scholarly journals Testing of the In Vitro Susceptibilities of Madurella mycetomatis to Six Antifungal Agents by Using the Sensititre System in Comparison with a Viability-Based 2,3-Bis(2-Methoxy-4-Nitro-5-Sulfophenyl)-5- [(Phenylamino)Carbonyl]-2H-Tetrazolium Hydroxide (XTT) Assay and a Modified NCCLS Method

2005 ◽  
Vol 49 (4) ◽  
pp. 1364-1368 ◽  
Author(s):  
Wendy W. J. van de Sande ◽  
Ad Luijendijk ◽  
Abdalla O. A. Ahmed ◽  
Irma A. J. M. Bakker-Woudenberg ◽  
Alex van Belkum
Keyword(s):  
Amphotericin B ◽  
Antifungal Agents ◽  
Clinical Isolates ◽  
Therapeutic Management ◽  
Xtt Assay ◽  
Routine Testing ◽  
Antifungal Activities ◽  
Madurella Mycetomatis ◽  
Relevant Range

ABSTRACT The in vitro susceptibilities of 36 clinical isolates of Madurella mycetomatis, the prime agent of eumycetoma in Africa, to ketoconazole, itraconazole, fluconazole, voriconazole, amphotericin B, and flucytosine were determined by the Sensititre YeastOne system. This system appeared to be a rapid and easy test, and by use of hyphal suspensions it generated results comparable to those of a modified NCCLS method. After 10 days of incubation, the antifungal activities of ketoconazole (MIC at which 90% of isolates were inhibited [MIC90], 0.125 μg/ml), itraconazole (MIC90, 0.064 μg/ml), and voriconazole (MIC90, 0.125 μg/ml) appeared superior to those of fluconazole (MIC90, 128 μg/ml) and amphotericin B (MIC90, 1 μg/ml), with MICs in the clinically relevant range. All isolates were resistant to flucytosine (all MICs above 64 μg/ml). Based on the relatively broad range of MICs obtained for the antifungal agents, routine testing of M. mycetomatis isolates for susceptibility to antifungal agents seems to be relevant to adequate therapeutic management.

scholarly journals In Vitro Activities of New and Conventional Antifungal Agents against Clinical Scedosporium Isolates

2002 ◽  
Vol 46 (1) ◽  
pp. 62-68 ◽  
Author(s):  
Joseph Meletiadis ◽  
Jacques F. G. M. Meis ◽  
Johan W. Mouton ◽  
Juan Luis Rodriquez-Tudela ◽  
J. Peter Donnelly ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Antifungal Agents ◽  
Clinical Isolates ◽  
Cross Resistance ◽  
Scedosporium Apiospermum ◽  
Distribution Analysis ◽  
Lipid Formulation ◽  
Antifungal Activities ◽  
Growth Inhibitory

ABSTRACT The susceptibilities of 13 clinical isolates of Scedosporium apiospermum and 55 clinical isolates of S. prolificans to new and conventional drugs belonging to three different classes of antifungal agents, the azoles (miconazole, itraconazole, voriconazole, UR-9825, posaconazole), the polyenes (amphotericin B, nystatin and liposomal nystatin), and allylamines (terbinafine), were studied by use of proposed standard M38-P of NCCLS. Low growth-inhibitory antifungal activities were found in vitro for most of the drugs tested against S. prolificans isolates, with the MICs at which 90% of isolates are inhibited (MIC90s) being >8 μg/ml; the MIC90s of voriconazole and UR-9825, however, were 4 μg/ml. S. apiospermum isolates were more susceptible in vitro, with the highest activity exhibited by voriconazole (MIC90s, 0.5 μg/ml), followed by miconazole (MIC90s, 1 μg/ml), UR-9825 and posaconazole (MIC90s, 2 μg/ml), and itraconazole (MIC90s, 4 μg/ml). The MICs of terbinafine, amphotericin B, and the two formulations of nystatin (for which no statistically significant differences in antifungal activities were found for the two species) for S. apiospermum isolates were high. Cross-resistance was observed among all the azoles except posaconazole and among all the polyenes except the lipid formulation. A distribution analysis was performed with the MICs of each drug and for each species. Bimodal and skewed MIC distributions were obtained, and cutoffs indicating the borders of different MIC subpopulations of the distributions were determined on the basis of the normal plot technique. These cutoffs were in many cases reproducible between 48 and 72 h.

scholarly journals In Vitro Susceptibilities of Madurella mycetomatis to Itraconazole and Amphotericin B Assessed by a Modified NCCLS Method and a Viability-Based 2,3-Bis(2-Methoxy-4-Nitro-5- Sulfophenyl)-5-[(Phenylamino)Carbonyl]-2H- Tetrazolium Hydroxide (XTT) Assay

