scholarly journals In Vitro Activities of Terbinafine in Combination with Fluconazole, Itraconazole, Voriconazole, and Posaconazole against Clinical Isolates of Candida glabrata with Decreased Susceptibility to Azoles

2002 ◽  
Vol 40 (5) ◽  
pp. 1831-1833 ◽  
Author(s):  
S. Perea ◽  
G. Gonzalez ◽  
A. W. Fothergill ◽  
D. A. Sutton ◽  
M. G. Rinaldi
2001 ◽  
Vol 45 (4) ◽  
pp. 1174-1183 ◽  
Author(s):  
Dominique Sanglard ◽  
Francoise Ischer ◽  
Jacques Bille

ABSTRACT Candida glabrata has been often isolated from AIDS patients with oropharyngeal candidiasis treated with azole antifungal agents, especially fluconazole. We recently showed that the ATP-binding-cassette (ABC) transporter gene CgCDR1 was upregulated in C. glabrata clinical isolates resistant to azole antifungal agents (D. Sanglard, F. Ischer, D. Calabrese, P. A. Majcherczyk, and J. Bille, Antimicrob. Agents Chemother. 43:2753–2765, 1999). Deletion of CgCDR1 in C. glabrata rendered the null mutant hypersusceptible to azole derivatives and showed the importance of this gene in mediating azole resistance. We observed that wild-type C. glabrata exposed to fluconazole in a medium containing the drug at 50 μg/ml developed resistance to this agent and other azoles at a surprisingly high frequency (2 × 10−4 to 4 × 10−4). We show here that this high-frequency azole resistance (HFAR) acquired in vitro was due, at least in part, to the upregulation ofCgCDR1. The CgCDR1 deletion mutant DSY1041 could still develop HFAR but in a medium containing fluconazole at 5 μg/ml. In the HFAR strain derived from DSY1041, a distinct ABC transporter gene similar to CgCDR1, calledCgCDR2, was upregulated. This gene was slightly expressed in clinical isolates but was upregulated in strains with the HFAR phenotype. Deletion of both CgCDR1 and CgCDR2suppressed the development of HFAR in a medium containing fluconazole at 5 μg/ml, showing that both genes are important mediators of resistance to azole derivatives in C. glabrata. We also show here that the HFAR phenomenon was linked to the loss of mitochondria in C. glabrata. Mitochondrial loss could be obtained by treatment with ethidium bromide and resulted in acquisition of resistance to azole derivatives without previous exposure to these agents. Azole resistance obtained in vitro by HFAR or by agents stimulating mitochondrial loss was at least linked to the upregulation of both CgCDR1 and CgCDR2.


2005 ◽  
Vol 49 (8) ◽  
pp. 3544-3545 ◽  
Author(s):  
E. R. Oliveira ◽  
A. W. Fothergill ◽  
W. R. Kirkpatrick ◽  
B. J. Coco ◽  
T. F. Patterson ◽  
...  

ABSTRACT Combinations of caspofungin and posaconazole were evaluated by fractional inhibitory concentration index against 119 Candida glabrata isolates. Synergy was seen in 18% of all isolates and in 4% of fluconazole-resistant isolates at 48 h without evidence of antagonism. This antifungal combination may have utility against this organism.


2020 ◽  
Vol 75 (5) ◽  
pp. 1187-1193 ◽  
Author(s):  
Andrés Ceballos Garzon ◽  
Daniela Amado ◽  
Estelle Robert ◽  
Claudia M Parra Giraldo ◽  
Patrice Le Pape

Abstract Background In recent decades, Candida glabrata has emerged as a frequent cause of life-threatening fungal infection. In C. glabrata, echinocandin resistance is associated with mutations in FKS1/FKS2 (β-1,3-glucan synthase). The calmodulin/calcineurin pathway is implicated in response to antifungal stress and calcineurin gene disruption specifically reverses Fks2-mediated resistance of clinical isolates. Objectives We evaluated the impact of calmodulin inhibition by fluphenazine in two caspofungin-resistant C. glabrata isolates. Methods C. glabrata isolates were identified by ITS1/ITS4 (where ITS stands for internal transcribed spacer) sequencing and the echinocandin target FKS1/FKS2 genes were sequenced. Susceptibility testing of caspofungin in the presence of fluphenazine was performed by a modified CLSI microbroth dilution method. The effect of the fluphenazine/caspofungin combination on heat stress (37°C or 40°C), oxidative stress (0.2 and 0.4 mM menadione) and biofilm formation (polyurethane catheter) was analysed. A Galleria mellonella model using blastospores (1 × 109 cfu/mL) was developed to evaluate the impact of this combination on larval survival. Results F659del was found in the FKS2 gene of both resistant strains. In these clinical isolates, fluphenazine increased susceptibility to caspofungin and reduced their thermotolerance. Furthermore, the fluphenazine/caspofungin combination significantly impaired biofilm formation in an in vitro polyurethane catheter model. All these features participated in the increasing survival of infected G. mellonella after combination treatment in comparison with caspofungin alone. Conclusions In a repurposing strategy, our findings confirm that calmodulin could provide a relevant target in life-threatening fungal infectious diseases.


