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
1996 ◽  
Vol 40 (3) ◽  
pp. 822-824 ◽  
Author(s):  
S P Franzot ◽  
J S Hamdan

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.


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

2001 ◽  
Vol 43 (5) ◽  
pp. 267-270 ◽  
Author(s):  
Sydney Hartz ALVES ◽  
Loiva T. OLIVEIRA ◽  
Jane M. COSTA ◽  
Irina LUBECK ◽  
Agnes Kiesling CASALI ◽  
...  

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.


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 ◽  
...  

2003 ◽  
Vol 47 (10) ◽  
pp. 3361-3364 ◽  
Author(s):  
Patrick Schwarz ◽  
Françoise Dromer ◽  
Olivier Lortholary ◽  
Eric Dannaoui

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.


1997 ◽  
Vol 41 (4) ◽  
pp. 748-751 ◽  
Author(s):  
K Venkateswarlu ◽  
M Taylor ◽  
N J Manning ◽  
M G Rinaldi ◽  
S L Kelly

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.


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 ◽  
...  

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.


Author(s):  
Elliot S. Gerlach ◽  
Sophie Altamirano ◽  
J. Marina Yoder ◽  
Tony S. Luggya ◽  
Andrew Akampurira ◽  
...  

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.


2005 ◽  
Vol 49 (2) ◽  
pp. 512-517 ◽  
Author(s):  
Po-Ren Hsueh ◽  
Yeu-Jun Lau ◽  
Yin-Ching Chuang ◽  
Jen-Hsien Wan ◽  
Wen-Kuei Huang ◽  
...  

ABSTRACT The susceptibilities of nonduplicate isolates to six antifungal agents were determined for 391 blood isolates of seven Candida species, 70 clinical isolates (from blood or cerebrospinal fluid) of Cryptococcus neoformans, and 96 clinical isolates of four Aspergillus species, which were collected in seven different hospitals in Taiwan (as part of the 2003 program of the study group Surveillance of Multicenter Antimicrobial Resistance in Taiwan). All isolates of Candida species other than C. glabrata and C. krusei were susceptible to fluconazole. Among the 59 C. glabrata isolates, 16 (27%) were not susceptible to fluconazole, and all were dose-dependently susceptible or resistant to itraconazole. For three (5.1%) C. glabrata isolates, voriconazole MICs were 2 to 4 μg/ml, and for all other Candida species isolates, voriconazole MICs were ≤0.5 μg/ml. The proportions of isolates for which amphotericin B MICs were ≥2 μg/ml were 100% (3 isolates) for C. krusei, 11% (23 of 207 isolates) for Candida albicans, 3.0% (2 of 67 isolates) for Candida tropicalis, 20% (12 of 59 isolates) for C. glabrata, and 0% for both Candida parapsilosis and Candida lusitaniae. For three (4%) Cryptococcus neoformans isolates, fluconazole MICs were ≥16 μg/ml, and two (3%) isolates were not inhibited by 1 μg of amphotericin B/ml. For four (4.2%) of the Aspergillus isolates, itraconazole MICs were 8 μg/ml. Aspergillus flavus was less susceptible to amphotericin B, with the MICs at which 50% (1 μg/ml) and 90% (2 μg/ml) nsrsid417869\delrsid7301351 of isolates were inhibited being twofold greater than those for Aspergillus fumigatus and Aspergillus niger. All Aspergillus isolates were inhibited by ≤1 μg of voriconazole/ml, including isolates with increased resistance to amphotericin B and itraconazole. This study revealed the emergence in Taiwan of decreased susceptibilities of Candida species to amphotericin B and of C. neoformans to fluconazole and amphotericin B. Voriconazole was the most potent agent against the fungal isolates tested, including fluconazole- and amphotericin B-nonsusceptible strains.


Mycoses ◽  
2019 ◽  
Vol 62 (9) ◽  
pp. 818-825 ◽  
Author(s):  
Trieu Phan Hai ◽  
Anh Duong Van ◽  
Nguyen Thi Thuy Ngan ◽  
Le Thanh Hoang Nhat ◽  
Nguyen Phu Huong Lan ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document