Central nervous system blastomycosis clinical characteristics and outcomes.

Blastomycosis is a local or systemic infection, caused by Blastomyces dermatitidis (B. dermatitidis) or B. gilchristii. Blastomycosis has been described as "the great pretender," alluding to the fact that it manifests in a wide range of symptoms and disease severity. Central nervous system (CNS) involvement, although rare, carries significant mortality. Due to the limited published reports of CNS blastomycosis, we present an updated cohort with eight cases of proven or probable CNS blastomycosis describing presentation, diagnosis, treatment and outcomes. Headache was the most common presenting symptom. Magnetic resonance imaging (MRI) proved to be the superior imaging study. All patients in our cohort were diagnosed by histopathological staining or cultures of tissue or fluid obtained from CNS or extra-CNS lesions. All patients that received treatment with Liposomal amphrotericin B for at least 10 days followed by a prolonged azole therapy did not have relapse. Two patients with late diagnoses died during hospitalization. Our findings confirm the importance of timely diagnosis and treatment of CNS blastomycosis to improve outcomes especially with an azole that have a high CNS penetration and a good intrinsic activity for B. dermatitidis such as voriconazole.

In silico anti-fungal efficacy and the mechanism of binding of some Syzygium aromaticum ingredient compounds to aspartate semialdehyde dehydrogenase, 6C8W and 6C85, enzymes from Blastomyces dermatitidis.

This in silico work was carried out to reveal the proposed anti-fungal efficacy of some clove ingredient compounds against aspartate semialdehyde dehydrogenase, 6C8W and 6C85, enzymes from Blastomyces dermatitidis. The molecular docking simulation was implemented utilizing the Auto Dock 4.2. software. A set of 17 compounds were selected for this study, which is known to be active ingredients of Syzygium aromaticum crude and oil. The best docking scores associated with the Blastomyces dermatitidis enzymes 6C85 and 6C8W were for Maslinic acid and Oleanolic acid, followed by Stigmasterol and Campesterol. It was found that these compounds possess inhibitory potential against 6C85 and 6C8W and hence have anti-fungal efficacy. Maslinic acid and Oleanolic acid produced the strongest binding to 6C85 and 6C8W over the remaining bioactive compounds by forming H-bonds with some amino acids in these enzymes.

Fludioxonil Induces Drk1, a Fungal Group III Hybrid Histidine Kinase, To Dephosphorylate Its Downstream Target, Ypd1.

Novel antifungal drugs and targets are urgently needed. Group III hybrid histidine kinases (HHKs) represent an appealing new therapeutic drug target because they are widely expressed in fungi but absent from humans. We investigated the mode of action of the widely utilized, effective fungicide fludioxonil. The drug acts in an HHK-dependent manner by constitutive activation of the HOG (high-osmolarity glycerol) pathway, but its mechanism of action is poorly understood. Here, we report a new mode of drug action that entails conversion of the HHK from a kinase into a phosphatase. We expressed Drk1 (dimorphism-regulating kinase), which is an intracellular group III HHK from the fungal pathogen Blastomyces dermatitidis, in Saccharomyces cerevisiae Drk1 engendered drug sensitivity in B. dermatitidis and conferred sensitivity upon S. cerevisiae In response to fludioxonil, Drk1 behaved as a phosphatase rather than as a kinase, leading to dephosphorylation of its downstream target, Ypd1, constitutive activation of the HOG pathway, and yeast cell death. Aspartic acid residue 1140 in the Drk1 receiver domain was required for in vivo phosphatase activity on Ypd1, and Hog1 was required for drug effect, indicating fidelity in HHK-dependent drug action. In in vitro assays with purified protein, intact Drk1 demonstrated intrinsic kinase activity, and the Drk1 receiver domain exhibited intrinsic phosphatase activity. However, fludioxonil failed to induce intact Drk1 to dephosphorylate Ypd1. We conclude that fludioxonil treatment in vivo likely acts on an upstream target that triggers HHK to become a phosphatase, which dephosphorylates its downstream target, Ypd1.

One new and nine known flavonoids from Choerospondias axillaries and their in vitro antitumor, anti-hypoxia and antibacterial activities.

