scholarly journals Combined effect of antifungal agents. Fundamental study on amphotericin B and flucytosine.

1985 ◽  
Vol 26 (3) ◽  
pp. 126-132 ◽  
Author(s):  
Hikaru Kume ◽  
Setsuko Murase ◽  
Mayumi Mochizuki
Keyword(s):  
Amphotericin B ◽  
Antifungal Agents ◽  
Combined Effect ◽  
Fundamental Study

Antifúngicos poliénicos. Mecanismo de acción y aplicaciones

2020 ◽  
Vol 63 (2) ◽  
pp. 7-17
Author(s):  
Evelyn Rivera-Toledo ◽  
Alan Uriel Jiménez-Delgadillo ◽  
Patricia Manzano-Gayosso
Keyword(s):  
Antifungal Activity ◽  
Key Words ◽  
Secondary Metabolism ◽  
Amphotericin B ◽  
Antifungal Agents ◽  
Fungal Infections ◽  
Variable Number ◽  
Therapeutic Failure ◽  
Morbidity And Mortality ◽  
Clinical Use

The first compounds with specific antifungal activity were identified in the middle of the last century as a product of the secondary metabolism of bacteria of the order Actinomycetales, and their clinical use significantly diminished the morbidity and mortality associated with severe fungal infections. Many of such biosynthetic compounds are characterized by a chemical polygenic structure, with a variable number of carbon-carbon double bonds. Currently, besides polygenic antimycotics, there are other antifungal agents, such as the azole compounds, that have less toxicity in patients; however, cases of therapeutic failure with such compounds have been documented, therefore, the use of polygenics is still the best alternative in such cases. This review presents data about the properties and applications of antifungal-polygenic compounds using amphotericin B as a model. Key words: Amphotericin B; antifungal polyenes; ergosterol

scholarly journals Sublethal Injury and Resuscitation of Candida albicans after Amphotericin B Treatment

2003 ◽  
Vol 47 (4) ◽  
pp. 1200-1206 ◽  
Author(s):  
Robert S. Liao ◽  
Robert P. Rennie ◽  
James A. Talbot
Keyword(s):  
Cell Death ◽  
Candida Albicans ◽  
Amphotericin B ◽  
Antifungal Agents ◽  
Sybr Green ◽  
Sequential Treatment ◽  
Tetrazolium Salt ◽  
Fungal Cell ◽  
Sublethal Injury

ABSTRACT Amphotericin B treatment was previously shown to inhibit Candida albicans reproduction and reduce the fluorescence of vitality-specific dyes without causing a corresponding increase in the fluorescence of the mortality-specific dyes bis-(1,3-dibutylbarbituric acid)trimethine oxonol and SYBR Green Ι. In the present study, we have confirmed these results and have shown that the numbers of CFU are reduced by 99.9% by treatment with 0.5 μg of amphotericin B per ml for 10 h at 35°C. This reduction was not due to fungal cell death. First, the level of reduction of the tetrazolium salt 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide increased in the presence of concentrations of amphotericin B that caused greater than 90% reductions in the numbers of CFU. Second, fungal cells treated with amphotericin B at a concentration of 0.5 μg/ml were resuscitated by further incubation at 22°C for 15 h in the continued presence of amphotericin B. Third, recovery of the ability to replicate was prevented by sequential treatment with 20 μg of miconazole per ml, which also increased the fluorescence of mortality-specific dyes to near the maximal levels achieved with 0.9 μg of amphotericin B per ml. Sequential treatment with fluconazole and flucytosine did not increase the levels of staining with the mortality-specific dyes. Itraconazole was less effective than ketoconazole, which was less effective than miconazole. The practice of equating the loss of the capacity of C. albicans to form colonies with fungal cell death may give incorrect results in assays with amphotericin B, and the results of assays with caution with other antifungal agents that are lipophilic or that possess significant postantifungal effects may need to be interpreted.

scholarly journals 1148. Activity of Posaconazole and Comparator Antifungal agents Tested Against Filamentous Fungi

