Susceptibility of clinical isolates of Cryptococcus neoformans to amphotericin B using time–kill methodology

2009 ◽  
Vol 64 (2) ◽  
pp. 146-151 ◽  
Author(s):  
Mara C.S.M. Pappalardo ◽  
Maria Walderez Szeszs ◽  
Marilena A. Martins ◽  
Liliana B. Baceti ◽  
Lucas X. Bonfietti ◽  
...  
Keyword(s):  
Cryptococcus Neoformans ◽  
Amphotericin B ◽  
Clinical Isolates ◽  
Time Kill

Time-Kill Curves Studies with Amphotericin B Against Cryptococcus neoformans/C. gattii Species Complex Clinical Isolates

2017 ◽  
Vol 11 (4) ◽  
pp. 158-162 ◽  
Author(s):  
Lidiane de Oliveira ◽  
Dayane Cristina Silva Santos ◽  
Marilena dos Anjos Martins ◽  
Maria Walderez Szeszs ◽  
Marcia Souza Carvalho Melhem
Keyword(s):  
Cryptococcus Neoformans ◽  
Amphotericin B ◽  
Species Complex ◽  
Clinical Isolates ◽  
Time Kill

scholarly journals In vitro susceptibilities of clinical and environmental isolates of Cryptococcus neoformans to five antifungal drugs.

1996 ◽  
Vol 40 (3) ◽  
pp. 822-824 ◽  
Author(s):  
S P Franzot ◽  
J S Hamdan
Keyword(s):  
Cryptococcus Neoformans ◽  
Amphotericin B ◽  
Clinical Laboratory ◽  
Antifungal Drugs ◽  
Clinical Isolates ◽  
National Committee ◽  
Environmental Isolates ◽  
Susceptibility Data

A total of 53 Cryptococcus neoformans strains, including clinical and environmental Brazilian isolates, were tested for their susceptibilities to amphotericin B, 5-flucytosine, ketoconazole, fluconazole, and itraconazole. The tests were performed according to the National Committee of Clinical Laboratory Standards recommendations (document M27-P). In general, there was a remarkable homogeneity of results for all strains, and comparable MICs were found for environmental and clinical isolates. This paper represents the first contribution in which susceptibility data for Brazilian C. neoformans isolates are provided.

Evaluation of amphotericin B and flucytosine in combination against Candida albicans and Cryptococcus neoformans using time-kill methodology

2001 ◽  
Vol 41 (3) ◽  
pp. 121-126 ◽  
Author(s):  
Douglas J. Keele ◽  
Veronica C. DeLallo ◽  
Russell E. Lewis ◽  
Erika J. Ernst ◽  
Michael E. Klepser
Keyword(s):  
Candida Albicans ◽  
Cryptococcus Neoformans ◽  
Amphotericin B ◽  
Time Kill

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 In Vitro Interaction of Flucytosine with Conventional and New Antifungals against Cryptococcus neoformans Clinical Isolates

2003 ◽  
Vol 47 (10) ◽  
pp. 3361-3364 ◽  
Author(s):  
Patrick Schwarz ◽  
Françoise Dromer ◽  
Olivier Lortholary ◽  
Eric Dannaoui
Keyword(s):  
Cryptococcus Neoformans ◽  
Amphotericin B ◽  
Clinical Isolates ◽  
In Vitro Interaction

ABSTRACT Combinations of flucytosine with conventional and new antifungals were evaluated in vitro against 30 clinical isolates of Cryptococcus neoformans. Synergy determined by checkerboard analysis was observed with combinations of fluconazole, itraconazole, voriconazole, amphotericin B, and caspofungin with flucytosine against 77, 60, 80, 77, and 67% of the isolates, respectively. Antagonism was never observed. Killing curves showed indifferent interactions between triazoles and flucytosine and synergy between amphotericin B and flucytosine.

scholarly journals Evaluation of Etest Method for Determining Voriconazole and Amphotericin B MICs for 162 Clinical Isolates of Cryptococcus neoformans

2003 ◽  
Vol 41 (1) ◽  
pp. 97-99 ◽  
Author(s):  
M. J. Maxwell ◽  
S. A. Messer ◽  
R. J. Hollis ◽  
D. J. Diekema ◽  
M. A. Pfaller
Keyword(s):  
Cryptococcus Neoformans ◽  
Amphotericin B ◽  
Clinical Isolates

scholarly journals Fluconazole tolerance in clinical isolates of Cryptococcus neoformans.