In the present study, a new flavanoid 1, together with nine known ones 2-10 were isolated from the stem bark of Choerospondias axillaries, the fruit of which was used mainly for treatment of cardiovascular diseases in China. The structure of 1 was established on the basis of its extensive spectral data, and the absolute structures of 1 and 10 were determined by their CD data. The absolute structure of 10 was established for the first time. Among the obtained compounds, 5-8 inhibited the proliferation of K562 cells with inhibition rates of 26.6%, 65.7%, 40.4% and 45.6% at 100 µg/mL; 1 and 4-10 showed significant protective effects on anoxia-induced injury in cultured ECV304 or PC12 cells at 50 µg/mL; 8 and 9 showed antibacterial effects on Staphylococcus aureus ATCC6538 at the tested concentration of 150 µg/8 mm paper disc. Compounds 2 and 4-10 were isolated for the first time from this genus. The proliferation inhibiting activities of 7 and 8, the anti-hypoxia activities of 1 and 4-10, and the antibacterial effect of 8 and 9 on Staphylococcus aureus ATCC6538 are reported here for the first time.

Blastomycosis in India: report of an imported case and current status.

We report a case of disseminated blastomycosis in a female resident of Delhi, who acquired the infection during travel to the USA, which was successfully treated with oral itraconazole. In addition, we present a critical literature review, indicating that blastomycosis is endemic in India but its areas of endemicity, prevalence, and the natural habitat of the etiologic agent, remain undetermined. The diagnosis of blastomycosis was made by examination of Gomori's methenamine silver stained sections of tissue obtained from a biopsy of a subcutaneous, abdominal nodular. These studies revealed thick-walled, broad-based budding yeast cells compatible with Blastomyces dermatitidis, and consistent with the isolation of the fungus in cultures inoculated with posterior auricular lymph node aspirate. Microscopically, the isolate had thin, septate hyphae and characteristic spherical to pyriform, smooth-walled microconidia. Its identity was confirmed by conversion to its typical yeast form on pea seed agar at 37°C and by DNA sequencing of ITS and BAD 1 promoter regions.

Cutaneous and disseminated blastomycosis: a pediatric case series.

Blastomycosis is a rare fungal infection that most often initially infects the lungs and can progress to disseminated involvement of the skin, bones, and central nervous system (CNS). Pediatric blastomycosis constitutes a small portion of total cases, but delay in diagnosis may result in significant morbidity. Seventeen pediatric cases of blastomycosis were identified at Children's Hospital of Wisconsin from 1999 to 2009 through retrospective chart review; 53% had evidence of dissemination (bone, skin, or CNS) confirmed by culture. Six cases presented with cutaneous lesions, and five of these were found to have other systemic involvement. These five nonimmunosuppressed cases of primary pulmonary disease with cutaneous involvement plus dissemination to bone or the CNS are reported in detail. The diagnosis of blastomycosis in children is often delayed, and dissemination by the time of diagnosis may be more common than in adults. Cutaneous dissemination may occur in immunocompetent children, may indicate underlying systemic involvement, and can be more readily identified than symptoms of bony or neurologic involvement. These reported cases indicate the importance of dermatologists recognizing and investigating all potentially involved organ systems when a patient presents with characteristic skin lesions with or without a history of respiratory illness.

[Determination of main peptide toxins from Amanita pallidorosea with HPLC and their antifungal action on Blastomyces albicans].

OBJECTIVE: To detect peptide toxins in Amanita pallidorasea and to study the antifungal activities of peptide toxins against Blastomyces albicans. METHODS: We separated and identified peptide toxins and determined its contents in the fruiting body, pileus and the mixture of stipe and volva from A. pallidorasea by HPLC and ESI-MS methods. Meanwhile, we detected antifungal activities of the crude toxin and the separated peptide toxins against Blastomyces albicans JLC31680 and JLC31681 by the paper disk method. RESULTS: We totally got three peptide toxins: alpha-amanitin (alpha-AMA), beta-amanitin (beta-AMA) and phalloidin (PHD). The contents of alpha-AMA, beta-AMA and PHD were 30.3 mg/g, 6.99 mg/g and 9.95 mg/g in fruiting body, and 45.0 mg/g, 11.1 mg/g and 11.3 mg/g in pileus. The contents of alpha-AMA and PHD were 11.7 mg/g and 7.98 mg/g in the mixture of stipe and volva , but the beta-AMA was not detected in this part. The inhibition ratio of the crude toxin and alpha-AMA, beta-AMA and PHD to B. albicans JLC31680 were 11.96%, 32.52%, 23.29% (P<0.01) and 15.46% (P<0.05). The inhibition ratio of the crude toxin and beta-AMA to B. albicans JLC31681 was 10.16% and 11.10% (P < 0.01), while that of alpha-AMA's was 6.89% (P < 0.05). CONCLUSIONS: A. pallidorasea is a new resource of peptide toxins with antifungal activity.

