scholarly journals Impact of Brief Exposure to Drugs with Antifungal Properties on the Susceptibility of Oral Candida dubliniensis Isolates to Lysozyme and Lactoferrin

2018 ◽  
Vol 27 (6) ◽  
pp. 523-530 ◽  
Author(s):  
Arjuna Nishantha B. Ellepola ◽  
Ranil Samantha Dassanayake ◽  
Ziauddin Khan
Keyword(s):  
Amphotericin B ◽  
Inhibitory Concentration ◽  
Oral Candidiasis ◽  
Therapeutic Agents ◽  
Candida Dubliniensis ◽  
Antifungal Effect ◽  
Candida Infections ◽  
Oral Candida

Objective: Lysozyme and lactoferrin have anti-candidal activity. Candida dubliniensis is associated with oral candidiasis. Candida infections are managed with nystatin, amphotericin B, caspofungin, ketoconazole, fluconazole, and chlorhexidine. Candida species undergo a brief exposure to therapeutic agents in the mouth. There is no data on the influence of limited exposure to antimycotics on the sensitivity of C. dubliniensis to lactoferrin and lysozyme. Hence, this study observed the changes in the sensitivity of C. dubliniensis to anti-candidal action of lactoferrin and lysozyme after transitory exposure to sub-lethal concentrations of antifungals. Materials and Methods: After determination of the minimum inhibitory concentration (MIC), 20 C. dubliniensis isolates were exposed to twice the concentration of MIC of nystatin, amphotericin B, caspofungin, ketoconazole, fluconazole, and chlorhexidine for 1 h. Drugs were removed by dilution and thereafter the susceptibility of these isolates to lysozyme and lactoferrin was determined by colony-forming unit quantification assay. Results: Exposure of C. dubliniensis to nystatin, amphotericin B, caspofungin, ketoconazole, fluconazole, and chlorhexidine resulted in an increase in susceptibility to lysozyme by 9.45, 30.82, 30.04, 50.64, 55.60, and 50.18%, respectively (p < 0.05 to p < 0.001). Exposure of C. dubliniensis to nystatin, amphotericin B, caspofungin, ketoconazole, fluconazole, and chlorhexidine resulted in an increase in susceptibility to lactoferrin by 13.54, 16.43, 17.58, 19.60, 21.32, and 18.73, respectively (p < 0.05 to p < 0.001). Conclusion: Brief exposure to nystatin, amphotericin B, caspofungin, ketoconazole, fluconazole, and chlorhexidine enhances the antifungal effect of lysozyme and lactoferrin on C. dubliniensis isolates in vitro.

scholarly journals In vitro Post-Antifungal Effect of Posaconazole and Its Impact on Adhesion-Related Traits and Hemolysin Production of Oral Candida dubliniensis Isolates

2019 ◽  
Vol 28 (6) ◽  
pp. 552-558
Author(s):  
Arjuna Nishantha Bandara Ellepola ◽  
Ranil Samantha Dassanayake ◽  
Ziauddin Khan
Keyword(s):  
Oral Candidiasis ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Candida Dubliniensis ◽  
In Vitro Assays ◽  
Drug Induced ◽  
Antifungal Effect ◽  
Buccal Epithelial Cells ◽  
Oral Candida

Objective: Candidal adherence to denture acrylic surfaces (DAS) and oral buccal epithelial cells (BEC), formation of candidal germ tubes (GT), candidal cell surface hydrophobicity (CSH), and hemolysin production are important pathogenic traits of Candida. The antifungal drug-induced post-antifungal effect (PAFE) also impacts the virulence of Candida. Candida dubliniensis isolates are associated with the causation of oral candidiasis which could be managed with posaconazole. Thus far there is no evidence on posaconazole-induced PAFE and its impact on adhesion-related attributes and production of hemolysin by C. dubliniensis isolates. Hence, the PAFE, adhesion to DAS and BEC, formation of GT, CSH, and hemolysin production of 20 oral C. dubliniensis isolates after brief exposure to posaconazole was ascertained. Materials and Methods: The PAFE, adherence to DAS and BEC, formation of GT, candidal CSH, and hemolysin production were investigated by hitherto described in vitro assays. Results: The mean PAFE (h) induced by posaconazole on C. dubliniensis isolates was 1.66. Exposure to posaconazole suppressed the ability of C. dubliniensis to adhere to DAS, BEC, formation of candidal GT, candidal CSH and to produce hemolysin by a reduction of 44, 33, 34, 36, and 15% (p < 0.005 to p < 0.001), respectively. Conclusion: Exposure of C. dubliniensis isolates to posaconazole for a brief period induced an antimycotic impact by subduing its growth in addition to suppressing pathogenic adherence-associated attributes, as well as production of hemolysin.