2004 ◽  
Vol 48 (7) ◽  
pp. 2742-2746 ◽  
Author(s):  
Abdalla O. A. Ahmed ◽  
Wendy W. J. van de Sande ◽  
Wim van Vianen ◽  
Alex van Belkum ◽  
Ahmed H. Fahal ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Xtt Assay ◽  
Madurella Mycetomatis ◽  
Visual Reading

ABSTRACT Susceptibilities of Madurella mycetomatis against amphotericin B and itraconazole in vitro were determined by protocols based on NCCLS guidelines (visual reading) and a 2,3-bis (2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide (XTT) assay for fungal viability. The XTT assay was reproducible and sensitive for both antifungals. Itraconazole (MIC at which 50% of the isolates tested are inhibited [MIC50]) of 0.06 to 0.13 mg/liter) was superior to amphotericin B (MIC50 of 0.5 to 1.0 mg/liter).

scholarly journals In Vitro Interactions between Antifungals and Immunosuppressants against Aspergillus fumigatus Isolates from Transplant and Nontransplant Patients

2004 ◽  
Vol 48 (12) ◽  
pp. 4922-4925 ◽  
Author(s):  
William J. Steinbach ◽  
Nina Singh ◽  
Jackie L. Miller ◽  
Daniel K. Benjamin ◽  
Wiley A. Schell ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Aspergillus Fumigatus ◽  
Amphotericin B ◽  
Calcineurin Inhibitor ◽  
Antifungal Agents ◽  
Clinical Isolates ◽  
Transplant Recipients ◽  
In Vitro Interactions

ABSTRACT We performed in vitro antifungal checkerboard testing on 12 Aspergillus fumigatus clinical isolates (6 transplant recipients and 6 nontransplant patients) with three antifungal agents (amphotericin B, voriconazole, and caspofungin) and three immunosuppressants (FK506, cyclosporine, and rapamycin). We were not able to detect a difference in calcineurin inhibitor antifungal activity against isolates from transplant recipients and nontransplant patients.

scholarly journals In Vitro Susceptibilities of 217 Clinical Isolates of Zygomycetes to Conventional and New Antifungal Agents

2007 ◽  
Vol 51 (7) ◽  
pp. 2587-2590 ◽  
Author(s):  
Nikolaos G. Almyroudis ◽  
Deanna A. Sutton ◽  
Annette W. Fothergill ◽  
Michael G. Rinaldi ◽  
Shimon Kusne
Keyword(s):  
Amphotericin B ◽  
Clinical Efficacy ◽  
Antifungal Agents ◽  
Vitro Activity ◽  
Clinical Isolates ◽  
In Vitro Activity ◽  
Cunninghamella Bertholletiae

ABSTRACT We evaluated the in vitro susceptibilities of 217 zygomycetes to amphotericin B, ketoconazole, fluconazole, itraconazole, voriconazole, posaconazole, caspofungin, and flucytosine. The significant in vitro activity of posaconazole against several species appears to support its reported clinical efficacy. Decreased susceptibility to amphotericin B was noted with Cunninghamella bertholletiae.

scholarly journals Scopulariopsis brevicaulis, a Fungal Pathogen Resistant to Broad-Spectrum Antifungal Agents

2003 ◽  
Vol 47 (7) ◽  
pp. 2339-2341 ◽  
Author(s):  
Manuel Cuenca-Estrella ◽  
Alicia Gomez-Lopez ◽  
Emilia Mellado ◽  
Maria J. Buitrago ◽  
Araceli Monzón ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Broad Spectrum ◽  
Fungal Pathogen ◽  
Antifungal Agents ◽  
Antifungal Susceptibility ◽  
Clinical Isolates ◽  
Geometric Means ◽  
Scopulariopsis Brevicaulis

ABSTRACT The antifungal susceptibility results for 32 clinical isolates of Scopulariopsis brevicaulis are presented. Flucytosine and itraconazole were inactive in vitro, and MICs of amphotericin B, voriconazole, and terbinafine for all isolates were high, with geometric means of 13, 25.8, and 14.4 μg/ml, respectively.

scholarly journals In vitro susceptibility to antifungal agents of clinical and environmental Cryptococcus neoformans isolated in Southern of Brazil

