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1.
Several dematiaceous fungi frequently isolated from nature are involved in cases of superficial lesions to lethal cerebral infections. Antifungal susceptibility data on environmental and clinical isolates are still sparse despite the advances in testing methods. The objective of this study was to examine the activities of 5-flucytosine, amphotericin B, itraconazole, voriconazole and terbinafine against environmental isolates of Exophiala strains by minimum inhibition concentration (MIC) determination. The strains were obtained from hydrocarbon-contaminated soil, ant cuticle and fungal pellets from the infrabuccal pocket of attine gynes. Broth microdilution assay using M38-A2 reference methodology for the five antifungal drugs and DNA sequencing for fungal identification were applied. Terbinafine was the most active drug against the tested strains. It was observed that amphotericin B was less effective, notably against Exophiala spinifera, also studied. High MICs of 5-flucytosine against Exophiala dermatitidis occurred. This finding highlights the relevance of studies on the antifungal resistance of these potential opportunistic species. Our results also contribute to a future improvement of the standard methods to access the drug efficacy currently applied to black fungi.  相似文献   

2.
Lasiodiplodia theobromae is a rare ocular pathogen. We report a patient with fungal keratitis caused by L. theobromae. The patient was a 75-year-old male, a farmer with diabetes type II, and no previous history of ocular trauma. Histopathology analysis revealed the presence fungi invading Descemet’s membrane of the cornea. The fungus was characterized by septate, highly bulged fungal filaments involving full corneal thickness in the corresponding histopathology specimens. A dematiaceous mold was isolated and initally identified as L. theobromae by microscopic and macroscopic morphology, and further confirmed by PCR-based determination of internal transcribed spacer (ITS) regions of ribosomal DNA. Antifungal susceptibility tests showed sensitivity to amphotericin B (AMB) and voriconazole ( VRC), and resistance to other azoles, including itraconazole (ITC) and fluconazole (FLC). Corneal transplant was performed. Despite in vitro itraconazole resistance, the patient was successfully treated with oral itraconazole, topical voriconazole and natamycin, combined with ocular injections of amphotericin B and voriconazole.  相似文献   

3.
The prognosis of invasive fungal infections (IFI) depends on the speed of diagnosis and treatment. Conventional diagnostic methods are of low sensitivity, laborious and too slow, leading to the need for new, faster, and more efficient diagnostic strategies.There are several techniques for diagnosing a candidemia that are faster than the conventional blood culture (BC). Once yeast growth in BC is detected, species identification can be speeded up by mass spectrometry (30 minutes), commercialised molecular techniques (60-80 minutes) or fluorescent in situ hybridization (90 minutes). The combined detection of biomarkers (antimicellium, mannan and anti-mannan or β-glucan) has shown to be of greater use than their individual use. Commercialised nucleic acid amplification techniques (Septifast®, T2Candida®) are very reliable alternatives to BC. The detection of the capsular antigen of Cryptococcus, by means of latex agglutination or immuno-chromatography, is a valuable technique for cryptococcosis diagnosis.Direct microscopic examination and culture of representative specimens is used for the conventional diagnosis of IFI by filamentous fungi. Detection of galactomannan and β-glucan are considered diagnostic criteria for probable invasive aspergillosis and probable IFI, respectively, despite the lack of specificity of the latter. The detection of fungal volatile organic compounds in breath is an interesting diagnostic strategy in pulmonary infections. Although widely used, nucleic acid detection techniques are not considered diagnostic criteria for IFIs caused by moulds in consensus documents, due to their lack of standardisation. However, they are the only alternative to culture methods in invasive infections by Scedosporium/Lomentospora, Fusarium, zygomycetes, or dematiaceous fungi.  相似文献   

