SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Fluconazole

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SCY-078 is an orally bioavailable ß-1,3-glucan synthesis inhibitor (GSI) and the first-in-class of structurally novel triterpine antifungals in clinical development for treating candidemia and invasive candidiasis. In vitro susceptibility by broth micro-dilution, antifungal carry-over, and time-kill dynamics were determined for 3 reference (ATCC) strains (C. albicans 90028, C. parapsilosis 90018, and C. tropicalis 750), a Quality Control (QC) strain (C krusei 6258), and 4 other strains (C. albicans MYA-2732, 64124, 76485 and C.glabrata 90030). Caspofungin (CASP), fluconazole (FLC), and voriconazole (VRC) were comparators. For time-kill experiments, SCY-078 and CASP were evaluated at 0.25, 1, 2, 4, 8, and 16x MIC80, and FLU and VORI were evaluated at 4x MIC80 The time to reach 50%, 90%, and 99.9% growth from starting innoculum was determined. Net change in CFU/mL was used to determine EC50, EC90, and Emax SCY-078 MIC range was between 0.0625 - 1 μg/mL and generally similar to CASP. Antifungal carryover was not observed for SCY-078. SCY-078 was fungicidal against 7 isolates at ≥4x MIC (kill ≥3log10) and achieved a 1.7 log10 reduction in CFUs/mL against C. albicans 90028. CASP behaved similarly against each isolate and achieved a 1.5 log10 reduction in CFUs/mL against C. albicans 90028. Reductions of 50% in CFUs/mL were achieved rapidly (1-2.8 h); fungicidal endpoints were reached at 12.1 - 21.8 h at ≥4x MIC. EC90 was reached at ∼5x MIC at each time point to 24 h. EC50 and EC90 were generally similar (8-24 h). Time-kill behavior of CASP was similar to SCY-078. FLC and VRC were fungistatic. Overall, SCY-078 has primarily fungicidal activity against Candida spp. and behaved comparably to CASP.

Concepts: Candida albicans, Antifungals, Candidiasis, Candida, Fungemia, Antifungal drug, Fluconazole, Candida krusei

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The fungal pathogen Cryptococcus neoformans poses a major threat to immunocompromised patients and is a leading killer of human immunodeficiency virus (HIV)-infected patients worldwide. Cryptococci are known to manipulate host macrophages and can either remain latent or proliferate intracellularly within the host phagocyte, a favourable niche that also renders them relatively insensitive to antifungal agents. Here we report an attempt to address this limitation by using a fluorescence-based drug screening method to identify potential inhibitors of intracellular proliferation of C. neoformans. The Prestwick Chemical Library(®) of FDA-approved small molecules was screened for compounds that limit the intracellular replication of a fluorescently-tagged C. neoformans reference strain (H99-GFP) in macrophages. Preliminary screening revealed 19 of 1200 compounds that could significantly reduce intracellular growth of the pathogen. Secondary screening and host cell cytotoxicity assays highlighted fendiline hydrochloride as a potential drug candidate for the development of future anticryptococcal therapies. Live cell imaging demonstrated that this Ca(2+) channel blocker strongly enhanced phagosome maturation in macrophages leading to improved fungal killing and reduced intracellular replication. Whilst the relatively high dose of fendiline hydrochloride required renders it unfit for clinical deployment against cryptococcosis, this study highlights a novel approach for identifying new lead compounds and unravels a pharmacologically promising scaffold towards the development of novel antifungal therapies for this neglected disease.

Concepts: HIV, AIDS, Immune system, Cryptococcus neoformans, Enzyme inhibitor, Flucytosine, Basidiomycota, Fluconazole

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The migrations of different groups to the metal-carbene center of Rh(II) -stabilized iminocarbenes that were derived from N-sulfonyl triazoles are discussed. The reactivity of these Rh-iminocabenes can be tuned easily by variation of substituents in the parent triazole.

Concepts: Fluconazole, Triazole, Triazoles

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Because of the low prevalence of onychomycosis in children, little is known about the efficacy and safety of systemic antifungals in this population. PubMed and Embase databases and the references of related publications were searched in March 2012 for clinical trials (CTs), retrospective analyses (RAs), and case reports (CRs) on the use of systemic antifungals for onychomycosis in children (<18 years). Twenty-six studies (5 CTs, 3 RAs, and 18 CRs) were published between 1976 and 2011. Most of these studies reported the use of systemic terbinafine and itraconazole for the treatment of onychomycosis in children. Therapy with systemic antifungals alone in children age 1 to 17 years resulted in a complete cure rate of 70.8% (n = 151), whereas combined systemic and topical antifungal therapy in one infant and 19 children age 8 and older resulted in a complete cure rate of 80.0% (n = 20). The efficacy and safety profiles of terbinafine, itraconazole, griseofulvin, and fluconazole in children were similar to those previously reported for adults. In conclusion, based on the little information available on onychomycosis in children, systemic antifungal therapies in children are safe and cure rates are similar to the rates achieved in adults.

