SciCombinator

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Concept: Aspergillosis

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Invasive aspergillosis remains a major cause of death among the immunocompromised population and those receiving long-term immunosuppressive therapy. In light of increased azole resistance, variable outcomes with existing echinocandin mono and combination therapy, and persistent high mortality rates, new antifungal agents for the treatment of invasive aspergillosis are clearly needed.SCY-078 is the first in class triterpenoid antifungal, a novel class of glucan synthase inhibitors, with broadin vitroandin vivoactivity against a broad spectrum ofCandidaandAspergillusIn vitrotesting of clinical strains ofAspergillus fumigatusand non-fumigatusstrains showed potent fungistatic activity of SCY-078 (minimum effective concentration, MEC90= 0.125 μg/ml) as compared with amphotericin B (MIC90= 8 μg/ml) and voriconazole (MIC90= 2 μg/ml). Combination testing of SCY-078 with isavuconazole or voriconazole demonstrated synergistic activity against the majority of the azole-susceptible strains tested, and SCY-078 in combination with amphotericin B was synergistic against the azole-susceptible strains, as well as one known resistantcyp51Amutant. SCY-078 may be an important additional antifungal for first-line or salvage mono or combination treatment of invasive aspergillosis.

Concepts: Mortality rate, Opportunistic infection, Aspergillosis, Antifungals, Flucytosine, Candidiasis, Ergosterol, Echinocandin

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F901318 is an antifungal agent with a novel mechanism of action and potent activity against Aspergillus spp. An understanding of the pharmacodynamics (PD) of F901318 is required for selection of effective regimens for study in phase II and III clinical trials. Neutropenic murine and rabbit models of invasive pulmonary aspergillosis were used. The primary PD endpoint was serum galactomannan. The relationships between drug exposure and the impacts of dose fractionation on galactomannan, survival, and histopathology were determined. The results were benchmarked against a clinically relevant exposure of posaconazole. In the murine model, administration of a total daily dose of 24 mg/kg of body weight produced consistently better responses with increasingly fractionated regimens. The ratio of the minimum total plasma concentration/MIC (Cmin/MIC) was the PD index that best linked drug exposure with observed effect. An average Cmin (mg/liter) and Cmin/MIC of 0.3 and 9.1, respectively, resulted in antifungal effects equivalent to the effect of posaconazole at the upper boundary of its expected human exposures. This pattern was confirmed in a rabbit model, where Cmin and Cmin/MIC targets of 0.1 and 3.3, respectively, produced effects previously reported for expected human exposures of isavuconazole. These targets were independent of triazole susceptibility. The pattern of maximal effect evident with these drug exposure targets was also apparent when survival and histopathological clearance were used as study endpoints. F901318 exhibits time-dependent antifungal activity. The PD targets can now be used to select regimens for phase II and III clinical trials.IMPORTANCE Invasive fungal infections are common and often lethal. There are relatively few antifungal agents licensed for clinical use. Antifungal drug toxicity and the emergence of drug resistance make the treatment of these infections very challenging. F901318 is the first in a new class of antifungal agents called the orotomides. This class has a novel mechanism of action that involves the inhibition of the fungal enzyme dihydroorotate dehydrogenase. F901318 is being developed for clinical use. A deep understanding of the relationship between dosages, drug concentrations in the body, and the antifungal effect is fundamental to the identification of the regimens to administer to patients with invasive fungal infections. This study provides the necessary information to ensure that the right dose of F901318 is used the first time. Such an approach considerably reduces the risks in drug development programs and ensures that patients with few therapeutic options can receive potentially life-saving antifungal therapy at the earliest opportunity.