4.
Invasive fungal infections have become a major cause of morbimortality in intensive care patients, persons suffering from cancer or immune deficiencies, and other diseases with impaired immunity. Candida albicans remains the most frequent fungal pathogen, but advances in the diagnosis, prevention and treatment of invasive candidiasis are leading to important etiological changes. Among the emerging invasive mycoses, are those caused by filamentous fungi, such as Aspergillus, Lomentospora/Scedosporium, Fusarium or the Mucorales. Invasive aspergillosis is difficult to diagnose, and although there are diagnostic tools available, their use is not widespread, and their effectiveness vary depending on the group of patients. Clinical suspicion in high-risk patients, radiological diagnosis and the use of biomarkers, such as 1,3-β-D-glucan and galactomannan, can be of great help. However, diagnostic resources are limited in other mycoses, but radiology, pathological studies and the microbiological diagnosis can be useful. The high mortality of these mycoses requires early empirical antifungal treatment in many cases. Voriconazole is the first choice for treatment of the majority of aspergillosis, scedosporiasis, fusariosis and other hyalohyphomycoses. The treatment of mucormycoses, Lomentospora prolificans infections or mycoses by dematiaceous fungi are more complicated. Amphotericin B is active against many mucoralean fungi, but the combination of two or more antifungal agents could be a therapeutic alternative in many amphotericin B-refractory mycoses. Current clinical challenges include improving the diagnosis and the treatment of these mycoses, along with improving the adequate prevention in patients at high risk of suffering from them.  相似文献   

5.
Invasive mould infections are a major cause of morbidity and mortality in hematopoietic stem cell transplant recipients (HSCT). Allogeneic HSCT recipients are at substantially higher risk than autologous HSCT recipients. Although neutropenia following the conditioning regimen remains an important risk factor for opportunistic fungal infections, most cases of invasive mould infection in allogeneic HSCT recipients occur after neutrophil recovery in the setting of potent immunosuppressive therapy for graft-versus-host disease. Invasive aspergillosis is the most common mould infection. However, there has been an increased incidence of less common non-Aspergillus moulds that include zygomycetes, Fusarium sp., and Scedosporium sp. Reflecting a key need, important advances have been made in the antifungal armamentarium. Voriconazole has become a new standard of care as primary therapy for invasive aspergillosis based on superiority over amphotericin B. There is significant interest in combination therapy for invasive aspergillosis pairing voriconazole or an amphotericin B formulation with an echinocandin. There have also been advances in novel diagnostic methods that facilitate early detection of invasive fungal infections that include galactomannan and beta-glucan antigen detection and PCR using fungal specific primers. We review the epidemiology, diagnosis, and management of invasive mould infection in HSCT, with a focus on allogeneic recipients. We also discuss options for prevention and early treatment of invasive mould infections.  相似文献   

6.
Voriconazole (Vfend™) is a new triazole that currently is undergoing phase III clinical trials. This review summarizes the published data obtained by NCCLS methods on the in vitro antifungal activity of voriconazole in comparison to itraconazole, amphotericin B, fluconazole, ketoconazole and flucytosine. Voriconazole had fungistatic activity against most yeasts and yeastlike species (minimum inhibitory concentrations [MICs] <2 μg/ml) that was similar or superior to those of fluconazole, amphotericin B, and itraconazole. Against Candida glabrata and C. krusei, voriconazole MIC ranges were 0.03 to 8 and 0.01 to >4 μg/ml, respectively. For four of the six Aspergillus spp. evaluated, voriconazole MICs (< 0.03 to 2 μg/ml) were lower than amphotericin B (0.25 to 4 μg/ml) and similar to itraconazole MICs. Voriconazole fungistatic activity against Fusarium spp. has been variable. Against F. oxysporum and solani, most studies showed MICs ranging from 0.25 to 8 μg/ml. Voriconazole had excellent fungistatic activity against five of the six species of dimorphic fungi evaluated (MIC90s < 1.0 μg/ml). The exception was Sporothrix schenckii (MIC90s and geometric mean MICs ≥ 8 μg/ml). Only amphotericin B had good fungistatic activity against the Zygomycetes species (voriconazole MICs ranged from 2 to >32 μg/ml). Voriconazole showed excellent in vitro activity (MICs < 0.03 to 1.0 μg/ml) against most of the 50 species of dematiaceous fungi tested, but the activity of all the agents was poor against most isolates of Scedosporium prolificans and Phaeoacremonium parasiticum (Phialophora parasitica). Voriconazole had fungicidal activity against most Aspergillus spp., B. dermatitidis, and some dematiaceous fungi. In vitro/in vivo correlations should aid in the interpretation of these results. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