scholarly journals Antifungal drug susceptibilities of oral Candida dubliniensis isolates from human immunodeficiency virus (HIV)-infected and non-HIV-infected subjects and generation of stable fluconazole-resistant derivatives in vitro.

1997 ◽  
Vol 41 (3) ◽  
pp. 617-623 ◽  
Author(s):  
G P Moran ◽  
D J Sullivan ◽  
M C Henman ◽  
C E McCreary ◽  
B J Harrington ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Amphotericin B ◽  
Oral Candidiasis ◽  
Antifungal Drugs ◽  
Candida Dubliniensis ◽  
Fluconazole Resistance ◽  
Immunodeficiency Virus ◽  
Fluconazole Resistant ◽  
Hiv Negative

Candida dubliniensis is a recently described species of Candida associated with oral candidiasis in human immunodeficiency virus (HIV)-infected individuals. Nineteen oral isolates of C. dubliniensis recovered from 10 HIV-positive and 4 HIV-negative individuals and one vaginal isolate from an additional HIV-negative subject were assessed for fluconazole susceptibility by broth microdilution (BMD), hyphal elongation assessment, and Etest. The susceptibilities of these 20 isolates to itraconazole and amphotericin B and of 10 isolates to ketoconazole were also determined by BMD only. Sixteen of the C. dubliniensis isolates were susceptible to fluconazole (MIC range, 0.125 to 1.0 microgram ml-1), and four (recovered from two AIDS patients) were fluconazole resistant (MIC range, 8 to 32 micrograms ml-1). Fluconazole susceptibility data obtained by hyphal elongation assessment correlated well with results obtained by BMD, but the corresponding Etest MIC results were one to four times higher. All of the isolates tested were found to be sensitive to itraconazole, ketoconazole, and amphotericin B. Sequential exposure of two fluconazole-sensitive (MIC, 0.5 microgram ml-1) C. dubliniensis isolates to increasing concentrations of fluconazole in agar medium resulted in the recovery of derivatives which expressed a stable fluconazole-resistant phenotype (BMD-determined MIC range, 16 to 64 micrograms ml-1), even after a minimum of 10 consecutive subcultures on drug-free medium and following prolonged storage at -70 degrees C. The clonal relationship between the parental isolates and their respective fluconazole-resistant derivatives was confirmed by genomic DNA fingerprinting and karyotype analysis. The results of this study demonstrate that C. dubliniensis is inherently susceptible to commonly used antifungal drugs, that fluconazole resistance does occur in clinical isolates, and that stable fluconazole resistance can be readily induced in vitro following exposure to the drug.

scholarly journals Reduction in the in vitro sensitivity oF Drechslera tritici-repentis, isolated from wheat, to strobilurin and triazole fungicides

2017 ◽  
Vol 43 (1) ◽  
pp. 20-25
Author(s):  
Rosane Baldiga Tonin ◽  
Erlei Melo Reis ◽  
Aveline Avozani
Keyword(s):  
Inhibitory Concentration ◽  
In Vitro Sensitivity ◽  
Randomized Design ◽  
Inhibition Data ◽  
Ic50 Values ◽  
Control Failure ◽  
Quinone Outside Inhibitors ◽  
Completely Randomized Design