Concepts: Medicine, Therapy, Antifungals, Antifungal drug, Onychomycosis, Athlete's foot, Fluconazole, Griseofulvin

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The high-affinity reductive iron uptake system that includes a ferroxidase (Cfo1) and an iron permease (Cft1) is critical for the pathogenesis of Cryptococcus neoformans. In addition, a mutant lacking CFO1 or CFT1 not only has reduced iron uptake but also displays a markedly increased susceptibility to azole antifungal drugs. Altered antifungal susceptibility of the mutants was of particular interest because the iron uptake system has been proposed as an alternative target for antifungal treatment. In this study, we used transcriptome analysis to begin exploring the molecular mechanisms of altered antifungal susceptibility in a cfo1 mutant. The wild-type strain and the cfo1 mutant were cultured with or without the azole antifungal drug fluconazole and their transcriptomes were compared following sequencing with Illumina Genome Analyzer IIx (GAIIx) technology. As expected, treatment of both strains with fluconazole caused elevated expression of genes in the ergosterol biosynthetic pathway that includes the target enzyme Erg11. Additionally, genes differentially expressed in the cfo1 mutant were involved in iron uptake and homeostasis, mitochondrial functions and respiration. The cfo1 mutant also displayed phenotypes consistent with these changes including a reduced ratio of NAD(+)/NADH and down-regulation of Fe-S cluster synthesis. Moreover, combination treatment of the wild-type strain with fluconazole and the respiration inhibitor diphenyleneiodonium dramatically increased susceptibility to fluconazole. This result supports the hypothesis that down-regulation of genes required for respiration contributed to the altered fluconazole susceptibility of the cfo1 mutant. Overall, our data suggest that iron uptake and homeostasis play a key role in antifungal susceptibility and could be used as novel targets for combination treatment of cryptococcosis. Indeed, we found that iron chelation in combination with fluconazole treatment synergistically inhibited the growth of C. neoformans.

Concepts: AIDS, Gene, Gene expression, Cryptococcus neoformans, Flucytosine, Antifungal drug, Fluconazole, Cryptococcosis

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An antibacterial is a substance that kills bacteria or slows their growth. An antifungal are the agents that drugs use for treatment of fungal infections. 5- Chloro-1,3-benzoxazol-2(3H)-one (5-Chloro Benzoxazolinone) contains an azole ring structure. Numbers of azole compounds are reported as antibacterial and antifungal agents. Benzoxazolinones naturally occurs in plants. It plays role as defense compounds against bacteria, fungi and insects. Here is synthesis of six Benzoxazolinone derivatives with various substituents. Benzoxazolinone substituted with p-Aminobenzoic acids and sulphanilamide derivatives. The above both substituents are reported as potent antimicrobial agents. Attachment it with azole leads to increase its potency. The other substituents are with 2,4-dichlorobezylchloride. The same rings are found in miconazole and this may lead to increase its antifungal activity. Fluconazole also contains triazole moiety and triazole is having other number of activity like antimicrobial, anti-inflammatory, local anesthetic, antiviral, anticancer, antimalerial etc. Here there is substitution of azole ring at 5-Chloro position in that might increase antibacterial and antifungal activity. Here is the synthesis and interpretation of six final compounds and three intermediates. Synthesis of 5-Chloro Benzoxazolinone derivatives substituted with Halogenated rings, sulphonated and benzylated derivatives and azole derivatives. There was synthesis of P2A, P2B, P4A, P4B, P5A and P6A compounds and their Structures were characterized by UV-Visible, IR, MASS spectroscopy and NMR spectroscopy. The antibacterial activity of all six compounds is measured against various gm+ve and gm-ve bacteria and against fungi.Compound P4A and P4B has good antibacterial and anti fungal activity, half of the Ampicillin and Cephalexin. P4A, P4B, P6A has good activity against S.aureus and E.coli. Compound P2B has good antifungal activity, half of the Miconazole against C.albicans. P2A, P2B, P5A, P6A has almost equal antibacterial activity.