7.
Fusarium species have emerged as responsible for a broad spectrum of infections, including superficial, locally invasive and disseminated ones, especially in the hospital environment. Since there are few reports of invasive and disseminated fusariosis in children, the aim of this study was to report four cases of nosocomial infection caused by this microorganism in children with cancer hospitalized in a public children’s hospital located in Brazil. Two of these patients were female and two were male. All patients presented febrile neutropenia, while three patients had acute lymphocytic leukemia and one patient had Wilms’ tumor as underlying disease. In two cases, fungi were isolated from blood and identified as Fusarium oxysporum species complex after phenotypic and genotypic studies, while in two other cases fungi were isolated from skin biopsies and identified as Fusarium solani species complex. One patient died 12 days after the onset of cutaneous lesions. All isolates, after susceptibility testing, presented high levels of minimum inhibitory concentration for itraconazole, voriconazole and amphotericin B. Considering the emergence of filamentous fungi as etiologic agents of nosocomial infections, health professionals should be aware of the problems these infections, especially fungal ones, may cause to debilitated patients.  相似文献   

8.
The echinocandins anidulafungin and micafungin and the triazole posaconazole are currently undergoing phase III clinical trials. Caspofungin and voriconazole have recently been licensed for the treatment of aspergillosis (both agents), other less common mould (voriconazole) and candidal (caspofungin) infections. This review summarizes the published in vitro data obtained by NCCLS or NCCLS modified methods on the in vitro fungistatic and fungicidal activities of these five agents for yeasts and moulds in comparison to the established agents, amphotericin B, fluconazole, itraconazole, and flucytosine. Among the yeasts, the echinocandins have less activity for Candida parapsilosis and Candida guilliermondii, no activity for Cryptococcus neoformans and Trichosporon spp., but good fungistatic and fungicidal activity in vivo and in vitro for most of the other Candida spp.; this fungicidal activity has been reported by minimum fungicidal concentrations (MFCs) or time kill curve results. The new triazoles exhibit good fungistatic activity (but not fungicidal) for most Candida spp., C. neoformans, and Trichosporon spp. For the Aspergillus spp. evaluated, the echinocandins have similar or better fungistatic activity than those of amphotericin B and the triazoles, but fungicidal activity has been demonstrated only with amphotericin B and the triazoles, with the exception of fluconazole. Most studies showed posaconazole and voriconazole minimum inhibitory concentrations (MICs) ranging from 0.25 to 8 microg/ml for non-solani Fusarium spp., while MIC and minimum effective concentration (MEC) endpoints of the echinocandins were >8 microg/ml. The fungistatic activity of the triazoles is also superior to that of the echinocandins for most of the dimorphic fungi and the Zygomycetes. However, micafungin has activity for the mould phase of most dimorphic fungi, but not for the parasitic or yeast phase of Paracoccidioides brasiliensis. The echinocandins appear to have variable and species dependent fungistatic activity for the dematiaceous fungi, but all agents have poor or no activity against most isolates of Scedosporium prolificans. Only amphotericin B exhibit good fungistatic activity against the Zygomycetes. The combination of caspofungin with some triazoles, amphotericin B or liposomal amphotericin B has been synergistic in vitro, in animal models and in patients. Breakpoints are not available for any mould and antifungal agent combination. In vitro/in vivo correlations should aid in the interpretation of these results, but standard testing conditions are needed for the echinocandins, especially for mould testing, to obtain reliable results.  相似文献   

9.
Liposomal amphotericin B, voriconazole, and caspofungin are currently used for systemic and severe fungal infections. Patients with malignant diseases are treated with granulocyte-colony stimulating factor (G-CSF) for the recovery of granulocytes after chemotherapy or hematopoietic cell (HC) transplantation. Since they have a high incidence of fungal infections, they inevitably receive antifungal drugs for treatment and prophylaxis. Despite their proven less toxicity for various cell types comparatively with amphotericin B and the decrease in the number of leukocytes that has been reported as a possible complication in clinical studies, the effect of liposomal amphotericin B, voriconazole, and caspofungin on HCs has not been clarified. The present study aimed to examine the in vitro and in vivo effect of these three modern antifungals on HCs. Colony-forming unit (CFU) assays of murine bone marrow cells were performed in methylcellulose medium with or without cytokines and in the presence or absence of various concentrations of liposomal amphotericin B, voriconazole, and caspofungin. In the in vivo experiments, the absolute number of granulocytes was determined during leukocyte recovery in sublethally irradiated mice receiving each antifungal agent separately, with or without G-CSF. In vitro, all three antifungal drugs were nontoxic and, interestingly, they significantly increased the number of CFU-granulocyte-macrophage colonies in the presence of cytokines, at all concentrations tested. This was contrary to the concentration-dependent toxicity and the significant decrease caused by conventional amphotericin B. In vivo, the number of granulocytes was significantly higher with caspofungin plus G-CSF treatment, higher and to a lesser extent higher, but not statistically significantly, with voriconazole plus G-CSF and liposomal amphotericin B plus G-CSF treatments, respectively, as compared with G-CSF alone. These data indicate a potential synergistic effect of these antifungals with the cytokines, in vitro and in vivo, with subsequent positive effect on hematopoiesis.  相似文献   

