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1.
The second cause of death among systemic mycoses, cryptococcosis treatment represents a challenge since that 5‐flucytosine is not currently available in Brazil. Looking for alternatives, this study evaluated antifungal agents, alone and combined, correlating susceptibility to genotypes. Eighty Cryptococcus clinical isolates were genotyped by URA5 gene restriction fragment length polymorphism. Antifungal susceptibility was assessed following CLSI‐M27A3 for amphotericin (AMB), 5‐flucytosine (5FC), fluconazole (FCZ), voriconazole (VRZ), itraconazole (ITZ) and terbinafine (TRB). Drug interaction chequerboard assay evaluated: AMB + 5FC, AMB + FCZ, AMB + TRB and FCZ + TRB. Molecular typing divided isolates into 14 C. deuterogattii (VGII) and C. neoformans isolates were found to belong to genotype VNI (n = 62) and VNII (n = 4). C. neoformans VNII was significantly less susceptible than VNI (P = 0.0407) to AMB; C. deuterogattii was significantly less susceptible than VNI and VNII to VRZ (P < 0.0001). C. deuterogattii was less susceptible than C. neoformans VNI for FCZ (P = 0.0170), ITZ (P < 0.0001) and TRB (P = 0.0090). The combination FCZ + TRB showed 95.16% of synergistic effect against C. neoformans genotype VNI isolates and all combinations showed 100% of synergism against genotype VNII isolates, suggesting the relevance of cryptococcal genotyping as it is widely known that the various genotypes (now species) have significant impact in antifungal susceptibilities and clinical outcome. In difficult‐to‐treat cryptococcosis, terbinafine and different antifungal combinations might be alternatives to 5FC.  相似文献   

2.
The Exophiala genus is responsible for many superficial and invasive infections resulting from black fungi. Identification of Exophiala at the species level is based on morphological observations complemented by molecular tests. The aim of this study was to identify 23 clinical isolates of Exophiala spp. and evaluate the antifungal susceptibility to seven different agents. Molecular identification was based on an analysis of ITS region of rDNA using genomic databases. The micromorphology was evaluated by microculture and scanning electron microscopy. The susceptibility tests were performed using the antifungal agents 5‐fluorocytosine (5‐FC), amphotericin B (AMB), itraconazole (ITC), voriconazole (VRC), posaconazole (PSC), caspofungin (CFG) and terbinafine (TRB). The ITS analysis identified 100% of the following isolates as: E. dermatitidis (8), E. xenobiotica (6), E. bergeri (4), E. oligosperma (3), E. spinifera (1) and E. mesophila (1). The antifungal susceptibility tests showed that the triazoles compounds were in vitro the most active agents against Exophiala. ITS sequencing enabled the accurate identification of the 23 tested isolates. The triazoles, particularly itraconazole and posaconazole, exhibited MIC values lower than AMB, CAS and 5‐FC. Although the guidelines do not indicate AMB for treatment against Exophiala spp., this study showed activity for all of the tested species, except E. mesophila.  相似文献   

3.
Chromoblastomycosis is a chronic mycosis that affects the skin and subcutaneous tissues caused by several genera of dematiaceous fungi. There is not a treatment of choice. Thus, tools that help guide clinical practice are fundamental. In this sense, antifungal activity tests in vitro could be useful. However, trials with chromoblastomycosis agents are scarce. The aim of this study was to evaluate both the in vitro susceptibility of 60 chromoblastomycosis agents to five antifungals and the combination of amphotericin B (AMB) and terbinafine (TRB). TRB, itraconazole (ITZ) and ketoconazole (KTZ) were, in this order, the drugs which showed better activity against the chromoblastomycosis agents. The less active drugs were voriconazole (VRZ) and AMB. The more differentiated group was Exophiala spinifera. Cladophialophora carrionii and Fonsecaea spp. are significantly more susceptible to KTZ than Phialophora verrucosa, whereas C. carrionii is significantly more sensitive to VRZ than P. verrucosa and E. spinifera. Assays in this direction allow the knowledge of the susceptibility of the causative agents which may help the management of patients with this disease. This study includes the largest number of these agents and of genera found in the literature.  相似文献   