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S601-S601
Author(s):  
Mariana Castanheira ◽  
Cecilia G Carvalhaes ◽  
Mary Motyl ◽  
Seongah Han ◽  
Havilland Campbell
Keyword(s):  
Amphotericin B ◽  
Filamentous Fungi ◽  
Antifungal Agents ◽  
Chemical Diversity ◽  
Aspergillus Species ◽  
Asia Pacific ◽  
Broth Microdilution Method ◽  
Center Research ◽  
Scedosporium Species ◽  
Research Grant

Abstract Background Posaconazole (POS) is a broad-spectrum triazole antifungal that exhibits potent antifungal activity against a variety of yeasts and molds. We evaluated the in vitro activities of posaconazole and comparator antifungal agents against 2,554 isolates of filamentous fungi including 2,100 Aspergillus species and 454 non-Aspergillus moulds (98 Fusarium, 81 Mucorales and 76 Scedosporium species isolates) collected worldwide in 2010-2018 from clinically significant infections. Methods Isolates were identified using sequencing and/or MALDI-TOF MS methods. Posaconazole, itraconazole, voriconazole, caspofungin, anidulafungin, micafungin, and amphotericin B were tested using the reference broth microdilution method according to CLSI guidelines. Results Posaconazole showed comparable activity to itraconazole and voriconazole against A. fumigatus. Categorical agreement between posaconazole and the other azoles tested against A. fumigatus ranged from 98.2-98.7%. Most of the Aspergillus species isolates tested (>90%) were WT to all azoles and echinocandins. Among the isolates of A. fumigatus, the rate of NWT strains varied across the different geographic regions. The frequency of azole NWT strains of A. fumigatus from Europe increased steadily from 2010 to 2018. There was no consistent trend for an increased frequency of NWT strains from other geographic areas. The azoles and echinocandins showed poor activity against Fusarium and Scedosporium species. Posaconazole (MIC50/90, 1/2 mg/L) and amphotericin B (MIC50/90, 1/2 mg/L) were the most active agents against the Mucorales isolates. Conclusion Posaconazole exhibited excellent activity against most species of Aspergillus and was comparable to itraconazole and voriconazole. Most Aspergillus species remain susceptible to triazoles. Although there was no evidence for an increasing frequency of NWT strains among A. fumigatus isolates from North America, Latin America or the Asia-Pacific region, we confirm an increase in the rate of NWT strains to all three triazoles among isolates from Europe. Disclosures Mariana Castanheira, PhD, 1928 Diagnostics (Research Grant or Support)A. Menarini Industrie Farmaceutiche Riunite S.R.L. (Research Grant or Support)Allergan (Research Grant or Support)Allergan (Research Grant or Support)Amplyx Pharmaceuticals (Research Grant or Support)Cidara Therapeutics (Research Grant or Support)Cidara Therapeutics (Research Grant or Support)Cipla Ltd. (Research Grant or Support)Cipla Ltd. (Research Grant or Support)Fox Chase Chemical Diversity Center (Research Grant or Support)GlaxoSmithKline (Research Grant or Support)Melinta Therapeutics, Inc. (Research Grant or Support)Melinta Therapeutics, Inc. (Research Grant or Support)Melinta Therapeutics, Inc. (Research Grant or Support)Merck (Research Grant or Support)Merck (Research Grant or Support)Merck & Co, Inc. (Research Grant or Support)Merck & Co, Inc. (Research Grant or Support)Paratek Pharma, LLC (Research Grant or Support)Pfizer (Research Grant or Support)Qpex Biopharma (Research Grant or Support) Cecilia G. Carvalhaes, MD, PhD, A. Menarini Industrie Farmaceutiche Riunite S.R.L. (Research Grant or Support)Allergan (Research Grant or Support)Cidara Therapeutics (Research Grant or Support)Cipla Ltd. (Research Grant or Support)Fox Chase Chemical Diversity Center (Research Grant or Support)Melinta Therapeutics, Inc. (Research Grant or Support)Merck (Research Grant or Support)Merck (Research Grant or Support)Merck & Co, Inc. (Research Grant or Support)Pfizer (Research Grant or Support) Mary Motyl, PhD, Merck & Co, Inc (Employee, Shareholder) Seongah Han, PhD, Merck & Co, Inc. (Employee) Havilland Campbell, BS, Merck & Co, Inc. (Employee)