10.
Although reference broth microdilution protocol is currently available for filamentous fungi antifungal susceptibility testing (AFST), simpler alternatives as Etest® tend to be favoured in clinical routine, making their validation of utmost importance. In this study, Etest® method using 2 % glucose supplemented Muller–Hinton agar was compared to the Clinical and Laboratory Standards Institute (CLSI) M38-A2 protocol for filamentous fungi AFST. The echinocandins, caspofungin and anidulafungin, the azoles voriconazole and posaconazole, and the polyene amphotericin B were tested against 48 Aspergillus spp., seven Fusarium spp., one Beauveria bassiana and three Paecilomyces lilacinus isolates. The majority of the isolates were susceptible to the antifungals tested, and the overall level of agreement between the CLSI and Etest methods was 71.9 % for one dilution and 99.7 % when using two dilutions. Since interpretative breakpoints for filamentous fungi employing the CLSI or Etest methods are not available yet, the established epidemiological cut-off values for Aspergillus spp. were used to distinguish wild-type isolates from those with acquired resistance mechanisms. Forty-five Aspergillus strains did not evidence resistance mutations.  相似文献   

11.
The incidence of opportunistic fungal infections has increased in recent decades due to the growing proportion of immunocompromised patients in our society. Candida krusei has been described as a causative agent of disseminated fungal infections in susceptible patients. Although its prevalence remains low among yeast infections (2–5%), its intrinsic resistance to fluconazole makes this yeast important from epidemiologic aspects. Non mammalian organisms are feasible models to study fungal virulence and drug efficacy. In this work we have used the lepidopteran Galleria mellonella and the nematode Caenorhabditis elegans as models to assess antifungal efficacy during infection by C. krusei. This yeast killed G. mellonella at 25, 30 and 37°C and reduced haemocytic density. Infected larvae melanized in a dose-dependent manner. Fluconazole did not protect against C. krusei infection, in contrast to amphotericin B, voriconazole or caspofungin. However, the doses of these antifungals required to obtain larvae protection were always higher during C. krusei infection than during C. albicans infection. Similar results were found in the model host C. elegans. Our work demonstrates that non mammalian models are useful tools to investigate in vivo antifungal efficacy and virulence of C. krusei.  相似文献   

12.
Neoscytalidium dimidiatum is an opportunistic fungus causing cutaneous infections mostly, which are difficult to treat due to antifungal resistance. In Malaysia, N. dimidiatum is associated with skin and nail infections, especially in the elderly. These infections may be mistaken for dermatophyte infections due to similar clinical appearance. In this study, Neoscytalidium isolates from cutaneous specimens, identified using morphological and molecular methods (28 Neoscytalidium dimidiatum and 1 Neoscytalidium sp.), were evaluated for susceptibility towards antifungal agents using the CLSI broth microdilution (M38-A2) and Etest methods. Amphotericin B, voriconazole, miconazole and clotrimazole showed high in vitro activity against all isolates with MIC ranging from 0.0313 to 1 µg/mL. Susceptibility towards fluconazole and itraconazole was noted in up to 10% of isolates, while ketoconazole was inactive against all isolates. Clinical breakpoints for antifungal drugs are not yet available for most filamentous fungi, including Neoscytalidium species. However, the results indicate that clinical isolates of N. dimidiatum in Malaysia were sensitive towards miconazole, clotrimazole, voriconazole and amphotericin B, in vitro.  相似文献   