1997 ◽  
Vol 41 (4) ◽  
pp. 748-751 ◽  
Author(s):  
K Venkateswarlu ◽  
M Taylor ◽  
N J Manning ◽  
M G Rinaldi ◽  
S L Kelly
Keyword(s):  
Cryptococcus Neoformans ◽  
Amphotericin B ◽  
Clinical Isolates ◽  
Biochemical Basis ◽  
Low Level ◽  
Cellular Content ◽  
Low Levels ◽  
High Level ◽  
Level Resistance ◽  
Target Enzyme

Eleven isolates of Cryptococcus neoformans were investigated to determine the biochemical basis of their tolerance to fluconazole. The MICs of fluconazole for three isolates with low-level resistance were 3- to 6-fold higher than those for sensitive isolates, while the MICs for four isolates with high-level resistance were 100- to 200-fold higher than those for sensitive isolates. The level of ergosterol present in the isolates varied, and those which had relatively low levels of ergosterol were resistant to amphotericin B. Changes in the affinity of the target enzyme (sterol 14alpha-demethylase) and decreases in the cellular content of fluconazole seemed to be responsible for the resistance in isolates with low-level and high-level resistance, respectively.

scholarly journals Antifungal susceptibilities of clinical and environmental isolates of Cryptococcus neoformans in goiânia city, Goiás, Brasil

2005 ◽  
Vol 47 (5) ◽  
pp. 253-256 ◽  
Author(s):  
Lúcia Kioko Hasimoto Souza ◽  
Orionalda de Fátima Lisboa Fernandes ◽  
Cláudia Castelo Branco Artiaga Kobayashi ◽  
Xisto Sena Passos ◽  
Carolina Rodrigues Costa ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Cryptococcus Neoformans ◽  
Amphotericin B ◽  
Similar Pattern ◽  
Clinical Isolates ◽  
Broth Microdilution ◽  
Environmental Isolates ◽  
Minimal Inhibitory Concentrations ◽  
Microdilution Method ◽  
Broth Microdilution Method

We evaluated the antifungal activities of amphotericin B, fluconazole, itraconazole and voriconazole in 70 Cryptococcus neoformans strains obtained from cerebrospinal fluid from AIDS patients and 40 C. neoformans strains isolated from the environment. Four clinical isolates were identified as C. neoformans var. gattii. The susceptibility test was done using a broth microdilution method according to NCCLS M27-A2. Range minimal inhibitory concentrations (MICs) for C. neoformans clinical isolates were 0.06-1.0 µg/mL for amphotericin B, 0.125-8 µg/mL for fluconazole, 0.03-0.5 µg/mL for itraconazole and 0.03-0.25 µg/mL for voriconazole. C. neoformans environmental isolates showed range MICs 0.015-0.125 µg/mL, 0.25-2.0 µg/mL, 0.007-0.125 µg/mL and 0.03-0.25 µg/mL for amphotericin B, fluconazole, itraconazole and voriconazole respectively. The MICs results obtained from clinical and environmental isolates showed similar pattern of susceptibility and no resistance has been found in our isolates.

scholarly journals ATI-2307 Exhibits Equivalent Antifungal Activity in Cryptococcus neoformans Clinical Isolates With High and Low Fluconazole IC50

2021 ◽  
Vol 11 ◽  
Author(s):  
Elliot S. Gerlach ◽  
Sophie Altamirano ◽  
J. Marina Yoder ◽  
Tony S. Luggya ◽  
Andrew Akampurira ◽  
...  
Keyword(s):  
Cryptococcus Neoformans ◽  
Amphotericin B ◽  
Inhibitory Concentration ◽  
Antifungal Drug ◽  
Clinical Isolates ◽  
Combination Drug ◽  
Dilution Assay ◽  
Experimental Drug ◽  
The Common ◽  
Microbroth Dilution

Half maximal inhibitory concentrations (IC50) to the experimental drug ATI-2307 and complete inhibition (IC90) of the common clinically used antifungal drug amphotericin B were determined by microbroth dilution assay for a collection of 69 clinical isolates of Cryptococcus neoformans from Uganda that had high fluconazole IC50 values. The majority of the clinical isolates tested had fluconazole IC50 at or above 8 µg/mL, but were susceptible to both amphotericin B (IC90 ≤1 μg/mL) and ATI-2307 (IC50 ≤0.0312 µg/mL). No correlation between increased fluconazole minimum inhibitory concentration (MIC) and ATI-2307 or amphotericin B MIC was observed, suggesting that the cellular changes impacting fluconazole susceptibility did not impact the effectiveness of ATI-2307. Our results suggest that ATI-2307 is a promising new antifungal drug for use in the context of high fluconazole or other antifungal drug MICs and/or in combination drug therapy regimens.

Sign in / Sign up

Export Citation Format

Share Document