Effect of Growth Rate on Resistance ofCandida albicans Biofilms to Antifungal Agents

1998 ◽  
Vol 42 (8) ◽  
pp. 1900-1905 ◽  
Author(s):  
George S. Baillie ◽  
L. Julia Douglas
Keyword(s):  
Growth Rate ◽  
Amphotericin B ◽  
Growth Rates ◽  
Antifungal Agents ◽  
Cell Types ◽  
Planktonic Cells ◽  
High Concentration ◽  
Glucose Limitation ◽  
Daughter Cells ◽  
Cell Counts

ABSTRACT A perfused biofilm fermentor, which allows growth-rate control of adherent microbial populations, was used to assess whether the susceptibility of Candida albicans biofilms to antifungal agents is dependent on growth rate. Biofilms were generated under conditions of glucose limitation and were perfused with drugs at a high concentration (20 times the MIC). Amphotericin B produced a greater reduction in the number of daughter cells in biofilm eluates than ketoconazole, fluconazole, or flucytosine. Similar decreases in daughter cell counts were observed when biofilms growing at three different rates were perfused with amphotericin B. In a separate series of experiments, intact biofilms, resuspended biofilm cells, and newly formed daughter cells were removed from the fermentor and were exposed to a lower concentration of amphotericin B for 1 h. The susceptibility profiles over a range of growth rates were then compared with those obtained for planktonic cells grown at the same rates under glucose limitation in a chemostat. Intact biofilms were resistant to amphotericin B at all growth rates tested, whereas planktonic cells were resistant only at low growth rates (≤0.13 h−1). Cells resuspended from biofilms were less resistant than intact biofilm populations but more resistant than daughter cells; the susceptibilities of both these cell types were largely independent of growth rate. Our findings indicate that the amphotericin B resistance of C. albicans biofilms is not simply due to a low growth rate but depends on some other feature of the biofilm mode of growth.

scholarly journals Distribution and antifungal susceptibility of Candida species in patients with increased risk for fungal infections

2016 ◽  
Vol 62 (1) ◽  
pp. 65-76
Author(s):  
Gordana Mirchevska ◽  
Maja Jurhar Pavlova ◽  
Elena Trajkovska-Dokic ◽  
Zaklina Cekovska ◽  
Gordana Jankoska ◽  
...  
Keyword(s):  
Blood Culture ◽  
Amphotericin B ◽  
Critically Ill Patients ◽  
Candida Species ◽  
Antifungal Agents ◽  
Fungal Infections ◽  
Antifungal Susceptibility ◽  
Clinical Specimens ◽  
Fourth Group ◽  
Increased Risk