13.
The fungal kingdom is extremely diverse – comprised of over 1.5 million species including yeasts, molds and mushrooms. Essentially, all fungi have cell walls that contain chitin and the cells of most fungi grow as tube-like filaments called hyphae. These filamentous fungi, such as the mold Neurospora crassa, develop branched radial networks of hyphae referred to as mycelium. In contrast, non-filamentous fungi do not form radial mycelia, but grow as single cells, which reproduce by either budding or fission such as Saccharomyces cerevisiae or Schizosaccharomyces pombe, respectively. Finally, there are fungi that are capable of switching between single cell, yeast form growth and filamentous growth such as Candida albicans. The switch from yeast to filamentous growth in these so-called dimorphic fungi is a virulence trait in many human and plant pathogens. Highly conserved master regulators of all three fungal growth modes – filamentous, non-filamentous and dimorphic – are the Ras and Rho small GTPases, which spatially and temporally control cell polarity establishment and maintenance. This review summarizes the key roles of the Ras and Rho GTPases during hyphal morphogenesis in a range of fungi.  相似文献   

14.
Fungal osteoarticular infections, including prosthetic joint infections and osteomyelitis, are rare yet present a therapeutic challenge with no guidelines to direct optimal treatment. When these infections occur, the majority are due to Candida species. In addition to systemic therapy, adjunctive antifungal-loaded bone cement has been utilized to successfully treat these infections. Amphotericin B is used most commonly, but cases utilizing voriconazole, fluconazole, and itraconazole have been reported as well. In vitro data suggest better elution of voriconazole from bone cement while there is minimal elution of amphotericin B. Unfortunately, a lack of consistency in the methods of both in vitro studies and case reports makes it difficult to determine if the addition of an antifungal agent in bone cement improves outcomes in fungal osteoarticular infections. This article provides an overview of bone cement as a delivery system for antifungal agents in vitro and in clinical reports.  相似文献   

15.
Certain non-steroidal anti-inflammatory drugs can inhibit fungal growth, fungal prostaglandin E2 production, and enzyme activation. This study aims to investigate the antifungal effect of nimesulide against pathogenic filamentous fungi and yeast. The experiments detailed below were also designed to investigate whether the action is dependent on E2 fungal prostaglandins. Our data showed that nimesulide exhibited potent antifungal activity, mainly against Trichophyton mentagrophytes (ATCC 9533) and Cryptococcus neoformans with MIC values of 2 and 62 μg/mL, respectively. This drug was also able to inhibit the growth of clinic isolates of filamentous fungi, such as Aspergillus fumigatus, and dermatophytes, such as T. rubrum, T. mentagrophytes, Epidermophyton floccosum, Microsporum canis, and M. gypseum, with MIC values ranging from 112 to 770 μg/mL. Our data also showed that the inhibition of fungal growth by nimesulide was mediated by a mechanism dependent on PGE2, which led to the inhibition of essential fungal enzymes. Thus, we concluded that nimesulide exerts a fungicidal effect against pathogenic filamentous fungi and yeast, involving the inhibition of fungal prostaglandins and fungal enzymes important to the fungal growth and colonization.  相似文献   

16.
Melanin is made by several important pathogenic fungi and is implicated in the pathogenesis of a number of mycoses. This study investigates whether the thermally dimorphic fungal pathogen Blastomyces dermatitidis produces melanin. Using techniques developed to study melanization in other fungi, we demonstrate that B. dermatitidis conidia and yeast produce melanin in vitro and that yeast cells synthesize melanin or melanin-like pigment in vivo. Melanization reduced susceptibility to amphotericin B, but not to itraconazole or voriconazole. Since melanin is an important virulence factor in other pathogenic fungi, this pigment may affect the pathogenesis of blastomycosis.  相似文献   