4.
The susceptibility profile of 91 Sporothrix schenckii isolates in both growth phases was determined by microdilution test (Antifungal Susceptibility Testing of the European Committee for Antimicrobial Susceptibility Testing; AFST‐EUCAST). Amphotericin B (AMB), itraconazole (ITC), posaconazole, ravuconazole and terbinafine were found active in vitro against both phases but minimum inhibitory concentrations values for mycelial phase were significantly higher. Fluconazole (FLC) and voriconazole (VRC) were inactive in vitro against both phases. The E‐test technique was also performed with 41 representative isolates for AMB, FLC, ITC and VRC. Average agreement rates between yeast phase microdilution results and E‐test results were high for AMB (77.5%) and FLC (87.8%), but low for ITC and VRC with rates of 56.4% and 54.5%, respectively. AFST‐EUCAST is not the most recommended test to perform drug susceptibility testing of S. schenckii in clinical laboratories, and E‐test could be an alternative methodology for this purpose, mainly when the activity in vitro of antifungal agents of AMB and FLC are evaluated.  相似文献   

5.
Candida dubliniensis is a recently described yeast that causes infections in mucosal surfaces as well as sterile body sites. Candida dubliniensis develops resistance to fluconazole (FLC) more rapidly than the closely related species C. albicans. The killing activity of amphotericin B (AMB), 5‐fluorocytosine (5FC), FLC, voriconazole (VRC) and posaconazole (POS) was determined against six C. dubliniensis clinical isolates, identified using molecular biological methods and C. dubliniensis CD36 reference strain. Minimum inhibitory concentrations (MICs) were determined using the Clinical and Laboratory Standards Institute standard procedure. Time‐kill assays were performed using RPMI‐1640 as test media over a 48‐h period. AMB proved to be fungicidal at ≥0.5 μg ml?1 against all clinical isolates after 48 h. 5FC was only fungicidal at 32–64× MIC (4–8 μg ml?1) against all C. dubliniensis isolates. FLC, VRC and POS were fungistatic; decrease in colony number was observed only at the highest concentrations tested (8, 4 and 4 μg ml?1, respectively). Triazoles invariably showed fungistatic effect at concentrations attainable in the serum. In clinical situations when a fungicidal antifungal is desirable, AMB may be used.  相似文献   

6.
Because published reports indicate that the antibiotic colistin (COL) has antifungal properties, this study investigated the antifungal in vitro activity of COL as single agent and in combination with the antifungal compounds voriconazole (VRC), caspofungin (CAS) and amphotericin B (AMB) against Scedosporium/Pseudallescheria spp., Exophiala dermatitidis and Geosmithia argillacea. In total, susceptibility was determined for 77 Scedosporium/Pseudallescheria spp., 82 E. dermatitidis and 17 G. argillacea isolates. The minimal inhibitory concentrations (MICs) of COL and the antifungals as single compound and in combination were determined with MIC test strips. Drug interactions were detected by crossing the MIC test strips at a 90º angle. The fractional inhibitory concentration index was used to categorise the drugs’ interaction. The MIC50 value of COL was 12 μg ml?1 for S. prolificans, 16 μg ml?1 for P. apiosperma, 16 μg ml?1 for P. boydii, 12 μg ml?1 for E. dermatiditis and 6 μg ml?1 for G. argillacea. VRC was the most active drug in combination without any antagonism with the exception of few P. boydii isolates. COL as single agent and in most combinations with antifungals exhibits in vitro antifungal activity against filamentous ascomycetes occurring in cystic fibrosis patients and may offer a novel therapeutic option, especially for multidrug‐resistant S. prolificans.  相似文献   