2001 ◽  
Vol 43 (5) ◽  
pp. 267-270 ◽  
Author(s):  
Sydney Hartz ALVES ◽  
Loiva T. OLIVEIRA ◽  
Jane M. COSTA ◽  
Irina LUBECK ◽  
Agnes Kiesling CASALI ◽  
...  
Keyword(s):  
Cryptococcus Neoformans ◽  
Amphotericin B ◽  
Antifungal Agents ◽  
Susceptibility Testing ◽  
Clinical Isolates ◽  
Environmental Isolates ◽  
Aids Patients ◽  
In Vitro Susceptibility ◽  
Minimal Inhibitory Concentrations

The purpose of the present study was to compare the susceptibility to four antifungal agents of 69 Cryptococcus neoformans strains isolated from AIDS patients with that of 13 C. neoformans strains isolated from the environment. Based on the NCCLS M27-A methodology the Minimal Inhibitory Concentrations (MICs) obtained for amphotericin B, itraconazole and ketoconazole were very similar for clinical and environmental isolates. Clinical isolates were less susceptible to fluconazole than environmental isolates. The significance of these findings and aspects concerning the importance, role and difficulties of C. neoformans susceptibility testing are also discussed.

scholarly journals Effect of antifungal agents, lysozyme and human antimicrobial peptide LL-37 on clinical Candida isolates with high biofilm production

2020 ◽  
Author(s):  
Yi-Chun Chen ◽  
Fang-Ju Chen ◽  
Chen-Hsiang Lee
Keyword(s):  
Amphotericin B ◽  
Biofilm Formation ◽  
Antifungal Agents ◽  
Synergistic Effects ◽  
Antifungal Drugs ◽  
Planktonic Cells ◽  
Xtt Assay ◽  
Biofilm Production ◽  
Visual Reading

Introduction. Candida species can form biofilms on tissues and medical devices, making them less susceptible to antifungal agents. Hypothesis/Gap Statement. Antifungal combination may be an effective strategy to fight against Candida biofilm. Aim. In this study, we investigated the in vitro activity of fluconazole, caspofungin and amphotericin B, alone and in combination, against 17 clinical Candida tropicalis and 6 Candida parapsilosis isolates with high biofilm formation. We also tested LL-37 and lysozyme for anti-biofilm activity against a selected C. tropicalis isolate. Methodology. Candida biofilms were prepared using the 96-well plate-based method. The minimum biofilm eradication concentrations were determined for single and combined antifungal drugs. The activity of LL-37 and lysozyme was determined by visual reading for planktonic cells and using the XTT assay for biofilms. Results. Under biofilm conditions, fluconazole plus caspofungin showed synergistic effects against 60.9% (14 of 23) of the tested isolates, including 70.6% of C. tropicalis [fractional inhibitory concentration index (FICI), 0.26–1.03] and 33.3% of C. parapsilosis (FICI, 0.04–2.03) isolates. Using this combination, no antagonism was observed. Amphotericin B plus caspofungin showed no effects against 78.3% (18 of 23) of the tested isolates. Amphotericin B plus fluconazole showed no effects against 65.2% (15 of 23) of the tested isolates and may have led to antagonism against 2 C. tropicalis and 2 C. parapsilosis isolates. LL-37 and lysozyme had no effect on biofilms of the selected C. tropicalis isolate. Conclusions. We found that fluconazole plus caspofungin led to a synergistic effect against C. tropicalis and C. parapsilosis biofilms. The efficacy of the antifungal combination therapies of the proposed schemes against biofilm-associated Candida infections requires careful and constant evaluation.

scholarly journals In Vitro Activities of 10 Combinations of Antifungal Agents against the Multiresistant Pathogen Scopulariopsis brevicaulis

2006 ◽  
Vol 50 (6) ◽  
pp. 2248-2250 ◽  
Author(s):  
Manuel Cuenca-Estrella ◽  
Alicia Gomez-Lopez ◽  
Maria J. Buitrago ◽  
Emilia Mellado ◽  
Guillermo Garcia-Effron ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Antifungal Agents ◽  
Clinical Isolates ◽  
Scopulariopsis Brevicaulis

ABSTRACT The activities of 10 combinations of antifungal agents against 25 clinical isolates of Scopulariopsis brevicaulis were tested by the checkerboard technique. An average indifferent effect was detected for all combinations. Synergy was observed for some isolates and combinations, particularly with posaconazole-terbinafine (68% of strains), amphotericin B-caspofungin (60%), and posaconazole-caspofungin (48%).

scholarly journals In Vitro Activities of Ravuconazole and Voriconazole Compared with Those of Four Approved Systemic Antifungal Agents against 6,970 Clinical Isolates of Candida spp

