scholarly journals In Vitro Antifungal Activity of Micafungin (FK463) against Dimorphic Fungi: Comparison of Yeast-Like and Mycelial Forms

2003 ◽  
Vol 47 (4) ◽  
pp. 1376-1381 ◽  
Author(s):  
Toru Nakai ◽  
Jun Uno ◽  
Fumiaki Ikeda ◽  
Shuichi Tawara ◽  
Kazuko Nishimura ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Amphotericin B ◽  
Growth Form ◽  
Paracoccidioides Brasiliensis ◽  
Penicillium Marneffei ◽  
Apparent Difference ◽  
Dimorphic Fungus ◽  
Mycelial Form ◽  
Dimorphic Fungi

ABSTRACT The characteristics of in vitro micafungin (FK463) antifungal activity against six species of dimorphic fungi were investigated in accordance with the NCCLS M27-A microdilution methods. MICs of micafungin, amphotericin B, itraconazole, and fluconazole for Histoplasma capsulatum var. capsulatum, Blastomyces dermatitidis, Paracoccidioides brasiliensis, Penicillium marneffei, and Sporothrix schenckii were determined both for the yeast-like form and mycelial form. Coccidioides immitis was tested only in its mycelial form. We have clearly demonstrated that the in vitro activity of micafungin depends considerably on the growth form of dimorphic fungi. Micafungin exhibited potent activity against the mycelial forms of H. capsulatum, B. dermatitidis, and C. immitis (MIC range, 0.0078 to 0.0625 μg/ml), while it was very weakly active against their yeast-like forms (MIC range, 32 to >64 μg/ml). Micafungin was also more active against the mycelial forms than the yeast-like forms of Paracoccidioides brasiliensis, Penicillium marneffei, and S. schenckii. The MICs of amphotericin B were 2 to 5 dilutions lower for the mycelial forms than for the yeast-like forms of B. dermatitidis and Paracoccidioides brasiliensis. There was no apparent difference in the activity of itraconazole between the two forms. The MICs of fluconazole for the yeast-like forms were generally lower than those for the mycelial forms, and considerably so for B. dermatitidis. These results suggest that the growth form employed in antifungal susceptibility testing of dimorphic fungi can considerably influence the interpretation of results. At present, it cannot be judged whether micafungin has clinical usefulness for dimorphic fungus infections, since for most fungi it remains uncertain which growth form correlates better with therapeutic outcome. However, the results of this study warrant further investigations of micafungin as a therapeutic agent for infections caused by dimorphic fungi.

Synthesis, in vitro antifungal activity and mechanism of action of four sterol hydrazone analogues against the dimorphic fungus Paracoccidioides brasiliensis

Steroids ◽  
2011 ◽  
Vol 76 (10-11) ◽  
pp. 1069-1081 ◽  
Author(s):  
Gonzalo Visbal ◽  
Gioconda San-Blas ◽  
Alexis Maldonado ◽  
Álvaro Álvarez-Aular ◽  
Mario V. Capparelli ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Mechanism Of Action ◽  
Paracoccidioides Brasiliensis ◽  
Dimorphic Fungus ◽  
In Vitro Antifungal Activity

scholarly journals Radiometric detection of metabolic activity of Paracoccidioides brasiliensis and its susceptibility to amphotericin B and diethylstilbestrol

1987 ◽  
Vol 29 (5) ◽  
pp. 289-294 ◽  
Author(s):  
Edwaldo E. Camargo ◽  
Maria K. Sato ◽  
Gilda M. B. Del Negro ◽  
Carlos da Silva Lacaz
Keyword(s):  
Amphotericin B ◽  
Metabolic Activity ◽  
Paracoccidioides Brasiliensis ◽  
Systemic Disease ◽  
South American ◽  
Dimorphic Fungus ◽  
Radiometric Detection ◽  
South American Blastomycosis ◽  
Low Incidence