7.
Typically, the onset of candidiasis is characterised by the appearance of a biofilm of Candida albicans, which is associated with several diseases including oral candidiasis in young and elderly people. The objective of this work was to investigate the in vitro fungicidal activity as well as the antibiofilm activity of ambroxol (AMB) against C. albicans growth. In the present investigation, the fungicidal activity of AMB was established using the cell viability 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay. Also the minimum inhibitory concentration (MIC) of AMB required to inhibit the fungal growth was determined. Simultaneously, the antibiofilm activity of AMB was evaluated using fluorescence microscopy. The study revealed that 2 mg ml?1 of AMB exhibited higher fungicidal activity than 3.3 mg ml?1 of terbinafine, one of most common commercial antifungals. A MIC of 1 mg ml?1 was determined for AMB to interfere with C. albicans growth. Furthermore, AMB was found to be effective in inhibiting the biofilm formation of C. albicans and exerted its fungicidal activity against the fungal cells interspersed in the preformed biofilm. The study suggests a potential role of the mucolytic agent, AMB, as an interesting therapeutic alternative in the treatment of oral candidiasis.  相似文献   

8.
Epidemiological cut‐off values (ECVs) based on minimal inhibitory concentration (MIC) distribution have been recently proposed for some antifungal drug/Cryptococcus neoformans combinations. However, these ECVs vary according to the species studied, being serotypes and the geographical origin of strains, variables to be considered. The aims were to define the wild‐type (WT) population of the C. neoformans species complex (C. neoformans) isolated from patients living in Argentina, and to propose ECVs for six antifungal drugs. A total of 707 unique C. neoformans isolates obtained from HIV patients suffering cryptococcal meningitis were studied. The MIC of amphotericin B, flucytosine, fluconazole, itraconazole, voriconazole and posaconazole was determined according to the EDef 7.2 (EUCAST) reference document. The MIC distribution, MIC50, MIC90 and ECV for each of these drugs were calculated. The highest ECV, which included ≥95% of the WT population modelled, was observed for flucytosine and fluconazole (32 μg ml?1 each). For amphotericin B, itraconazole, voriconazole and posaconazole, the ECVs were: 0.5, 0.5, 0.5 and 0.06 μg ml?1 respectively. The ECVs determined in this study may aid in identifying the C. neoformans strains circulating in Argentina with decreased susceptibility to the antifungal drugs tested.  相似文献   

9.
Candida kefyr is an emerging pathogen able to cause disseminated infection, especially in immunocompromised patients. Although guidelines for the treatment of invasive candidiasis have been published, no specific recommendations against C. kefyr are available. We determine the in vitro killing activity of amphotericin B (AMB), fluconazole (FLC) and caspofungin (CFG) as well as their efficacy in a murine model of systemic infection by two C. kefyr strains. Time‐kill curves of AMB, FLC and CFG were determined in final volumes of 10 ml containing the assayed drugs ranged from 0.03 to 32 μg ml?1 at different time points and efficacy of the drugs was evaluated in a systemic model of candidiasis, conducted in immunosuppressed mice, through survival, (1→3)‐β‐D‐glucan levels in serum and fungal load in kidneys. AMB and CFG showed fungicidal and FLC fungistatic activity against both isolates. The three drugs were able to reduce fungal burden in kidneys and (1→3)‐β‐D‐glucan concentration in serum of infected mice, with CFG showing the highest efficacy, followed by FLC. In conclusion, CFG showed efficacy over AMB and FLC against the systemic candidiasis by C. kefyr. The established epidemiological cut‐off for anidulafungin seems the best indicator of outcome for echinocandins.  相似文献   

10.
FungisomeTM is a liposomal preparation of amphotericin B (AMB), already marketed in India. However, its antifungal activity has not been evaluated against a wide range of fungal pathogens. The study was planned to elucidate the in vitro antifungal activity of FungisomeTM against wide range of fungi and compare it with AMB deoxycholate (AMB‐d), voriconazole (VOR), itraconazole (ITR) and fluconazole (FLU). Minimum inhibitory concentrations (MICs) of the drugs were determined for 262 clinical fungal isolates, including yeast, dimorphic and filamentous fungi, by broth microdilution method approved by Clinical and Laboratory Standards Institute, USA (yeast, M27‐A3; filamentous fungi, M38‐A2). The MIC90s of FungisomeTM were 0.125, 0.5 and 0.25 mg l?1 against yeast, filamentous and dimorphic fungi respectively. In comparison, MIC90s of AMB‐d, FLU, ITR and VOR were 1, 1 and 1 mg l?1 (AMB‐d), 4, 64 and 64 mg l?1 (FLU), 1, 16 and 16 mg l?1 (ITR) and 0.5, 4 and 16 mg l?1 (VOR) against yeast, filamentous and dimorphic fungi respectively. The MIC of FungisomeTM was two to 16‐fold lower than AMB‐d. These results reveal an efficient in vitro activity of FungisomeTM.  相似文献   

