scholarly journals Candida duobushaemulonii: An Old But Unreported Pathogen

2020 ◽  
Vol 6 (4) ◽  
pp. 374
Author(s):  
Irene Jurado-Martín ◽  
Cristina Marcos-Arias ◽  
Esther Tamayo ◽  
Andrea Guridi ◽  
Piet W. J. de Groot ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Related Species ◽  
Antifungal Drugs ◽  
Candida Auris ◽  
Closely Related Species ◽  
Identification Methods ◽  
Phenotypic Identification ◽  
Candida Intermedia ◽  
Candida Haemulonii

Candidiasis caused by species of the Candida haemulonii complex (Candida haemulonii and Candida duobushaemulonii) and closely related species, Candida auris and Candida pseudohaemulonii are increasing. These species often show reduced susceptibility to antifungal drugs, such as azoles and amphotericin B or, less frequently, echinocandins. However, conventional phenotypic identification methods are unable to accurately differentiate these species and, therefore, their prevalence may have been underestimated. In this study, 150 isolates that were probably misidentified were reanalyzed using two novel PCR approaches. We found that one isolate previously identified in 1996 as Candida intermedia was C. duobushaemulonii, being one of the oldest isolates of this species described to date. We also found that this isolate had reduced susceptibility to fluconazole, itraconazole, and amphotericin B.

scholarly journals Assessment of Candida auris Response to Antifungal Drugs Using Time–Kill Assays and an Animal Model

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S73-S73 ◽  
Author(s):  
Ronen Ben-Ami ◽  
Liat Ashkenazi ◽  
Judith Berman ◽  
Nuphar Korolker ◽  
Anna Novikov
Keyword(s):  
Amphotericin B ◽  
Fungicidal Activity ◽  
Antifungal Drugs ◽  
Rank Test ◽  
Infection Model ◽  
Candida Auris ◽  
Fungistatic Activity ◽  
Kill Curve ◽  
Time Kill

Abstract Background Candida auris is an emerging nosocomial pathogen that is resistant to Fluconazole and variably susceptible to other systemic drug classes. Treatment with echinocandins has been recommended based on MICs in the susceptible range, but supporting in vivo data is lacking. Methods We tested the MIC of C. auris strains (n = 12) to fluconazole, voriconazole, posaconazole. anidulafungin, amphotericin B and flucytosine. Representative C. auris strains from Israel and South Africa, and a reference C. albicans strain were analysed using time–kill curve assays. Fungicidal activity was defined as reduction of ≥3 log from baseline CFU/ml. Response to caspofungin treatment was assessed in BALB/c mice immunosuppressed with cyclophosphamide and inoculated with 7 × 107C. auris cells by tail vein injection. Mice were treated from day +1 to day +7 with caspofungin (IP) at doses of 1 or 5 mg/kg and compared with sham-treated controls. Survival was assessed daily. Kaplan-Meier survival analyses were performed and treatment arms were compared using the log-rank test. Results Drug susceptibility results (MIC50 and MIC90) were: fluconazole, 64 and 128 mg/l; voriconazole, 0.5 and 24 mg/l; posaconazole, 0.5 and 27 mg/l; anidulafungin, 0.03 and 0.06 mg/l; amphotericin B, 2 and 8 mg/l; flucytosine, 0.3 and 1 mg/l. Time–kill curve analyses showed log reduction from baseline CFU concentration of −3.0 to −2.8 for fluconazole (MIC ×1), 5.6–6.1 for amphotericin B (MIC ×4) and −0.4 to −0.9 for caspofungin (MIC ×16), consistent with fungicidal activity of amphotericin B and weak fungistatic activity of caspofungin. In the mouse model, survival rate was similar with sham treatment (33%) and treatment with caspofungin 1 mg/kg/day (44%) and 5 mg/kg/day (22%), P = 0.7. Conclusion Despite generally low MIC, caspofungin has only mild fungistatic activity on C. auris and no effect on survival in a mouse infection model. Amphotericin B has fungicidal activity against C. auris. Disclosures All authors: No reported disclosures.

scholarly journals In Vitro Interaction and Killing-Kinetics of Amphotericin B Combined with Anidulafungin or Caspofungin against Candida auris

Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1333
Author(s):  
Unai Caballero ◽  
Elena Eraso ◽  
Guillermo Quindós ◽  
Nerea Jauregizar
Keyword(s):  
Amphotericin B ◽  
Antifungal Drugs ◽  
Candida Auris ◽  
Dose Requirement ◽  
Fungistatic Activity ◽  
Invasive Infections ◽  
Kill Curve ◽  
Time Kill ◽  
In Vitro Interaction

Treatment of invasive infections caused by Candida auris is challenging due to the limited therapeutic options. The combination of antifungal drugs may be an interesting and feasible approach to be investigated. The aim of this study was to examine the in vitro activity of amphotericin B in combination with anidulafungin or caspofungin against C. auris. In vitro static time–kill curve experiments were conducted for 48 h with different combinations of amphotericin B with anidulafungin or caspofungin against six blood isolates of C. auris. The antifungal activity of 0.5 mg/L of amphotericin B was limited against the six isolates of C. auris. Similarly, echinocandins alone had a negligible effect, even at the highest tested concentrations. By contrast, 1 mg/L of amphotericin B showed fungistatic activity. Synergy was rapidly achieved (8 h) with 0.5 mg/L of amphotericin B plus 2 mg/L of anidulafungin or caspofungin. These combinations lead to a sustained fungistatic effect, and the fungicidal endpoint was reached against some C. auris isolates. Additionally, ≥0.5 mg/L of either of the two echinocandins with 1 mg/L of amphotericin B resulted in fungicidal effect against all C. auris isolates. In conclusion, combinations of amphotericin B with anidulafungin or caspofungin provided greater killing with a lower dose requirement for amphotericin B compared to monotherapy, with synergistic and/or fungicidal outcomes.

scholarly journals Amphotericin B and Other Polyenes—Discovery, Clinical Use, Mode of Action and Drug Resistance

2020 ◽  
Vol 6 (4) ◽  
pp. 321
Author(s):  
Hans Carolus ◽  
Siebe Pierson ◽  
Katrien Lagrou ◽  
Patrick Van Dijck
Keyword(s):  
Drug Resistance ◽  
Amphotericin B ◽  
Mode Of Action ◽  
Fungal Infections ◽  
Resistance Mechanisms ◽  
Antifungal Drugs ◽  
Clinical Use ◽  
Candida Auris ◽  
Resistance Development ◽  
Resistant Species

Although polyenes were the first broad spectrum antifungal drugs on the market, after 70 years they are still the gold standard to treat a variety of fungal infections. Polyenes such as amphotericin B have a controversial image. They are the antifungal drug class with the broadest spectrum, resistance development is still relatively rare and fungicidal properties are extensive. Yet, they come with a significant host toxicity that limits their use. Relatively recently, the mode of action of polyenes has been revised, new mechanisms of drug resistance were discovered and emergent polyene resistant species such as Candida auris entered the picture. This review provides a short description of the history and clinical use of polyenes, and focusses on the ongoing debate concerning their mode of action, the diversity of resistance mechanisms discovered to date and the most recent trends in polyene resistance development.

scholarly journals Synergistic Activity of Minocycline and Rifampin in Combination with Antifungal Drugs against Candida auris

2021 ◽  
Author(s):  
Thea Brennan-Krohn ◽  
Liam Friar ◽  
Sarah Ditelberg ◽  
James E. Kirby
Keyword(s):  
Amphotericin B ◽  
Antibacterial Agents ◽  
Treatment Options ◽  
Multidrug Resistant ◽  
Antifungal Drugs ◽  
Synergistic Activity ◽  
Candida Auris ◽  
Healthcare Settings ◽  
Time Kill ◽  
Synergy Testing

ABSTRACTCandida auris is an emerging multidrug-resistant fungal pathogen that spreads readily in healthcare settings and has caused numerous hospital outbreaks. Very few treatment options exist for C. auris infections. We evaluated the activity of all two-drug combinations of three antifungal agents (amphotericin B, caspofungin, and voriconazole) and two antibacterial agents (minocycline and rifampin) against a collection of 10 C. auris isolates using an automated, inkjet printer-assisted checkerboard array method. Three antibacterial-antifungal combinations (amphotericin B plus rifampin, amphotericin B plus minocycline, and caspofungin plus minocycline) demonstrated synergistic activity by checkerboard array against ≥90% of strains. The two amphotericin B-containing combinations were also synergistic using the time-kill synergy testing method. Our results suggest that combinations of antifungal and antibacterial agents may provide a promising avenue for treatment of this multidrug-resistant pathogen.