The role of voriconazole in the treatment of central nervous system blastomycosis.

BACKGROUND: Blastomycosis is an endemic mycosis caused by the dimorphic fungus Blastomyces dermatitidis. Although this disease primarily involves the lungs, the clinical spectrum of blastomycosis can range from subclinical infection to extrapulmonary dissemination. The central nervous system (CNS) form of blastomycosis is primarily treated with an amphotericin B formulation, but associated toxicities of this agent preclude its use in some patients. Voriconazole is a broad-spectrum triazole antifungal that has emerged as a potential treatment option for CNS blastomycosis because of its excellent penetration into the cerebrospinal fluid and brain tissue. OBJECTIVE: To evaluate evidence for the use of voriconazole in the treatment of CNS blastomycosis. DATA SOURCES: A literature search was performed using MEDLINE, EMBASE, Cochrane Database, and PubMed (all up to April 2009). Search terms included voriconazole, blastomyces, blastomycosis, CNS, cerebral, and central nervous system. STUDY SELECTION AND DATA EXTRACTION: English-language clinical trials, case reports, treatment guidelines, and background material were searched for voriconazole safety and efficacy data. References of reviewed articles were examined and used to identify additional sources. DATA SYNTHESIS: A search of the literature yielded 2 published case reports and 2 case series documenting a total of 7 cases of CNS blastomycosis. In all cases, CNS blastomycosis was successfully treated sequentially with amphotericin B followed by voriconazole. To date, no clinical trials have evaluated the use of voriconazole in treating CNS blastomycosis. Ages of the patients with documented cases of CNS blastomycosis ranged from 14 months to 63 years. In at least 5 cases, CNS blastomycosis presented as lesions in the brain detected by magnetic resonance imaging. One case presented as focal splenic lesions. The remaining 2 were diagnosed based on neuroimaging studies or positive spinal fluid serology. Prior to receiving voriconazole, patients were treated with an amphotericin B formulation combined in some situations with either fluconazole or itraconazole. Subjects underwent treatment with voriconazole for an average of 11 months, with disease remission or stabilization detected in all cases. CONCLUSIONS: Further studies are needed to fully elucidate the role of voriconazole in the treatment of CNS blastomycosis. It nonetheless may be considered as an azole option for either follow-up therapy after liposomal amphotericin B therapy or as salvage therapy in patients intolerant of amphotericin B or other azoles.

Antifungal therapeutics for dimorphic fungal pathogens.

Dimorphic fungi cause several endemic mycoses which range from subclinical respiratory infections to life-threatening systemic disease. Pathogenic-phase cells of Histoplasma, Blastomyces, Paracoccidioides and Coccidioides escape elimination by the innate immune response with control ultimately requiring activation of cell-mediated immunity. Clinical management of disease relies primarily on antifungal compounds; however, dimorphic fungal pathogens create a number of challenges for antifungal drug therapy. In addition to the drug toxicity issues known for current antifungals, barriers to efficient drug treatment of dimorphic fungal infections include natural resistance to the echinocandins, residence of fungal cells within immune cells, the requirement for systemic delivery of drugs, prolonged treatment times, potential for latent infections, and lack of optimized standardized methodology for in vitro testing of drug susceptibilities. This review will highlight recent advances, current therapeutic options, and new compounds on the horizon for treating infections by dimorphic fungal pathogens.

The iron-hydrogen peroxide-iodide system is fungicidal: activity against the yeast phase of Blastomyces dermatitidis.