ABSTRACT Reports of failure in the chemical control of wheat yellow leaf spot led to determination of the sensitivity of Drechslera tritici-repentis (Dtr) to the fungicides quinone outside inhibitors (QoIs) and demethylation inhibitors (DMIs). The IC50 was obtained for strobilurins (azoxystrobin, kresoxim-methyl, picoxystrobin and pyraclostrobin) and for triazoles (cyproconazole, epoxiconazole, propiconazole, prothioconazole and tebuconazole), using five Dtr isolates. Seven concentrations of the fungicides were tested in the bioassay: 0.00; 0.01; 0.10; 1.00; 10:00 and 20.00 and 40.00 mg/L active ingredient (a.i.). Assays consisted of completely randomized design and four replicates. Each experiment was performed twice, using the average of the two tests for statistical analysis. The percentage inhibition data for conidial germination (QoIs) and for mycelial growth (DMIs) were subjected to logarithmic regression analysis, calculating the 50% inhibitory concentration (IC50) based on the generated equation. There was a reduction in the sensitivity of Dtr isolates to strobilurins. IC50 values ranged from 0.58 to > 40.00 mg/L. The lowest sensitivity of isolates was detected for azoxystrobin, kresoxim-methyl, picoxystrobin and trifloxystrobin. Pyraclostrobin was most efficient, showing IC50 between 0.58 and 1.03 mg/L. The IC50 ranged from 0.35 to 1.37 mg/L for epoxiconazole, from 0.49 to 1.28 mg/L for propiconazole and from 1.41 to 2.34 mg/L for tebuconazole. Prothioconazole was most potent, showing IC50 between 0.09 and 0.21 mg/L. The hypothesis that the control failure can be attributed to the reduced Dtr sensitivity to the fungicides QoIs and DMIs was confirmed.

scholarly journals In vitro activities of Traganum nudatum and Mentha pulegium extracts combined with amphotericin B against Candida albicans in production of hydrolytic enzymes

2020 ◽  
Author(s):  
Ikram Tefiani ◽  
Sidi Mohammed Lahbib Seddiki ◽  
Moustafa Yassine Mahdad
Keyword(s):  
Candida Albicans ◽  
Minimum Inhibitory Concentration ◽  
Amphotericin B ◽  
Inhibitory Concentration ◽  
Culture Media ◽  
Hydrolytic Enzymes ◽  
Normal Flora ◽  
Mentha Pulegium ◽  
Hydrolytic Activities

Background and Purpose: Candida albicans is an important microorganism in the normal flora of a healthy subject; however, it has an expedient pathogenic character that induces hydrolytic virulence. Regarding this, the present study aimed to find an in vitro alternative that could reduce the virulence of this yeast. Materials and Methods: For the purpose of the study, the effect of amphotericin B (AmB) combined with the extract of Traganum nudatum (E1) or Mentha pulegium (E2) was evaluated against the hydrolytic activities of esterase, protease, and phospholipase. This effect was determined by calculating the minimum inhibitory concentration (MIC), used to adjust the extract/AmB mixtures in culture media. Results: The evaluated Pz values, which corresponded to the different enzymatic activities, showed a decrease in the hydrolytic activities of C. albicans strains after the addition of E1/AmB and E2/AmB combinations at descending concentrations (lower than the obtained MICs). Conclusion: Based on the findings, it would be possible to reduce the pathogenesis of this species without destabilizing the balance of the flora.

scholarly journals In Vitro Antifungal Combination of Flucytosine with Amphotericin B, Voriconazole, or Micafungin against Candida auris Shows No Antagonism

2019 ◽  
Vol 63 (12) ◽  
Author(s):  
A. L. Bidaud ◽  
F. Botterel ◽  
A. Chowdhary ◽  
E. Dannaoui
Keyword(s):  
Amphotericin B ◽  
Inhibitory Concentration ◽  
Geometric Mean ◽  
Multidrug Resistant ◽  
Candida Auris ◽  
Content Type ◽  
Hospital Acquired Infections ◽  
Resistant Mutants ◽  
Hospital Acquired

ABSTRACT Candida auris is an emerging, multidrug-resistant pathogen responsible for invasive hospital-acquired infections. Flucytosine is an effective anti-Candida species drug, but which cannot be used as a monotherapy because of the risk of development of resistant mutants during treatment. It is, therefore, noteworthy to test possible combinations with flucytosine that may have a synergistic interaction. In this study, we determined the in vitro interaction between flucytosine and amphotericin B, micafungin, or voriconazole. These combinations have been tested against 15 C. auris isolates. The MIC ranges (geometric mean [Gmean]) of flucytosine, amphotericin B, micafungin, and voriconazole were 0.125 to 1 μg/ml (0.42 μg/ml), 0.25 to 1 μg/ml (0.66 μg/ml), 0.125 to 0.5 μg/ml (0.3 μg/ml), and 0.03 to 4 μg/ml (1.05 μg/ml), respectively. When tested in combination, indifferent interactions were mostly observed with fractional inhibitory concentration index values from 0.5 to 1, 0.31 to 1.01, and 0.5 to 1.06 for the combinations of flucytosine with amphotericin B, micafungin, and voriconazole, respectively. A synergy was observed for the strain CBS 10913 from Japan. No antagonism was observed for any combination. The combination of flucytosine with amphotericin B or micafungin may be relevant for the treatment of C. auris infections.