17.
Rational position of voriconazole in the treatment of oncologic inpatients was shown and the criteria of its use in the algorithms of the therapy and prophylaxis of nosocomial fungal infections were developed. The clinical trial enrolled 50 patients with oncologic pathologies. The patients were divided into two groups of possible invasive candidiasis risk. The patients of one group were treated with fluconazole (Diflucan) and those of the other group were treated with voriconazole (Vifend). The spectrum of the hospital fungal flora was determined and susceptibility of 310 clinically important opportunistic fungi was investigated. All the isolates of Candida albicans and C.tropicalis were susceptible to amphotericin B, fluconazole and voriconazole and 79 and 50% of the isolates were susceptible to intraconazole respectively. As for the C.krusei isolates, 67% was susceptible to amphotericin B, 50% was susceptible to fluconazole, 100% was susceptible to voriconazole and none of the strains was susceptible to intraconazole. By the clinical efficacy voriconazole was superior to fluconazole and comparable with amphotericin B, while superior to it by the number of the side effects and by the cost of the treatment course. It was concluded that voriconazole should be considered as the main agent in the antifungal therapy of oncologic patients.  相似文献   

18.
The search for new antimicrobial compounds and the optimization of production methods turn the use of antimicrobial susceptibility tests a routine. The most frequently used methods are based on agar diffusion assays or on dilution in agar or broth. For filamentous fungi, the most common antimicrobial activity detection methods comprise the co-culture of two filamentous fungal strains or the use of fungal extracts to test against single-cell microorganisms. Here we report a rapid, effective and reproducible assay to detect fungal antimicrobial activity against single-cell microorganisms. This method allows an easy way of performing a fast antimicrobial screening of actively growing fungi directly against yeast. Because it makes use of an actively growing mycelium, this bioassay also provides a way for studying the production dynamics of antimicrobial compounds by filamentous fungi. The proposed assay is less time consuming and introduces the innovation of allowing the direct detection of fungal antimicrobial properties against single cell microorganisms without the prior isolation of the active substance(s). This is particularly useful when performing large screenings for fungal antimicrobial activity. With this bioassay, antimicrobial activity of Hypholoma fasciculare against yeast species was observed for the first time.  相似文献   

19.

Background

The incidence of systemic infections by Saccharomyces cerevisiae has increased in recent years, especially among immunocompromised patients. Amphotericin B, voriconazole or echinocandins have been used with favorable outcome against systemic infections by this fungus. However, clinical experience is limited and no in vivo studies have been conducted.

Aims

We evaluated the in vitro activity of nine antifungal compounds against S. cerevisiae and the in vivo efficacy of those three antifungals showing the highest in vitro activity by using a murine model of systemic infection.

Methods

Minimal inhibitory concentrations (MICs) were determined by the microdilution method against three strains of S. cerevisiae. After intravenous infection with 5 × 107 CFUs, animals received liposomal amphotericin B (5 mg/kg), voriconazole (25 mg/kg) or anidulafungin (5 mg/kg). Treatment efficacy was assessed by determining of CFUs/g in liver, kidney, brain, lung and spleen.

Results

5-Fluorocytosine was the most in vitro active compound followed by amphotericin B, voriconazole and anidulafungin. The in vivo study showed that liposomal amphotericin B was the most effective drug driving highest fungal clearance.

Conclusions

All treatments reduced the fungal load in comparison to the control group, being liposomal amphotericin B the most effective drug followed by anidulafungin and finally voriconazole.  相似文献   

20.
Changes in the spectrum of clinically important fungal infection have been observed in recent years. Acremonium species has been responsible for eumycotic mycetomas but has also been increasingly implicated in systemic fungal diseases. A case of Acremonium kiliense fungemia with proven involvement of the lungs in an allogeneic hematopoietic stem cell patient is reported. A high-resolution computed tomography scan of the lungs showed nodules in both lungs. Multiple cultures of blood demonstrated narrow septate hyphae, cylindrical conidia, and solitary tapering phialides and microconidia that remained grouped in slimy heads. The isolate was identified as A. kiliense based on its morphological characteristics and DNA sequence analysis. Susceptibility testing of the clinical isolate was performed to four antifungal agents. Amphotericin B, fluconazole and itraconazole were found to be inactive in vitro against the isolate; however, it was found to be sensitive to voriconazole. This last drug was indicated, and a high-resolution computed tomography scan of the lungs was normal after 10 days. One year later, the patient was free of symptoms and her blood culture was negative for fungi. Thus, voriconazole was effective in treatment for life-threatening A. kiliense infections. In this work, we performed an overview of worldwide clinical infections caused by A. kiliense.  相似文献   

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