisms of resistance as well as its clinical impact while planning the treatment strategies. Several approaches could be taken to overcome the problems arising from the management of fungal diseases. Besides the discovery of novel effective agents, one realistic alternative is to enhance the activity of existing agents. This strategy could be achieved by combining existing antifungal agents with other bioactive substances with known activity profiles (combination therapy). Azole antifungals are the most frequently used class of substances used to treat fungal infections. Fluconazole is often the first choice for antifungal treatment. The aim of this work was to study potential synergy between azoles and 1,4-dihydropyridine-2,3,5-tricarboxylate (termed derivative H) in order to control fungal infections. This article points out the synergy between azoles and newly synthesized derivative H in order to fight fungal infections. Experiments confirmed the role of derivative H as substrate/inhibitor of fungal transporter Cdr1p relating to increased sensitivity to fluconazole. These findings, plus decreased expression of ERG11, are responsible for the synergistic effect.
- MeSH
- ABC transportéry antagonisté a inhibitory genetika MeSH
- antifungální látky chemická syntéza farmakologie terapeutické užití MeSH
- Candida albicans účinky léků genetika MeSH
- dihydropyridiny chemická syntéza farmakologie terapeutické užití MeSH
- flukonazol farmakologie terapeutické užití MeSH
- fungální léková rezistence účinky léků MeSH
- fungální proteiny antagonisté a inhibitory genetika MeSH
- kandidóza farmakoterapie MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- mutace MeSH
- regulace genové exprese u hub účinky léků MeSH
- sterol-14-demethylasa genetika MeSH
- synergismus léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
