scholarly journals In vitro susceptibility of Cryptococcus neoformans isolates to five antifungal drugs using a colorimetric system and the reference microbroth method

2000 ◽  
Vol 45 (5) ◽  
pp. 645-649 ◽  
Author(s):  
O. Lopez-Jodra
2000 ◽  
Vol 38 (8) ◽  
pp. 2949-2954 ◽  
Author(s):  
Joseph Meletiadis ◽  
Jacques F. G. M. Meis ◽  
Johan W. Mouton ◽  
J. Peter Donnelly ◽  
Paul E. Verweij

The susceptibility of 30 clinical isolates belonging to six different species of filamentous fungi (Aspergillus fumigatus, Aspergillus flavus, Scedosporium prolificans, Scedosporium apiospermum, Fusarium solani, and Fusarium oxysporum) was tested against six antifungal drugs (miconazole, voriconazole, itraconazole, UR9825, terbinafine, and amphotericin B) with the microdilution method recommended by the National Committee for Clinical Laboratory Standards (NCCLS) (M38-P). The MICs were compared with the MICs obtained by a colorimetric method measuring the reduction of the dye 3-(4,5-dimethyl-2-thiazyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) to formazan by viable fungi. The levels of agreement between the two methods were 96 and 92% for MIC-0 (clear wells) and MIC-1 (75% growth reduction), respectively. The levels of agreement were always higher for Aspergillus spp. (97% ± 2.5%), followed byScedosporium spp. (87% ± 10.3%) and Fusariumspp. (78% ± 7.8%). The NCCLS method was more reproducible than the MTT method: 98 versus 95% for MIC-0 and 97 versus 90% for MIC-1. However, the percentage of hyphal growth as determined visually by the NCCLS method showed several discrepancies when they were compared with the percentages of MTT reduction. A new simplified assay that incorporates the dye MTT with the initial inoculum and in which the fungi are incubated with the dye for 48 h or more was developed, showing comparable levels of agreement and reproducibility with the other two methods. Furthermore, the new assay was easier to perform and more sensitive than the MTT method.


1998 ◽  
Vol 42 (2) ◽  
pp. 471-472 ◽  
Author(s):  
M. Hong Nguyen ◽  
Christine Y. Yu

ABSTRACT In vitro susceptibility testing for 50 clinical isolates of fluconazole-susceptible or -resistant Cryptococcus neoformans was performed with itraconazole and voriconazole. Voriconazole was more potent than itraconazole for fluconazole-susceptible isolates and as potent as itraconazole for fluconazole-susceptible dose-dependent isolates and for fluconazole-resistant isolates. For fluconazole-resistant isolates, the voriconazole and itraconazole MICs ranged from 1 to 2 μg/ml.


Mycoses ◽  
2011 ◽  
Vol 54 (5) ◽  
pp. e583-e589 ◽  
Author(s):  
M. R. Shivaprakash ◽  
Erik Geertsen ◽  
Arunaloke Chakrabarti ◽  
Johan W. Mouton ◽  
Jacques F. Meis

2020 ◽  
Vol 23 (5) ◽  
pp. 918-922 ◽  
Author(s):  
Darby Roberts ◽  
Henry Van T. Cotter ◽  
Marc Cubeta ◽  
Brian C. Gilger

Mycoses ◽  
2020 ◽  
Vol 63 (12) ◽  
pp. 1341-1351
Author(s):  
Patrícia Helena Grizante Barião ◽  
Ludmilla Tonani ◽  
Tiago Alexandre Cocio ◽  
Roberto Martinez ◽  
Érika Nascimento ◽  
...  

2006 ◽  
Vol 5 (10) ◽  
pp. 1705-1712 ◽  
Author(s):  
S. Arunmozhi Balajee ◽  
David Nickle ◽  
Janos Varga ◽  
Kieren A. Marr

ABSTRACT Aspergillus fumigatus has been understood to be the most common cause of invasive aspergillosis (IA) in all epidemiological surveys. However, recent studies have uncovered a large degree of genetic heterogeneity between isolates morphologically identified as A. fumigatus, leading to the description of a new species, Aspergillus lentulus. Here, we examined the genetic diversity of clinical isolates identified as A. fumigatus using restriction enzyme polymorphism analysis and sequence-based identification. Analysis of 50 clinical isolates from geographically diverse locations recorded the presence of at least three distinct species: A. lentulus, Aspergillus udagawae, and A. fumigatus. In vitro, A. lentulus isolates demonstrated decreased susceptibility to antifungal drugs currently used for IA, including amphotericin B, voriconazole, and caspofungin; A. udagawae isolates demonstrated decreased in vitro susceptibility to amphotericin B. Results of the present study demonstrate that current phenotypic methods to identify fungi do not differentiate between genetically distinct species in the A. fumigatus group. Differential antifungal susceptibilities of these species may account for some of the reported poor outcomes of therapy in clinical studies.


2006 ◽  
Vol 66 (3) ◽  
pp. 939-944 ◽  
Author(s):  
E. L. Ribeiro ◽  
M. L. Scroferneker ◽  
M. S. Cavalhaes ◽  
C. C. Campos ◽  
G. M. Nagato ◽  
...  

The aim of this article is to characterize the biological aspects of oral strains of C. albicans in children with Down's syndrome. These yeasts were analyzed as to their macromorphological and enzymatic aspects and were tested as to their in vitro susceptibility to antifungal drugs using broth microdilution to determine the minimum inhibitory concentration (MIC). The morphotyping revealed that all oral C. albicans isolates from children with Down's syndrome promoted the formation of fringes regardless of size, while the control group presented smaller fringes. All oral C. albicans strains produced proteinase, but those with phospholipolytic activity showed greater enzyme capacity in the test group. In vitro susceptibility showed that all oral C. albicans isolates were sensitive to the drugs used.


2003 ◽  
Vol 98 (6) ◽  
pp. 839-841 ◽  
Author(s):  
Orionalda de FL Fernandes ◽  
Xisto S Passos ◽  
Lúcia KH Souza ◽  
André TB Miranda ◽  
Carlos Henrique PV Cerqueira ◽  
...  

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