Concepts: Bacteria, Microbiology, Fungus, Meningitis, Antifungals, Antifungal drug, Fluconazole, Itraconazole

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Candida auris is an emerging multidrug-resistant yeast that has been responsible for invasive infections associated with high morbidity and mortality. C. auris strains often demonstrate high fluconazole and amphotericin B minimum inhibitory concentration values, and some strains are resistant to all 3 major antifungal classes. Here we evaluated the susceptibility of 16 C. auris clinical strains, isolated from a wide geographical area, to 10 antifungal agents including APX001A, a novel agent that inhibits the fungal protein Gwt1 (GPI-anchored wall transfer protein 1). APX001A demonstrated significantly lower MIC50 and MIC90 values (0.004 μg/mL and 0.031 μg/mL, respectively) than all other agents tested.The efficacy of the prodrug APX001 was evaluated in an immunocompromised murine model of disseminated C. auris infection. Significant efficacy (80%-100% survival) was observed in all three APX001 treatment groups versus 50% survival for the anidulafungin treatment group. In addition, APX001 showed a significant log reduction in colony forming units (CFU) counts in kidney, lung and brain tissue (1.03 to 1.83) versus the vehicle control. Anidulafungin also showed a significant log reduction in CFU in kidney and lung (1.5 and 1.62, respectively), but did not impact brain CFU. These data support further clinical evaluation of this new antifungal agent.

Concepts: In vitro, Antifungals, Flucytosine, Candidiasis, Ergosterol, Antifungal drug, Fluconazole, Echinocandin

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Molecular epidemiology studies on cryptococcemia are limited. This study aimed to describe the clinical features of patients with bloodstream infections by Cryptococcus sp. in a public tertiary hospital in Mato Grosso do Sul, as well as identify the fungus' molecular type and determine its antifungal susceptibility. Molecular typing was performed using URA5 restriction fragment length polymorphism PCR, and antifungal susceptibility was determined by microdilution method standardized by the Clinical and Laboratory Standards Institute. Over 14 years, 48 patients were diagnosed with cryptococcemia. The majority (72.9 %) was male with a median age of 40 years; 81.3 % of the patients had HIV/AIDS and 72.9 % died. Cryptococcus neoformans was the most commonly isolated species (97.9 %). Molecular analysis identified the genotypes C. neoformans VNI (93.7 %), C. neoformans VNII (4.2 %), and Cryptococcus gattii VGII (2.1 %). In vitro, these fungi were not resistant to fluconazole, itraconazole, voriconazole, and amphotericin B. This is the first description of the molecular types of cryptococcemia agents in central-west Brazil. Its high lethality, especially in HIV-negative patients, suggests that early diagnosis and prompt antifungal therapy are crucial for a good clinical outcome.

Concepts: Fungus, Cryptococcus neoformans, Antifungals, Flucytosine, Basidiomycota, Cryptococcus, Fluconazole, Cryptococcosis

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Antifungal resistance has been associated with biofilm formation in many microorganisms, but not yet in Malassezia pachydermatis. This saprophytic yeast can cause otitis and dermatitis in dogs and has emerged as an important human pathogen, responsible for systemic infections in neonates in intensive care units. This study aims to evaluate the in vitro antifungal susceptibility of M. pachydermatis strains, in both their planktonic and sessile forms, to fluconazole, miconazole, ketoconazole, itraconazole, posaconazole, terbinafine and voriconazole using the XTT assay and Clinical and Laboratory Standards Institute (CLSI) microdilution method. The minimum inhibitory concentration (MIC) values recorded for each drug were significantly higher for sessile cells relative to planktonic cells to the extent that ≥ 90% of M. pachydermatis strains in their sessile form were classified as resistant to all antifungal agents tested. Data suggest that M. pachydermatis biofilm formation is associated with antifungal resistance, paving the way towards investigating drug resistance mechanisms in Malassezia spp.

Concepts: Archaea, Bacteria, Antibiotic resistance, Antifungals, Candidiasis, Antifungal drug, Fluconazole, Ringworm

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Candida species are responsible for many opportunistic fungal infections. Fluconazole is a well-tolerated antifungal drug, commonly used in the treatment of Candidiasis. However, with fluconazole resistance ever increasing, rapid detection and antifungal susceptibility testing of Candida is imperative for proper patient treatment. Presented herein is a cost-effective, simple, and rapid chromogenic agar dilution method for simultaneous Candida species identification and fluconazole susceptibility testing. The results obtained by X-Plate Technology were in absolute concordance with standard microbroth dilution assays. Analysis of 1383 clinical patient samples with suspected vulvovaginal Candidiasis revealed that this technology was able to detect and speciate the Candida isolate and determine the fluconazole susceptibility. The prevalence and susceptibility profiles of the clinical isolates using this method were highly similar to published reports using the microbroth dilution method.

Concepts: Opportunistic infection, Antifungals, Candidiasis, Antifungal drug, Athlete's foot, Fluconazole, Griseofulvin, Ketoconazole