Evaluation of the Synergistic Activity of Antibacterial and Antifungal Drugs against Candida auris using an Inkjet Printer-Assisted Method

2021 ◽  
Author(s):  
Thea Brennan-Krohn ◽  
Liam Friar ◽  
Sarah Ditelberg ◽  
James E. Kirby
Keyword(s):  
Amphotericin B ◽  
Antibacterial Agents ◽  
Treatment Options ◽  
Multidrug Resistant ◽  
Antifungal Drugs ◽  
Synergistic Activity ◽  
Candida Auris ◽  
Healthcare Settings ◽  
Inkjet Printer ◽  
Antibacterial And Antifungal

Candida auris is an emerging multidrug-resistant fungal pathogen that spreads readily in healthcare settings and has caused numerous hospital outbreaks. Very few treatment options exist for C. auris infections. We evaluated the activity of all two-drug combinations of three antifungal agents (amphotericin B, caspofungin, and voriconazole) and two antibacterial agents (minocycline and rifampin) against a collection of 10 C. auris isolates using an automated, inkjet printer-assisted checkerboard array method. Three antibacterial-antifungal combinations (amphotericin B plus rifampin, amphotericin B plus minocycline, and caspofungin plus minocycline) demonstrated synergistic activity by checkerboard array against ≥90% of strains with fractional inhibitory concentration index (FICI) values of 0.094 to 0.5. The two amphotericin B-containing combinations were also synergistic using the time-kill synergy testing method, with up to a 4.99 log 10 decrease in surviving yeast compared to either agent alone. Our results suggest that combinations of antifungal and antibacterial agents may provide a promising avenue for treatment of this multidrug-resistant pathogen.

scholarly journals Genomic basis of multidrug-resistance, mating, and virulence inCandida aurisand related emerging species

2018 ◽  
Author(s):  
José F. Muñoz ◽  
Lalitha Gade ◽  
Nancy A. Chow ◽  
Vladimir N. Loparev ◽  
Phalasy Juieng ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Related Species ◽  
Chromosomal Rearrangements ◽  
Copy Number Variants ◽  
Multidrug Resistant ◽  
Antifungal Drugs ◽  
Health Concern ◽  
Wall Structure ◽  
Candida Auris ◽  
Genomic Basis

AbstractCandida aurisis an emergent fungal pathogen of rising public health concern due to increasing reports of outbreaks in healthcare settings and resistance to multiple classes of antifungal drugs. While distantly related to the more common pathogensC. albicansandC. glabrata,C. aurisis closely related to three rarely observed and often multidrug-resistant species,C. haemulonii, C. duobushaemulonii and C. pseudohaemulonii. Here, we generated and analyzed near complete genome assemblies and RNA-Seq-guided gene predictions for isolates from each of the four majorC. aurisclades and forC. haemulonii, C. duobushaemulonii and C. pseudohaemulonii. Our analyses mapped seven chromosomes and revealed chromosomal rearrangements betweenC. aurisclades and related species. We found conservation of genes involved in mating and meiosis and identified bothMTLaandMTLαC. aurisisolates, suggesting the potential for mating between clades. Gene conservation analysis highlighted that many genes linked to drug resistance and virulence in other pathogenicCandidaspecies are conserved inC. aurisand related species including expanded families of transporters and lipases, as well as mutations and copy number variants inERG11that confer drug resistance. In addition, we found genetic features of the emerging species that likely underlie differences in virulence and drug response between these and otherCandidaspecies, including genes involved in cell wall structure. To begin to characterize the species-specific genes important for antifungal response, we profiled the gene expression ofC. aurisin response to voriconazole and amphotericin B and found induction of several transporters and metabolic regulators that may play a role in drug resistance. This study provides a comprehensive view of the genomic basis of drug resistance, potential for mating, and virulence in this emerging fungal clade.

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