2002 ◽  
Vol 46 (6) ◽  
pp. 1723-1727 ◽  
Author(s):  
M. A. Pfaller ◽  
S. A. Messer ◽  
R. J. Hollis ◽  
R. N. Jones ◽  
D. J. Diekema
Keyword(s):  
Candida Albicans ◽  
Amphotericin B ◽  
Antifungal Agents ◽  
Vitro Activity ◽  
Clinical Isolates ◽  
In Vitro Activity ◽  
Candida Spp ◽  
Medical Centers ◽  
Dose Dependent

ABSTRACT The in vitro activities of ravuconazole and voriconazole were compared with those of amphotericin B, flucytosine (5FC), itraconazole, and fluconazole against 6,970 isolates of Candida spp. obtained from over 200 medical centers worldwide. Both ravuconazole and voriconazole were very active against all Candida spp. (MIC at which 90% of the isolates tested are inhibited [MIC90], 0.25 μg/ml; 98% of MICs were ≤1 μg/ml); however, a decrease in the activities of both of these agents was noted among isolates that were susceptible-dose dependent (fluconazole MIC, 16 to 32 μg/ml) and resistant (MIC, ≥ 64 μg/ml) to fluconazole. Candida albicans was the most susceptible species (MIC90 of both ravuconazole and voriconazole, 0.03 μg/ml), and C. glabrata was the least susceptible species (MIC90, 1 to 2 μg/ml). Ravuconazole and voriconazole were each more active in vitro than amphotericin B, 5FC, itraconazole, and fluconazole against all Candida spp. and were the only agents with good in vitro activity against C. krusei. These results provide further evidence for the spectrum and potency of ravuconazole and voriconazole against a large and geographically diverse collection of Candida spp.

scholarly journals Antifungal Activities of Posaconazole, Ravuconazole, and Voriconazole Compared to Those of Itraconazole and Amphotericin B against 239 Clinical Isolates of Aspergillus spp. and Other Filamentous Fungi: Report from SENTRY Antimicrobial Surveillance Program, 2000

2002 ◽  
Vol 46 (4) ◽  
pp. 1032-1037 ◽  
Author(s):  
M. A. Pfaller ◽  
S. A. Messer ◽  
R. J. Hollis ◽  
R. N. Jones
Keyword(s):  
Amphotericin B ◽  
Filamentous Fungi ◽  
Antifungal Agents ◽  
Clinical Laboratory ◽  
The United States ◽  
Clinical Isolates ◽  
National Committee ◽  
Surveillance Program ◽  
In Vitro Susceptibility

ABSTRACT Posaconazole, ravuconazole, and voriconazole are new triazole derivatives that possess potent, broad-spectrum antifungal activity. We evaluated the in vitro activity of these investigational triazoles compared with that of itraconazole and amphotericin B against 239 clinical isolates of filamentous fungi from the SENTRY Program, including Aspergillus spp. (198 isolates), Fusarium spp. (7 isolates), Penicillium spp. (19 isolates), Rhizopus spp. (4 isolates), Mucor spp. (2 isolates), and miscellaneous species (9 isolates). The isolates were obtained from 16 different medical centers in the United States and Canada between January and December 2000. In vitro susceptibility testing was performed using the microdilution broth method outlined in the National Committee for Clinical Laboratory Standards M38-P document. Overall, posaconazole was the most active compound, inhibiting 94% of isolates at a MIC of ≤1 μg/ml, followed by voriconazole (91%), amphotericin B (89%), ravuconazole (88%), and itraconazole (70%). All three new triazoles demonstrated excellent activity (MIC, ≤1 μg/ml) against Aspergillus spp. (114 Aspergillus fumigatus, 22 Aspergillus niger, 13 Aspergillus flavus, 9 Aspergillus versicolor, 8 Aspergillus terreus, and 32 Aspergillus spp.): posaconazole (98%), voriconazole (98%), ravuconazole (92%), amphotericin B (89%), and itraconazole (72%). None of the triazoles were active against Fusarium spp. (MIC at which 50% of the isolates tested were inhibited [MIC50], >8 μg/ml) or Mucor spp. (MIC50, >8 μg/ml). Posaconazole and ravuconazole were more active than voriconazole against Rhizopus spp. (MIC50, 1 to 2 μg/ml versus >8 μg/ml, respectively). Based on these results, all three new triazoles exhibited promising activity against Aspergillus spp. and other less commonly encountered isolates of filamentous fungi. The clinical value of these in vitro data remains to be seen, and in vitro-in vivo correlation is needed for both new and established antifungal agents. Surveillance efforts should be expanded in order to monitor the spectrum of filamentous fungal pathogens and their in vitro susceptibility as these new antifungal agents are introduced into clinical use.

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