1997 ◽  
Vol 41 (11) ◽  
pp. 2576-2578 ◽  
Author(s):  
J A Karlowsky ◽  
G A Harding ◽  
S A Zelenitsky ◽  
D J Hoban ◽  
A Kabani ◽  
...  

In vitro killing by a new semisynthetic echinocandin, LY-303366, was characterized using clinical isolates of fluconazole-sensitive (Y58) and -resistant (Y180) Candida albicans as well as Candida glabrata (Y7) and Candida krusei (Y171). The 24-h kill curves for Y58 and Y180 demonstrated dose-independent killing of between 1 and 2 log10 with LY-303366 at concentrations of 0.1, 1, 10, 50, 100, and 1,000 times the MIC. Regrowth did not occur at 24 h with either C. albicans isolate at the aforementioned LY-303366 concentrations. At their MICs, LY-303366 and amphotericin B produced similar killing kinetics in cultures of Y58, Y180, Y7, and Y171, while all cultures exposed to fluconazole at its MIC demonstrated stasis or growth over 24 h.


2011 ◽  
Vol 55 (8) ◽  
pp. 3947-3949 ◽  
Author(s):  
Kelley R. Healey ◽  
Santosh K. Katiyar ◽  
Mariana Castanheira ◽  
Michael A. Pfaller ◽  
Thomas D. Edlind

ABSTRACTEchinocandins, including caspofungin (CSP) and micafungin (MCF), are highly active versusCandida glabrata(MIC of ≤0.06 μg/ml). True resistance (MIC of ≥1 μg/ml) is a rare event and strictly associated with mutations in β-1,3-glucan synthase geneFKS1orFKS2. In contrast, we show here that mutants exhibiting reduced susceptibility to CSP (CRS; MICs of 0.12 to 0.5 μg/ml) are readily selectedin vitroand, paradoxically, demonstrate increased susceptibility to MCF (MIS) ranging from 4- to 32-fold. CRS-MIS mutants were generated from all 10C. glabratastrains tested and were tentatively identified within a collection of clinical isolates. Intriguingly, sequencing and gene disruption demonstrated that CRS-MIS is Fks independent.


2021 ◽  
Vol 16 (2) ◽  
Author(s):  
Niloofar Deravi ◽  
Mobina Fathi ◽  
Seyede Nadia Tabatabaeifar ◽  
Parichehr Pooransari ◽  
Bahram Ahmadi ◽  
...  

Background: Vulvovaginal candidiasis (VVC) is the most frequent fungal disorder in healthy and normal women. Objectives: The aim of this study was to evaluate the in vitro antifungal susceptibility of clinical isolates Candida albicans and Candida glabrata, the two most common candida species in Iranian patients with VVC. Methods: One hundred and eight clinical isolates of candida, including; C. albicans (n = 77) and C. glabrata: (n = 31) were isolated from the 108 patients with VVC. The in vitro activity of caspofungin (CAS), amphotericin B (AMB), voriconazole (VRC), itraconazole (ITC), fluconazole (FLC), and nystatin (NYS) were determined according to the CLSI M27-A3 and CLSI M27-S4. Results: Our results were shown 8 (25.8 %) and 6 (7.8 %) C. glabrata and C. albicans isolates resistance to FLU, respectively. Furthermore, resistance to VRC and ITC were observed in 8.4%, and 3.7% of all isolates, and six isolates (5.6%) had intermediate MIC to CAS. Conclusions: We reported 8 (25.8 %) and 6 (7.8 %) C. glabrata and C. albicans isolates resistance to FLU, respectively. Furthermore, resistance to VRC and ITC were observed in 8.4% and 3.7% of all isolates, respectively.


2019 ◽  
Vol 12 (6) ◽  
Author(s):  
Rogelio de J. Treviño-Rangel ◽  
José F. Espinosa-Pérez ◽  
Hiram Villanueva-Lozano ◽  
Laura A. Soto-Quintana ◽  
Alexandra M. Montoya ◽  
...  

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