11.
Invasive aspergillosis (IA) has become increasingly common and is characterised by high morbidity and mortality. Upcoming resistance threatens treatment with azoles and highlights the continuous need for novel therapeutics. This laboratory study investigated the in vitro and in vivo potential of the alkylphospholipid oleylphosphocholine (OlPC) against Aspergillus. In vitro activities of OlPC, miltefosine, posaconazole and voriconazole were determined for Aspergillus fumigatus, A. niger, A. terreus and A. flavus. In vivo efficacy of OlPC was evaluated in a systemic A. fumigatus mouse model, adopting a short‐term and long‐term oral or intraperitoneal dosing regimen. OlPC showed good in vitro activity against A. fumigatus (IC50 = 1.04 μmol l?1). Intraperitoneal administration of 50 mg kg?1 day?1 OlPC significantly reduced the fungal organ burdens at 4 days post‐infection (dpi). Although 5‐ and 10‐day OlPC treatment improved survival, organ burdens were not affected at 10 and 15 dpi. While this study showed excellent in vitro activity of OlPC against Aspergillus spp., its therapeutic efficacy in an acute mouse model for IA was less convincing. Given the limited therapeutic options in the current antifungal market for invasive infections, OlPC activity should be assessed in a less stringent in vivo model, potentially in combination treatment with other already marketed antifungal drugs.  相似文献   

12.
The aim of this study was to examine the antifungal activity of amphotericin B, caspofungin and posaconazole on Candida albicans biofilms in the intermediate and mature development phases. Candida albicans biofilms, previously grown for either 24, 48 or 72 h in 96‐well microtitre plates, were treated for 48 h with amphotericin B, caspofungin or posaconazole in increasing concentrations according to the respective minimal inhibitory concentration (MIC) determined for planktonic cells (1–128 × MIC). The biofilms were quantified using the mean optical density (OD) determined by XTT assay. Antifungal activities were expressed as percentage of reduction in OD of drug‐treated biofilms compared to untreated biofilms. To test the fungicidal activity of antifungal agents, the unfixed biofilms were scraped off and seeded to Sabouraud agar. Caspofungin and amphotericin B showed higher activity against C. albicans biofilm grown for 24 h and 72 h (≥50% reduction of OD) than biofilms grown for 48 h, whereas posaconazole showed similar, but reduced activity against all phases of C. albicans biofilm (≤50% reduction of OD). Caspofungin at 1–4 × MIC achieved the greatest decrease in the biofilm OD grown for 24, 48 and 72 h, whereas amphotericin B showed dose‐dependent activity. However, all tested antifungals failed to reach fungicidal activity in all biofilm development phases.  相似文献   

13.
The fungi Paecilomyces variotii is a potential pathogen in immunocompromised and immunocompetent patients. Their rare association with clinical disease results in scarce literature regarding susceptibility and treatment. Here, we discuss a case involving successful treatment of probable P. variotii pneumonia with posaconazole after treatment failure with voriconazole. The current literature related to antifungal susceptibility profiles, microbiological identification methods and clinical management of infections caused by this organism is also reviewed.  相似文献   

