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.

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.

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.

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.

Outcomes of persons with blastomycosis involving the central nervous system.

Blastomyces dermatitidis is a dimorphic fungus which is potentially life-threatening if central nervous system (CNS) dissemination occurs. Sixteen patients with proven or probable CNS blastomycosis are presented. Median duration of symptoms was 90 days; headache and focal neurologic deficit were the most common presenting symptoms. Magnetic resonance imaging (MRI) consistently demonstrated an abnormality, compared to 58% of computed tomography scans. Tissue culture yielded the pathogen in 71% of histology-confirmed cases. All patients who completed treatment of an amphotericin B formulation and extended azole-based therapy did not relapse. Initial nonspecific symptoms lead to delayed diagnosis of CNS blastomycosis. A high index of suspicion is necessary if there is history of contact with an area where B. dermatitidis is endemic. Diagnostic tests should include MRI followed by biopsy for tissue culture and pathology. Optimal treatment utilizes a lipid-based amphotericin B preparation with an extended course of voriconazole.

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.

Uncommon yeast infections in hematological patients: from diagnosis to treatment.

Invasive fungal diseases have been recognized with increasing frequency as major pathogens in patients with cancer over the past few decades, as a result of new and more aggressive anticancer treatments and supportive care, and this has been especially reported for patients suffering from hematological malignancies. In these settings, typically uncommon yeasts and filamentous fungi have recently emerged as significant human pathogens, frequently as breakthrough infections in patients receiving empirical antifungal therapy or antifungal prophylaxis and with reported high crude mortality rates. The aim of this article is to discuss certain aspects of the approach to invasive fungal diseases due to uncommon yeasts (e.g., Trichosporon spp., Blastomyces spp. and Cryptococcus spp.) in patients with hematological malignancies, focusing on epidemiology, diagnosis, treatment outcomes and the role of novel antifungal drugs (i.e., new triazoles and echinocandins).

Treatment of chronic pulmonary blastomycosis with caspofungin.

Current practice guidelines recommend that pulmonary blastomycosis be treated with antifungal agents such as amphotericin B and itraconazole. Echinocandins are not recommended because of poor in vitro activity against Blastomyces dermatitidis and lack of supporting clinical data. We report a case of chronic pulmonary blastomycosis treated successfully with caspofungin.

Blastomycosis in indiana: digging up more cases.

BACKGROUND: The endemic region of blastomycosis historically has included the state of Indiana. However, few published reports of blastomycosis exist to substantiate this distinction. A surge of patients with blastomycosis in central Indiana (Indianapolis and surrounding counties) beginning in 2005 prompted us to review our local experience. We propose that this surge was related to major highway construction around Indianapolis. METHODS: We reviewed all microbiologically confirmed cases from four hospitals serving central Indiana. Chart review was completed for adult patients, and data were collected on clinical presentations, methods of diagnosis, comorbidities, radiologic findings, treatment, and outcomes. We plotted patient residence addresses with sites of highway construction. RESULTS: Fifty-nine patients were identified from laboratory results and physician referral. Interestingly, a surge of blastomycosis incidence occurred in 34 patients between 2005 and 2008 during which time major highway projects were under way around the Indianapolis metropolitan area. The majority of these patients presented acutely and with pulmonary involvement. Fungal culture and antigen testing were the most sensitive means to diagnosis. Antifungal therapy was highly effective. CONCLUSIONS: This urban outbreak of blastomycosis in Indianapolis should prompt clinicians to consider blastomycosis in this highly endemic area of histoplasmosis.

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.

Deactivation of the dimorphic fungi Histoplasma capsulatum, Blastomyces dermatitidis and Coccidioides immitis using hydrogen peroxide vapor.

Hydrogen peroxide vapour (HPV) has been proposed as an alternative to formaldehyde fumigation for the decontamination of biosafety level (BSL) III laboratories. The aim of this study was to evaluate the efficacy of HPV against the dimorphic fungi Histoplasma capsulatum, Blastomyces dermatitidis and Coccidioides immitis. Working inside a class II biological safety cabinet (BSC) within a BSL III laboratory, inocula containing approximately 5-log(10) cfu/ml from the mould form of each organism suspended in RPMI medium were deposited on stainless steel discs and allowed to air dry. The organisms were exposed to HPV inside a BSC using a BIOQUELL ClarusS HPV generator. In three replicate experiments, individual discs were transferred into liquid media at timed intervals during a 105 minute HPV exposure period. Control- and HPV-exposed discs were incubated in RPMI media at 30 degrees C for 6 weeks to determine if any viable organisms remained. Positive cultures were confirmed using specific nucleic acid hybridization probes. Results indicate that H. capsulatum, B. dermatitidis and C. immitis were killed within 30 minutes of HPV exposure.

Extracellular calcium and magnesium, but not iron, are needed for optimal growth of Blastomyces dermatitidis yeast form cells in vitro.

In the present study, we demonstrate that the yeast form of Blastomyces dermatitidis can proliferate for short periods of time in the absence of ferric iron but not in the absence of calcium or magnesium. The results of this study shed light on the resistance of B. dermatitidis to chelating agents, such as deferoxamine, and may explain how B. dermatitidis resists the iron-binding activity of serum transferrin.

Novel role for albumin in innate immunity: serum albumin inhibits the growth of Blastomyces dermatitidis yeast form in vitro.

In this study we found that serum inhibitory activity against Blastomyces dermatitidis was principally mediated by albumin. This was confirmed in experiments using albumin from several mammalian species. Analbuminemic rat serum did not inhibit B. dermatitidis growth in vivo; however, the addition of albumin restored inhibitory activity. Inhibitory activity does not require albumin domain III and appears to involve binding of a low-molecular-weight yeast-derived growth factor.