Paracoccidioidomycosis (South American blastomycosis) is a systemic disease, strikingly more frequent in males, caused by the dimorphic fungus Paracoccidioides brasiliensis. A radiometric assay system has been applied to study the metabolic activity and the effect of drugs on this fungus "in vitro". The Y form of the yeast, grown in liquid Sabouraud medium was inoculated into sterile reaction vials containing the 6B aerobic medium along with 2.0 μCi of 14C-substrates. Control vials, prepared in the same way, contained autoclaved fungi. To study the effects of amphotericin B (AB) (0.1 and 10 μg/ml) and diethylstilbestrol (DSB) (1.0, 5.0 and 10 μg/ml) extra controls with live fungi and no drug were used. All vials were incubated at 35°C and metabolism measured daily with a Bactec instrument. 14CO2 production by P. brasiliensis was slow and could be followed for as long as 50 days. AB at 10mg/ml and DSB at 5 μg/ml inhibited the metabolism and had a cidal effect on this fungus. The results with DSB might explain the low incidence of the disease in females. This technique shows promise for studying metabolic pathways, investi gating more convenient 14C-substrates to expedite radiometric detection and for monitoring the effects of other drugs and factors on the metabolism of P. brasiliensis "in vitro".

scholarly journals In vitro antifungal activity of miltefosine and levamisole: their impact on ergosterol biosynthesis and cell permeability of dimorphic fungi

2015 ◽  
Vol 119 (4) ◽  
pp. 962-969 ◽  
Author(s):  
R.S.N. Brilhante ◽  
E.P. Caetano ◽  
R.A.C. Lima ◽  
D.S.C.M. Castelo Branco ◽  
R. Serpa ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Cell Permeability ◽  
Ergosterol Biosynthesis ◽  
Dimorphic Fungi ◽  
In Vitro Antifungal Activity

scholarly journals In Vitro and In Vivo Antifungal Activity of AmBisome Compared to Conventional Amphotericin B and Fluconazole against Candida auris

2021 ◽  
Author(s):  
Janet Herrada ◽  
Ahmed Gamal ◽  
Lisa Long ◽  
Sonia P. Sanchez ◽  
Thomas S. McCormick ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Amphotericin B ◽  
Kidney Tissue ◽  
Treated Group ◽  
Untreated Group ◽  
Candida Auris ◽  
Fungal Burden ◽  
In Vivo Antifungal Activity

Antifungal activity of AmBisome against Candida auris was determined in vitro and in vivo. AmBisome showed MIC50 and MIC90 values of 1 and 2 μg/mL, respectively. Unlike conventional amphotericin B, significant in vivo efficacy was observed in the AmBisome 7.5 mg/kg -treated group in survival and reduction of kidney tissue fungal burden compared to the untreated group. Our data shows that AmBisome shows significant antifungal activity against C. auris in vitro as well as in vivo.

scholarly journals In Vitro Activities of Voriconazole, Itraconazole, and Amphotericin B against Blastomyces dermatitidis,Coccidioides immitis, and Histoplasma capsulatum

2000 ◽  
Vol 44 (6) ◽  
pp. 1734-1736 ◽  
Author(s):  
Ren-Kai Li ◽  
Meral A. Ciblak ◽  
Nicole Nordoff ◽  
Lester Pasarell ◽  
David W. Warnock ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Histoplasma Capsulatum ◽  
Clinical Laboratory ◽  
Lethal Effect ◽  
Blastomyces Dermatitidis ◽  
National Committee ◽  
Human Pathogens ◽  
Coccidioides Immitis ◽  
Dimorphic Fungi

ABSTRACT The in vitro activity of voriconazole was compared to those of itraconazole and amphotericin B against the mold forms of 304 isolates of three dimorphic fungi, Blastomyces dermatitidis,Coccidioides immitis, and Histoplasma capsulatum. MICs were determined by a broth microdilution adaptation of the National Committee for Clinical Laboratory Standards M27-A procedure. RPMI 1640 medium was used for tests with voriconazole and itraconazole, whereas Antibiotic Medium 3 with 2% glucose was used for amphotericin B. Minimum fungicidal concentrations (MFCs) were also determined. Amphotericin B was active against all three dimorphic fungi, with MICs at which 90% of the isolates tested are inhibited (MIC90s) of 0.5 to 1 μg/ml. Itraconazole had MIC90s of 0.06 μg/ml for H. capsulatum, 0.125 μg/ml for B. dermatitidis, and 1 μg/ml for C. immitis. The MIC90s of voriconazole were 0.25 μg/ml for all three fungi. Amphotericin B was fungicidal for B. dermatitidis and H. capsulatum with MFCs at which 90% of strains tested are killed (MFC90s) of 0.5 and 2 μg/ml, respectively. It was less active against C. immitis, with MFCs ranging from 0.5 to >16 μg/ml. Voriconazole and itraconazole were lethal for most isolates of B. dermatitidis, with MFC50s and MFC90s of 0.125 and 4 μg/ml, respectively. Both azoles were fungicidal for some isolates of H. capsulatum, with MFC50s of 2 and 8 μg/ml for itraconazole and voriconazole, respectively; neither had a lethal effect upon C. immitis. Our results suggest that voriconazole possesses promising activity against these important human pathogens.