14.
Central nervous system trichosporonosis is a rare clinical entity and so far only six cases including three each of brain abscess and meningitis has been on record. We report a rare case of chronic meningo‐ventriculitis and intraventricular fungal ball due to Trichosporon asahii in an 18‐year‐old immunocompetent male from Burundi, east Africa. Neuroendoscopy showed multiple nodules and a fungal ball within the ventricle, which on culture grew T. asahii. He was initially empirically treated with liposomal amphotericin B. However, the antifungal susceptibility testing of T. asahii isolate revealed high minimum inhibitory concentration for amphotericin B (2 μg ml?1), flucytosine (16 μg ml?1) and caspofungin (2 μg ml?1) but exhibited potent activity for voriconazole, posaconazole, itraconazole and fluconazole. The patient rapidly succumbed to cardiac arrest before antifungal therapy could be changed. Although disseminated trichosporonosis has been increasingly reported the diagnosis represents a challenge especially in rare clinical settings such as intraventricular fungal ball in the present case, which has not been described previously.  相似文献   

15.
Phaeosphaeriaceae is a family in the order Pleosporales containing numerous plant pathogens, endophytes, lichenised fungi, and environmental saprobes. A novel genus, Tintelnotia is introduced containing two species, one of which caused an eye infection and several nail infections in humans. All species of Tintelnotia produce conidia in soft pycnidia with a wide ostiole. The generic type species is T. opuntiae causing necrotic spots on cactus plants. The isolates of the human opportunist T. destructans showed variable susceptibility pattern to a panel of common antifungal agents. The MICs of amphotericin B, voriconazole, posaconazole and itraconazole were 1 μg/mL, complemented by an in vitro MEC of 16 μg/mL against caspofungin; the MIC of terbinafine was 0.125 μg/mL. The latter compound contributed to the successful therapy in the ocular mycosis refractory to standard antifungal therapy, the benefit of terbinafine should be highlighted as a therapeutic option especially in difficult‐to‐treat fungal keratitis.  相似文献   

16.
Chromoblastomycosis is a chronic granulomatous disease caused frequently by fungi of the Fonsecaea genus. The objective of this study was the phenotypic and molecular identification of F. pedrosoi strains isolated from chromoblastomycosis patients in Mexico and Venezuela. Ten strains were included in this study. For phenotypic identification, we used macroscopic and microscopic morphologies, carbohydrate assimilation test, urea hydrolysis, cixcloheximide tolerance, proteolitic activity and the thermotolerance test. The antifungal activity of five drugs was evaluated against the isolates. Molecular identification was performed by sequencing the internal transcribed spacer (ITS) ribosomal DNA regions of the isolated strains. The physiological analysis and morphological features were variable and the precise identification was not possible. All isolates were susceptible to itraconazole, terbinafine, voriconazole and posaconazole. Amphotericin B was the least effective drug. The alignment of the 559‐nucleotide ITS sequences from our strains compared with sequences of GenBank revealed high homology with F. pedrosoi ( EU285266.1 ). In this study, all patients were from rural areas, six from Mexico and four from Venezuela. Ten isolates were identified by phenotypic and molecular analysis, using ITS sequence and demonstrated that nine isolates from Mexico and Venezuela were 100% homologous and one isolate showed a small genetic distance.  相似文献   

17.
We studied 23 clinical and environmental strains of Sporothrix schenckii sensu lato collected from 1984 to 2017 in Argentina. The molecular identification (partial sequencing of a fragment of the calmodulin gene) of the strains was performed. For the yeast and mycelial phases, the in vitro susceptibility testing by a microdilution reference method was determined against eight antifungal drugs. Strains studied were identified as S. schenckii sensu stricto 13 (56.5%), S. brasiliensis 8 (34.7%) and S. globosa 2 (8.7%). The most active antifungal drugs tested for the yeast and mycelial phases expressed as geometric mean (GM ) value of the minimal inhibitory concentration (MIC ) (μg mL?1) were terbinafine (0.07 and 0.24), posaconazole (0.13 and 0.58), itraconazole (0.38 and 1.10) and ketoconazole (0.22 and 0.89), while fluconazole (110.10 and 131.92) and flucytosine (2.96 and 79.03) were the less active. For voriconazole and amphotericin B the GM ‐MIC values were acceptably low for the yeast phase (0.39 and 0.72 μg mL?1), while the mycelial phase showed values ≥2‐fold higher (8.76 and 1.88 μg mL?1), P  < .05. Here, we described S. schenckii sensu stricto, S. brasiliensis and S. globosa, these species were isolated from humans, animals and soil and are circulating in Argentina since at least 1984.  相似文献   