Concepts: Pharmacology, Clinical trial, Aspergillosis, Aspergillus, Antifungals, Antifungal drug, Athlete's foot, Griseofulvin

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The European Conference on Infections in Leukemia (ECIL) provides recommendations for diagnostic strategies and prophylactic, pre-emptive or targeted therapy strategies for various types of infection in patients with hematological malignancies or hematopoietic stem cell transplantation recipients. Meetings are held every two years since 2005 and evidence-based recommendations are elaborated after evaluation of the literature and discussion among specialists of nearly all European countries. In this manuscript, the ECIL group presents the 2015-update of the recommendations for the targeted treatment of invasive candidiasis, aspergillosis and mucormycosis. Current data now allow a very strong recommendation in favor of echinocandins for first line therapy of candidemia irrespective of the underlying predisposing factors. Anidulafungin has been given the same grading as the other echinocandins for hemato-oncological patients. The beneficial role of catheter removal in candidemia is strengthened. Aspergillus guidelines now recommend the use of either voriconazole or isavuconazole for first line treatment of invasive aspergillosis, while first line combination antifungal therapy is not routinely recommended. As only few new data were published since the last ECIL guidelines, no major changes were brought to mucormycosis recommendations.

Concepts: Cancer, Bone marrow, Chemotherapy, Hematology, Hematopoietic stem cell transplantation, Aspergillosis, Antifungals, Candidiasis

28

Voriconazole is a first-line agent for the treatment of invasive pulmonary aspergillosis (IPA). There are increasing reports of Aspergillus fumigatus isolates with reduced susceptibility to voriconazole.

Concepts: In vitro fertilisation, In vitro, Aspergillosis, Aspergillus, Aspergillus fumigatus, Voriconazole

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IgE sensitization to Aspergillus fumigatus and a positive sputum fungal culture result are common in patients with refractory asthma. It is not clear whether these patients would benefit from antifungal treatment.

Concepts: Asthma, Aspergillosis, Aspergillus, Aspergillus fumigatus, Aspergillus oryzae

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Background: Itraconazole (ITZ), a triazole antifungal agent, is a poorly water-soluble drug that is orally administered for treatment of fungal infections such as allergic bronchopulmonary aspergillosis (ABPA) and invasive aspergillosis (IA). ABPA is relatively well controlled but IA can be fatal, especially in immunosuppressed patients. Aerosolized ITZ delivered to the lung may provide a local treatment and prophylaxis against IA at the primary site of infection in the lungs. Variations of the percent fine particle fraction (FPF), the percent emitted dose, and the physical properties of the aerosol (e.g., crystallinity) can confound consistent delivery. Methods: ITZ NanoClusters were formulated via milling (top-down process) or precipitation (bottom-up process) without using any excipients. Itraconazole formulations (ITZ) were prepared by milling 1 gram of micronized itraconazole in 300 mL of fluid. The suspension was collected at 0.5, 1, and 2 hours milling time. Milled ITZ was compared to ITZ prepared by anti-solvent precipitation and to the stock micronized itraconazole. The aerosolization performance of ITZ formulations was determined using an Andersen Cascade Impactor (ACI). Results: The physicochemical properties and aerosol performance of different ITZ NanoClusters suggested an optimized wet milling was the preferred process compared to precipitation. ITZ NanoClusters prepared by wet milling showed better aerosol performance compared to micronized ITZ as received and ITZ NanoClusters prepared by precipitation. ITZ NanoClusters prepared by precipitation methods also showed an amorphous state, while ITZ milled in 10% EtOH maintained the crystalline character of ITZ throughout a 2 hour milling time. Conclusions: The aerosol performance of milled ITZ NanoClusters was dramatically improved compared to micronized ITZ as received due to the difference of drug particle structures. ITZ NanoCluster formulations represent a potential engineered drug particle approach for inhalation therapy, providing effective aerosol properties and stability due to the crystalline state of the drug powders.