scholarly journals Antifungal Activity of Flocculosin, a Novel Glycolipid Isolated from Pseudozyma flocculosa

2005 ◽  
Vol 49 (4) ◽  
pp. 1597-1599 ◽  
Author(s):  
Benjamin Mimee ◽  
Caroline Labbé ◽  
René Pelletier ◽  
Richard R. Bélanger
Keyword(s):  
Antifungal Activity ◽  
Amphotericin B ◽  
Cell Lines ◽  
Human Cell ◽  
Synergistic Activity ◽  
Human Cell Lines ◽  
Antifungal Properties ◽  
Pseudozyma Flocculosa ◽  
In Vitro Antifungal Activity

ABSTRACT Flocculosin, a glycolipid isolated from the yeast-like fungus Pseudozyma flocculosa, was investigated for in vitro antifungal activity. The compound displayed antifungal properties against several pathogenic yeasts. Synergistic activity was observed between flocculosin and amphotericin B, and no significant cytotoxicity was demonstrated when tested against human cell lines.

Amphotericin B in Lipid Emulsion: Stability, Compatibility, and In Vitro Antifungal Activity

1998 ◽  
Vol 42 (4) ◽  
pp. 762-766 ◽  
Author(s):  
Scott Walker ◽  
Sandra A. N. Tailor ◽  
Mark Lee ◽  
Lisa Louie ◽  
Marie Louie ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Amphotericin B ◽  
Clinical Laboratory ◽  
National Committee ◽  
Compatibility Study ◽  
The Stability ◽  
Few Data ◽  
Reference Strains ◽  
In Vitro Antifungal Activity

ABSTRACT Newer formulations of amphotericin B (AmB) complexed with liposomes or lipid suspensions have been developed. Preliminary studies have suggested that AmB in Intralipid (IL) may be as effective as, but less toxic than, conventional formulations of AmB, but few data are available regarding its stability, compatibility, or in vitro antifungal activity. A compatibility study was done to evaluate the effects of AmB concentrations in IL containing either 10 or 20% soybean oil. The effects of temperature, shaking, and AmB and IL concentrations on the stability of AmB-IL suspensions were analyzed by visual inspection and liquid chromatography. The in vitro antifungal activity of AmB-IL, compared to that of AmB alone against reference strains of Candida species was determined by using a broth macrodilution method in accordance with National Committee for Clinical Laboratory Standards guidelines (M27-T). Samples of AmB-IL which were lightly shaken retained more than 90% of the AmB concentration over 21 days when stored at either 4 or 23°C. Varying the AmB concentration did not appear to affect the stability of AmB-IL. However, a precipitate was formed when mixtures with more than 30% lipid as a proportion of the total volume were centrifuged. AmB-IL and AmB alone had similar in vitro antifungal activities against reference strains of yeasts. Further pharmacologic and clinical studies with AmB-IL are warranted, although AmB should not be combined with IL in concentrations capable of producing a precipitate.

scholarly journals MICs and minimum fungicidal concentrations of amphotericin B, itraconazole, posaconazole and terbinafine in Sporothrix schenckii

2009 ◽  
Vol 58 (12) ◽  
pp. 1607-1610 ◽  
Author(s):  
Carolina Pereira Silveira ◽  
Josep M. Torres-Rodríguez ◽  
Eidi Alvarado-Ramírez ◽  
Francisca Murciano-Gonzalo ◽  
Maribel Dolande ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Latin American ◽  
Geometric Mean ◽  
Sporothrix Schenckii ◽  
Mycelial Form ◽  
Appropriate Treatment ◽  
Inappropriate Treatment ◽  
Immunosuppressed Patients ◽  
Identification Of Species