Candida species are opportunistic yeasts that can be a serious threat for immunocompromised and critically ill patients, and a cause for increased morbidity and mortality in hospitalized patients. The aim of this study was to determine the frequency and distribution of different Candida species in clinical specimens in patients with increased risk for fungal infections, and to determine the antifungal susceptibility profile of invasive Candida species to antifungal agents. During a two year period, clinical specimens from 120 patients divided into 4 groups were analysed at the Institute of microbiology and parasitology, Faculty of Medicine, Skopje, Republic of Macedonia. Each of these 4 groups consisted of specimens from 30 patients, with primary immune deficiency, critically ill patients treated in the intensive care units (ICU), patients with mucosal candidiasis only, and patients with cystic fibrosis. All specimens were investigated with conventional mycological methods. Identification of Candida species was performed with VITEK-2 system (bioMérieux, France). E-test strips of fluconazole, voriconazole, amphotericin B and caspofungin (AB bioMerieux, France) were used for determination of the antifungal susceptibility profile. In this study, a total of 115 isolates of Candida species were confirmed in different clinical specimens (91 isolates from mucosal surfaces and 24 isolates from blood culture). Colonisation of mucosal membranes of gastrointestinal, respiratory and/or urinary tracts was registered in 56.67% (17/30), 56.67% (17/30), 90% (27/30) and 100% (30/30) of the specimens in the first, second, third and fourth group respectively. In all four groups of patients, the following Candida species were confirmed: C. albicans - 55%, C. glabrata - 17.6%, C. parapsilosis - 7.7%, C. tropicalis - 6.6%, unidentified Candida species - 4.4%, C. dubliniensis - 3.3%, C. kefyr - 2.2%, and one isolate of C. rugosa, C. pelliculosa and C. krusei each. Positive blood culture was registered in 23.33% specimens from the first group, 43.33% in the second group, 23.08% of the third group, and in one specimen of the fourth group. The most frequent isolates from blood culture were C. tropicalis and C. krusei, followed by C. albicans, C. parapsilosis and C. tropicalis, and in the second group C. albicans and C. pelliculosa were equally distributed, followed by C. parapsilosis and C. glabrata. All invasive isolates of Candida species were susceptible to amphotericin B, voriconazole and caspofungin. Resistance to fluconazole was registered in 8.3% (2/24) of all confirmed Candida species. Dose-dependent susceptibility to fluconazole was confirmed in 46% (11/24) of the isolates. Our study confirms high prevalence of colonisation and candidemia with non-albicans Candida species. Resistance to antifungal agents was registered only in two isolates of C. krusei. An epidemiological study is necessary for surveillance of dynamics of candidemia and antifungal susceptibility profile of invasive isolates of Candida species in our patients.

Amphotericin B nasal spray has no effect on nasal polyps

2006 ◽  
Vol 120 (12) ◽  
pp. 1023-1025 ◽  
Author(s):  
A Helbling ◽  
A Baumann ◽  
C Hänni ◽  
M Caversaccio
Keyword(s):  
Effective Treatment ◽  
Amphotericin B ◽  
Chronic Rhinosinusitis ◽  
Nasal Spray ◽  
Nasal Polyps ◽  
Inflammatory Process ◽  
Antifungal Agents ◽  
Open Trial ◽  
Potential Treatment

Nasal polyps and chronic rhinosinusitis are the products of an inflammatory process. Recently, fungal involvement has been thought to stimulate the development of polyps, and administration of antifungal agents was therefore considered a potential treatment. Several studies have been published indicating amphotericin B as an effective treatment for nasal polyps and chronic rhinosinusitis. The aim of our investigation was to evaluate the efficacy of intranasal applied amphotericin B on the growth of nasal polyps in a three-month, prospective, open trial. Our results show that nasal amphotericin B spray is not effective for nasal polyps and may even cause deterioration.

scholarly journals In Vitro Activity of Chlorhexidine Compared with Seven Antifungal Agents against 98 Fusarium Isolates Recovered from Fungal Keratitis Patients

2019 ◽  
Vol 63 (8) ◽  
Author(s):  
Claudy Oliveira dos Santos ◽  
Eva Kolwijck ◽  
Henrich A. van der Lee ◽  
Marlou C. Tehupeiory-Kooreman ◽  
Abdullah M. S. Al-Hatmi ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Antifungal Agents ◽  
Culture Collection ◽  
Fungal Keratitis ◽  
Molecular Techniques ◽  
Temperate Climate ◽  
Eye Drops ◽  
Fungal Culture ◽  
Content Type