scholarly journals In VitroActivities of a Wide Panel of Antifungal Drugs against Various Scopulariopsis and Microascus Species

2015 ◽  
Vol 59 (9) ◽  
pp. 5827-5829 ◽  
Author(s):  
Magdalena Skóra ◽  
Małgorzata Bulanda ◽  
Tomasz Jagielski
Keyword(s):  
Amphotericin B ◽  
Effective Concentration ◽  
Antifungal Drugs ◽  
Antifungal Effect ◽  
Content Type ◽  
Minimal Effective Concentration

ABSTRACTThein vitroactivities of 11 antifungal drugs against 68ScopulariopsisandMicroascusstrains were investigated. Amphotericin B, 5-fluorocytosine, fluconazole, itraconazole, ketoconazole, miconazole, posaconazole, voriconazole, and ciclopirox showed no or poor antifungal effect. The best activities were exhibited by terbinafine and caspofungin, where the MIC and MEC (minimal effective concentration) ranges were 0.0313 to >16 μg/ml and 0.125 to 16 μg/ml, respectively. The MIC and MEC modes were both 1 µg/ml for terbinafine and caspofungin; the MIC50and MEC50were 1 µg/ml for both drugs, whereas the MIC90and MEC90were 4 µg/ml and 16 µg/ml, respectively.

scholarly journals Impact of brief and sequential exposure to nystatin, amphotericin B, ketoconazole, and fluconazole in modulating adhesion traits of oral Candida dubliniensis isolates

2014 ◽  
Vol 7 (2) ◽  
pp. 149-157 ◽  
Author(s):  
Arjuna N.B. Ellepola ◽  
Bobby K. Joseph ◽  
Lakshman P. Samaranayake ◽  
H.M.H.N. Bandara ◽  
Zia U. Khan
Keyword(s):  
Amphotericin B ◽  
Candida Dubliniensis ◽  
Oral Candida

scholarly journals Eugenol and Isoeugenol In Association with Antifungal Against Cryptococcus neoformans

2017 ◽  
Vol 9 (4) ◽  
Author(s):  
Pinheiro L. S. ◽  
Sousa J. P. ◽  
Sousa J. P. ◽  
Barreto N. A. ◽  
Dantas T B ◽  
...  
Keyword(s):  
Cryptococcus Neoformans ◽  
Amphotericin B ◽  
Inhibitory Concentration ◽  
Synergistic Effects ◽  
Antagonistic Effect ◽  
Antifungal Drugs ◽  
Antifungal Effect ◽  
Beneficial Effects ◽  
Combined Use ◽  
Antifungal Effects

The antifungal therapy combined is used in clinical practice of several mycoses as it may increase the efficacy of the treatment. The use of natural products (phytochemicals) in combination with conventional antifungal drugs has been related to beneficial effects, mainly synergistic effects. The aim of this study was to evaluate the effect of the combined use of eugenol / isoeugenol, compounds with recognized antimicrobial activity, in association with antifungal amphotericin B against strains of Cryptococcus neoformans. The combined antifungal effect were be determined from the Fraction Inhibitory Concentration index - checkerboard technique. The results obtained in this study showed that eugenol in combination with amphotericin B had antagonistic effect against the strains of C. neoformans, LM 615 and INCQS 40221 (FIC index 6.0 and 4.0), respectively. The combination of the isoeugenol and amphotericin B also showed antagonistic effects for both the LM 615 strain and INCQS 40221 (FIC index 6.0 and 5.0), respectively. This study contributed to the understanding of the antifungal effects of the association of phenylpropanoids (eugenol / isoeugenol) with amphotericin B. Further studies are needed to evaluate and compare the effects of the association of these phytochemicals with other conventional antifungal drugs used against C. neoformans.

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