The in vitro susceptibility of 62 isolates of Sporothrix schenckii in its mycelial form, from Latin-American countries (Peru, Venezuela, Brazil and Uruguay) and Spain, to amphotericin B (AB), itraconazole (IZ), posaconazole (PZ) and terbinafine (TB) was determined by measuring the MICs and minimum fungicidal concentrations (MFCs) using a standardized Clinical and Laboratory Standards Institute method. In general, TB was the most active drug, with the lowest geometric mean (GM) MIC and MFC values amongst isolates from the five countries tested. IZ and PZ showed almost the same activity against all strains tested, except for isolates from Uruguay where IZ gave the highest GM MIC (10.68 mg l−1). AB showed the widest MIC range (0.03–16.0 mg l−1); however, this drug was less active against 79 % of isolates (MICs above 1 mg l−1). MFCs were 5 to 20 times higher than the MICs, but the lowest GM MFC and range values were found for TB. IZ and PZ gave the highest GM MFC. MFC may be a better predictor of therapeutic response than MIC, especially in immunosuppressed patients, making the use of IZ and PZ an inappropriate treatment. There were some differences in susceptibility according to the geographical source of the isolates, with the MIC being lower for TB in Venezuelan strains (P=0.066) and the MFC higher for PZ in Peruvian strains (P=0.02). Thus, geographical origin may be important for appropriate treatment, and may relate to the identification of species of the S. schenckii complex.

In-Vitro and In-Vivo Studies on Novel Chitosan-g-Pluronic F-127 Copolymer Based Nanocarrier of Amphotericin B for Improved Antifungal Activity

2014 ◽  
Vol 4 (3) ◽  
pp. 210-216 ◽  
Author(s):  
Vivek Kumar ◽  
Pramod K. Gupta ◽  
Vivek K. Pawar ◽  
Ashwni Verma ◽  
Renuka Khatik ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Amphotericin B

scholarly journals Amphotericin B-conjugated polypeptide hydrogels as a novel innovative strategy for fungal infections

2018 ◽  
Vol 5 (3) ◽  
pp. 171814 ◽  
Author(s):  
Chang Shu ◽  
Tengfei Li ◽  
Wen Yang ◽  
Duo Li ◽  
Shunli Ji ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Antifungal Activity ◽  
Amphotericin B ◽  
Fungal Infections ◽  
Antifungal Drugs ◽  
Water Soluble ◽  
Naphthalene Acetic Acid ◽  
Innovative Strategy ◽  
Molecular Arrangement

The present work is focused on the design and development of novel amphotericin B (AmB)-conjugated biocompatible and biodegradable polypeptide hydrogels to improve the antifungal activity. Using three kinds of promoting self-assembly groups (2-naphthalene acetic acid (Nap), naproxen (Npx) and dexamethasone (Dex)) and polypeptide sequence (Phe-Phe-Asp-Lys-Tyr, FFDKY), we successfully synthesized the Nap-FFDK(AmB)Y gels, Npx-FFDK(AmB)Y gels and Dex-FFDK(AmB)Y gels. The AmB-conjugated hydrogelators are highly soluble in different aqueous solutions. The cryo-transmission electron microscopy and scanning electron microscopy micrographs of hydrogels afford nanofibres with a width of 20–50 nm. Powder X-ray diffraction analyses demonstrate that the crystalline structures of the AmB and Dex are changed into amorphous structures after the formation of hydrogels. Circular dichroism spectra of the solution of blank carriers and the corresponding drug deliveries further help elucidate the molecular arrangement in gel phase, indicating the existence of turn features. The in vitro drug releases suggest that the AmB-conjugated hydrogels are suitable as drug-controlled release vehicles for hydrophobic drugs. The antifungal effect of AmB-conjugated hydrogels significantly exhibits the antifungal activity against Candida albicans . The results of the present study indicated that the AmB-conjugated hydrogels are suitable carriers for poorly water soluble drugs and for enhancement of therapeutic efficacy of antifungal drugs.

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