A series of experiments show the potency of a newly described microbicidal system, involving iron, H2O2, and halide, in killing a fungus (Blastomyces dermatitidis). B dermatitidis has previously been shown susceptible to the myeloperoxidase-H2O2-halide system. The present studies show killing of either of two strains in 1 hour if Fe++ at 5 X 10(-5)M, H2O2 at 5 X 10(-5)M and Kl at 5 X 10(-4)M are all present (P less than 0.001). EDTA, a Fe++ chelator, abrogates killing. The mechanism presumably utilizes hydroxyl radical, since an inhibitor, ethanol, also neutralizes the system. The bactericidal and fungicidal system is of great potential importance in vivo.

Preparation and in vitro antifungal activities of some quinolizidine derived hemiaminals and beta-tert-amino sulfides.

New alpha-thiohemiaminals, 7alpha-phenylthio-7-epideoxynupharidin-6-ol, the diasteriomeric 7beta-phenylthiodeoxy-nupharidin-6-ol, and 3-methyl-3-methylthio-4-hydroxyquinolizidine, were prepared and reduced to the corresponding beta-tert-amino sulfides. The configuration at C-7 of the beta-tert-amino sulfides was determined by observing the direction of the solvent-induced shift of the C-7 methyl proton resonance. The configuration at C-7 of the new alpha-thiohemiaminals was established by correlations with the beta-tert-amino sulfides and confirmed, in the case of the deoxynupharidine derivatives, by circular dichroism and ascertaining the sterochemistry of deuteride incorporation upon sodium borodeuteride reduction of the alpha-thiohemiaminal. The in vitro antifungal activities of six compounds possessing the quinolizidine skeleton, including all the newly synthesized compounds as well as some previously reported ones, and amphotericin B were tested against several human pathogenic fungi. Besides amphotericin B, only the two deoxynupharidine alpha-thiohemiaminals were active, especially against Histoplasma capsulatum and Blastomyces dermatitidis. The observations indicate activity is derived from the 3-furyl group and the functionality from which alpha-thioimmonium ions can be produced.

Inhibition of Blastomyces dermatitidis by topical lidocaine.

This study was designed to determine if lidocaine inhibited growth of Blastomyces dermatitidis and thereby reduced recovery of the fungus from bronchoscopy specimens. Case records of 36 patients with pulmonary blastomycosis showed that when the fungus was present at microscopy, whether the specimen was sputum or bronchial washings, culture of the bronchoscopic specimen was more frequently negative than the culture of the sputum specimen (p less than .05). In addition, lidocaine was shown to inhibit growth of B dermatitidis in vitro, with the inhibition depending on the concentration of the drug and the duration of exposure (p less than .01). High concentrations of lidocaine for topical anesthesia appear to adversely affect the recovery of B dermatitidis from bronchoscopic specimens.

The efficacies of common dyes in primary isolation media for recovery of pathogenic fungi.

Dyes incorporated into a basal medium of brain heart infusion, Sabhi, tryptic soy, or yeast extract--pepton--glucose (YxPG) agar for selective isolation of fungi were investigated. Dilutions of 1:500, 1:750, 1:1,000, 1:5,000, and 1:10,000 of 33 common dyes were tested against 11 gram-positive and 16 gram-negative bacteria. In addition, these dyes were tested against Cryptococcus neoformans, Candida albicans, and the dimorphic phases of Histoplasma capsulatum and Blastomyces dermatitidis. Twenty-one of the dyes did not inhibit any of the organisms tested. Brilliant green, gentian violet, and malachite green (at three dilutions) inhibited all the organisms tested. Methyl red was found to be the best dye in selecting for fungi. Several dyes were also found to inhibit selectively C. neoformans or C. albicans and the dimorphic fungi H. capsulatum or B. dermatitidis.

Sensitivity of some human pathogenic yeasts and systemic fungi to myxin.