Concepts: Crystal, Physical chemistry, Particulate, Aerosol, Aspergillosis, Allergic bronchopulmonary aspergillosis, Amorphous solid, Itraconazole

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Aspergillus fumigatus is a conditional pathogen and the major cause of life threatening invasive aspergillosis (IA) in immunocompromised patients. The early and rapid detection of A. fumigatus infection is still a major challenge. In this study, the new member of fungal annexin family annexin C4 was chosen as the target to design loop-mediated isothermal amplification (LAMP) assays for the rapid, specific, and sensitive detection of A. fumigatus. Evaluation on the specificity of the LAMP developed showed that no false-positive results were observed for the 22 non-A. fumigatus strains including five species of Aspergillus genus. Its detection limit was approximately 10 copies per reaction in reference plasmids, with higher sensitivity than that of real-time quantitative PCR (qPCR) at 10(2) copies for the same target. A total of 69 clinical patients comprised of probable IA (n = 14) and possible IA infection patients (n = 55) were subjected to the LAMP assay developed, and 14 probable IA patients (100%) and 34 possible IA patients (61.82%) were detected positive. When the detection using the LAMP developed was compared with that using qPCR in 69 clinical samples, LAMP demonstrated a sensitivity of 89.19% and the concordant rate of two methods was up to 72.46%. Accordingly, a valuable LAMP assay for rapid, specific, and simple detection of A. fumigatus in clinical testing has been developed.

Concepts: Polymerase chain reaction, Type I and type II errors, Sensitivity and specificity, Real-time polymerase chain reaction, Laboratory techniques, Aspergillosis, Aspergillus, Aspergillus fumigatus

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We describe a novel heterothallic species in Aspergillus section Fumigati, namely A. felis (neosartorya-morph) isolated from three host species with invasive aspergillosis including a human patient with chronic invasive pulmonary aspergillosis, domestic cats with invasive fungal rhinosinusitis and a dog with disseminated invasive aspergillosis. Disease in all host species was often refractory to aggressive antifungal therapeutic regimens. Four other human isolates previously reported as A. viridinutans were identified as A. felis on comparative sequence analysis of the partial β-tubulin and/or calmodulin genes. A. felis is a heterothallic mold with a fully functioning reproductive cycle, as confirmed by mating-type analysis, induction of teleomorphs within 7 to 10 days in vitro and ascospore germination. Phenotypic analyses show that A. felis can be distinguished from the related species A. viridinutans by its ability to grow at 45°C and from A. fumigatus by its inability to grow at 50°C. Itraconazole and voriconazole cross-resistance was common in vitro.

Concepts: Human, Reproduction, Evolution, Mammal, Cat, Aspergillosis, Aspergillus, Felidae

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Invasive pulmonary aspergillosis (IPA) is a life-threatening lung disease caused by the fungus Aspergillus fumigatus, and is a leading cause of invasive fungal infection-related mortality and morbidity in patients with hematological malignancies and bone marrow transplants. We developed and tested a novel probe for noninvasive detection of A. fumigatus lung infection based on antibody-guided positron emission tomography and magnetic resonance (immunoPET/MR) imaging. Administration of a [(64)Cu]DOTA-labeled A. fumigatus-specific monoclonal antibody (mAb), JF5, to neutrophil-depleted A. fumigatus-infected mice allowed specific localization of lung infection when combined with PET. Optical imaging with a fluorochrome-labeled version of the mAb showed colocalization with invasive hyphae. The mAb-based newly developed PET tracer [(64)Cu]DOTA-JF5 distinguished IPA from bacterial lung infections and, in contrast to [(18)F]FDG-PET, discriminated IPA from a general increase in metabolic activity associated with lung inflammation. To our knowledge, this is the first time that antibody-guided in vivo imaging has been used for noninvasive diagnosis of a fungal lung disease (IPA) of humans, an approach with enormous potential for diagnosis of infectious diseases and with potential for clinical translation.

Concepts: Immune system, Cancer, Disease, Infectious disease, Infection, Positron emission tomography, Aspergillosis, Aspergillus fumigatus

8

We have identified the first case of a fks1 hot spot 1 point mutation causing echinocandin resistance in a clinical Aspergillus fumigatus isolate recovered from a chronic pulmonary aspergillosis patient with an aspergilloma who first failed azole and polyene therapy, and then subsequently failed micafungin treatment.

Concepts: Medicine, Mutation, Point mutation, Aspergillosis, Aspergillus, Aspergillus fumigatus, HotSpot, Aspergilloma