ABSTRACT Fungal keratitis is a common but severe eye infection in tropical and subtropical areas of the world. In regions with a temperate climate, the frequency of infection is rising in patients with contact lenses and following trauma. Early and adequate therapy is important to prevent disease progression and loss of vision. The management of Fusarium keratitis is complex, and the optimal treatment is not well defined. We investigated the in vitro activity of chlorhexidine and seven antifungal agents against a well-characterized collection of Fusarium isolates recovered from patients with Fusarium keratitis. The fungus culture collection of the Center of Expertise in Mycology Radboudumc/CWZ was searched for Fusarium isolates that were cultured from cornea scrapings, ocular biopsy specimens, eye swabs, and contact lens fluid containers from patients with suspected keratitis. The Fusarium isolates that were cultured from patients with confirmed keratitis were all identified using conventional and molecular techniques. Antifungal susceptibility testing was performed according to the EUCAST broth microdilution reference method. The antifungal agents tested included amphotericin B, voriconazole, posaconazole, miconazole, natamycin, 5-fluorocytosine, and caspofungin. In addition, the activity of chlorhexidine was determined. The fungal culture collection contained 98 Fusarium isolates of confirmed fungal keratitis cases from 83 Dutch patients and 15 Tanzanian patients. The isolates were collected between 2007 and 2017. Fusarium oxysporum (n = 24, 24.5%) was the most frequently isolated species followed by Fusarium solani sensu stricto (n = 18, 18.4%) and Fusarium petroliphilum (n = 11, 11.2%). Amphotericin B showed the most favorable in vitro inhibition of Fusarium species followed by natamycin, voriconazole, and chlorhexidine, while 5-fluorocytosine, posaconazole, miconazole, and caspofungin showed no relevant inhibiting effect. However, chlorhexidine showed fungicidal activity against 90% of F. oxysporum strains and 100% of the F. solani strains. Our study supports the clinical efficacy of chlorhexidine and therefore warrants its further clinical evaluation for primary therapy of fungal keratitis, particularly in low and middle income countries where fungal keratitis is much more frequent and, currently, antifungal eye drops are often unavailable.

scholarly journals Combination therapy with amphotericin B and fluconazole against invasive candidiasis in neutropenic-mouse and infective-endocarditis rabbit models.

1997 ◽  
Vol 41 (6) ◽  
pp. 1345-1348 ◽  
Author(s):  
H Sanati ◽  
C F Ramos ◽  
A S Bayer ◽  
M A Ghannoum
Keyword(s):  
Infective Endocarditis ◽  
Combination Therapy ◽  
Mouse Model ◽  
Amphotericin B ◽  
Antifungal Agents ◽  
Combined Therapy ◽  
Rabbit Model ◽  
Model Treatment ◽  
The Brain

Although there are an increasing number of new antifungal agents available, the morbidity and mortality due to invasive mycoses remain high. The high rates of polyene toxicities and the development of azole resistance have raised the issue of using antifungal agents of these classes in combination, despite theoretical concerns regarding antagonism between such agents. This study was designed to evaluate the in vivo efficacy of combined therapy with amphotericin B and fluconazole against Candida albicans. Two distinct animal models were used in this study: a neutropenic-mouse model of hematogenously disseminated candidiasis and the infective-endocarditis rabbit model. Treatment efficacy was assessed by determining reductions in mortality as well as decreases in tissue fungal densities. In the neutropenic-mouse model, amphotericin B, as well as combination therapy, significantly prolonged survival compared to untreated controls (P < 10(-5) and P = 0.001, respectively). The fungal densities in the kidneys of neutropenic mice were significantly reduced with either amphotericin B monotherapy or amphotericin B-fluconazole combined therapy compared to those of controls (P < 10(-6)). Fluconazole monotherapy also reduced fungal densities in the kidneys; however, this decrease was not statistically significant (P = 0.17). In contrast, treatment with either fluconazole alone or combined with amphotericin B (but not amphotericin B monotherapy) significantly decreased fungal densities in the brain (P = 0.025). In the rabbit endocarditis model, amphotericin B monotherapy or combined therapy significantly decreased fungal densities in cardiac vegetations (P < 0.01 versus the controls). Although no significant antagonism was seen when fluconazole was given in combination with amphotericin B, combination therapy did not augment the antifungal activity of amphotericin B.

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