18.
Molecular typing and antifungal susceptibility testing of 34 clinical Serbian Cryptococcus neoformans isolates from 25 patients was retrospectively performed. Amplified fragment length polymorphism (AFLP) fingerprinting was used for genotyping, whereas a novel real‐time PCR was used to determine the mating‐ and serotype. The antifungals amphotericin B, 5‐fluorocytosine, fluconazole, voriconazole, itraconazole and posaconazole were used to determine the antifungal susceptibility profiles. The majority of isolates belonged to genotype AFLP1/VNI (= 20; 58.8%), followed by AFLP2/VNIV (= 10; 29.4%), AFLP3/VNIII (= 3; 8.8%) and AFLP1B/VNII (= 1; 2.9%). All AFLP1/VNI isolates were mating–serotype αA, the sole AFLP1B/VNII isolate was found to be a A, whereas AFLP2/VNIV harboured serotype D isolates with either the a (= 2; 5.9%) or α (= 8; 23.5%) mating‐type allele. The isolates (= 3; 8.8%) that were found to be genotype AFLP3/VNIII had the hybrid mating‐ and serotype combination a A‐αD. In vitro antifungal susceptibility testing showed that all isolates were susceptible to amphotericin B, voriconazole and posaconazole. Low resistance level was observed for fluconazole (= 1; 2.9%) and 5‐fluorocytosine. (= 2; 5.8%). A large percentage of isolates was found to be susceptible dose dependent to itraconazole (= 16; 47.1%). AFLP1/VNI was the most common genotype among clinical C. neoformans isolates from immunocompromised patients in Serbia. C. neoformans from HIV‐negative patients were significantly less susceptible to 5‐fluorocytosine (P < 0.01). Correlation between genotypes and antifungal susceptibility was not observed.  相似文献   

19.
Cryptococcal meningitis is the most important opportunistic fungal infection with a high mortality in HIV‐patients in less developed regions. Here, we report a case of cryptococcal meningitis in a 49‐year‐old HIV‐positive female due to Cryptococcus neoformans (serotype A, mating‐type alpha, genotype AFLP1/VNI) in Sari, Iran. In vitro antifungal susceptibility tests showed MICs of isavuconazole (0.016 μg ml?1), voriconazole (0.031 μg ml?1), posaconazole (0.031 μg ml?1), itraconazole (0.063 μg ml?1), amphotericin B (0.125 μg ml?1) and fluconazole (8 μg ml?1). Despite immediate antifungal therapy, the patient died 4 days later due to respiratory failure. Cryptococcal infections have been infrequently reported from Iran and therefore we analysed all published cases of cryptococcosis in Iran since the first reported case from 1969.  相似文献   

20.
Despite the common, worldwide, occurrence of dermatophytes, little information is available regarding susceptibility profiles against currently available and novel antifungal agents. A collection of sixty‐eight clinical Trichophyton species and Epidermophyton floccosum were previously identified and verified to the species level by sequencing the internal transcribed spacer (ITS) regions of rDNA. MICs of amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, isavuconazole, terbinafine and MECs of caspofungin and anidulafungin were performed based on CLSI M38‐A2. The resulting MIC90s of all strains were, in increasing order, as follows: terbinafine (0.063 mg l?1); posaconazole (1 mg l?1); isavuconazole and anidulafungin (2 mg l?1); itraconazole, voriconazole, amphotericin B, and caspofungin (4 mg l?1) and fluconazole (>64 mg l?1). These results confirm that terbinafine is an excellent agent for treatment of dermatophytosis due to T. rubrum, T. mentagrophytes, T. verrucosum, T. schoenleinii and E. floccosum. In addition, the new azoles POS and ISA are potentially useful antifungals to treat dermatophytosis. However, the clinical effectiveness of these novel antifungals remains to be determined.  相似文献   

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