Myxin, a relatively new antibacterial and antifungal antibiotic, produced by a species of Sorangium, was used to investigate its effectiveness against some yeasts and dimorphic fungi associated with human diseases. Results indicated that the minimal fungicidal concentrations (MFC) of myxin for Candida albicans, C. krusei, C. parapsilosis, C. tropicalis, and Torulopsis glabrata were 0.39-6.25 mug/ml, and for C. guilliermondii and C. tropicalis 12.5-25 mug/ml. The MFC for Blastomyces dermatitidis and Sporothrix schenckii was 0.195 and 6.25 mug/ml, respectively. The MFC for these two systemic fungi for amphotericin B (fungizone) was 0.39-0.78 and 6.25 mug/ml. It seems that myxin is more effective against B. dermatitidis than amphotericin B. The isolate of Coccidioides immitis was found to be very sensitive to myxin (MFC, 0.78-1.56 mug/ml).

In vitro antifungal activity of BMS-181184 against systemic isolates of Candida, Cryptococcus, and Blastomyces species.

BMS-181184 is a water-soluble derivative of the pradimicin group of antifungal compounds. We determined the in vitro activities of BMS-181184 and comparator agents amphotericin B, 5-fluorocytosine, fluconazole, and ketoconazole against 184 systemic fungal isolates collected at the Health Sciences Centre in Winnipeg, Canada, between 1987 and 1995. BMS-181184 demonstrated MICs of between 1 and 8 micrograms/mL for all Candida albicans, Candida glabrata, Candida tropicalis, Candida krusei, Candida lusitaniae, and Cryptococcus neoformans isolates tested. BMS-181184 was less active against Candida parapsilosis (MIC90 = 16 micrograms/mL) and Blastomyces dermatitidis (MIC90 = 32 micrograms/mL). Isolates of Candida species with fluconazole MICs of > or = 16 micrograms/mL and those with fluconazole MICs of < or = 8 micrograms/mL demonstrated similar BMS-181184 sensitivities.

New azasteroidal antifungal antibiotics from Geotrichum flavo-brunneum. III. Biological activity.

The A25822 antibiotic complex consists of seven biologically active factors. A comparative study of these factors determined that factor B possessed the greatest antifungal activity. The minimal inhibitory concentration of A25822B against isolates of Candida albicans was less than 0.3 similar to 5.0 mug/ml, Trichophyton mentagrophytes was inhibited at less than 0.0312 mug/ml. Other pathogenic fungi such as Cryptococcus neoformans, Histoplasma capsulatum, Blastomyces dermatitidis, Sporotrichum schenckii, and Microsporium gypseum were very susceptible to A25822B. Only limited antibacterial activity of A25822B was found. Parenteral or oral administration of 50 mg/kg of A25822B significantly extended the average survival time of mice infected with C. albicans. Doses of 20 mg/kg of A25822B caused a greater than ten-fold reduction in the number of Candida cells recovered from kidneys of infected mice. A solution of 0.5% or 0.25% A25822B applied topically was effective against an experimental dermatophyte infection on guinea pigs. A peak blood level of 3 mug/ml was achieved in mice following a 100 mg/kg dose of A25822B. Combination of A25822B with a polyene antibiotic in vitro showed antagonism.

Antimicrobial activity of some isothiosemicarbazones.

The microbiological activity of a series of isothiosemicarbazones is reported. The experimental data relating to the microbiological screening show an interesting antibacterial activity associated to a good antifungal activity.

Synthesis and anti-microbial activity of benzo-condensed heterocyclic derivatives.

The synthesis of 2,4-dione derivatives of 1,5-benzodithiepine, 1,5-benzodiazepine and 1,5-benzothiazepine and the anti-microbial activity in vitro of these derivatives and of analogous of 1,5-benzodioxepine, 1,5-benzoxathiepine and 1,5-benzoxazepine, previously prepared, are reported. Some of these compounds showed a good activity against some Gram positive microorganisms and blastomycetes.

Blastomyces dermatitidis in a renal transplant recipient.

Fungal pathogens can be the source of serious and sometimes fatal infections following organ transplantation. To the best of our knowledge, we present the first case of cutaneous blastomycosis in a renal allograft recipient in India, a country outside the known endemic regions. This case, with the very rare and unexpected diagnosis of blastomycosis, not only reflects the tremendous diversity of infections in transplant recipients but also emphasizes the utility of serological methods even in the immunosuppressed host.