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pathological case of the month. blastomyces dermatitidis. 200111177071
viability, morphological characteristics and dimorphic ability of fungi preserved by different methods.the viability, morphological characteristics and dimorphic ability of fungi were evaluated. strain subcultures were maintained under mineral oil and in soil for different periods of time, ranging from 49 to eight years. of the 16 blastomyces dermatitidis strains, four maintained viability and were able to complete the dimorphic process to the m phase producing a large amount of conidia, but were unable to form y cells at 36 degrees c. of the 15 histoplasma capsulatum var. capsulatum strains, onl ...200115496128
fungal skin infections in organ transplant recipients.transplantation is now currently and increasingly performed for the treatment of various acute and chronic diseases. today the kidney, heart, lung, heart-lung, liver, pancreas, kidney-pancreas, small bowel and bone marrow are being transplanted. the immunological status of patients receiving such transplants exposes them to the risk of developing bacterial, viral and fungal infections. the etiological agents of mycotic diseases involving the skin of transplant recipients range from the common de ...200211817966
review of the safety and efficacy of voriconazole.voriconazole is a new triazole antifungal agent structurally related to fluconazole, but with improved potency and spectrum of activity. voriconazole has good in vitro activity against candida species, cryptococcus neoformans, aspergillus spp. and other mould spp. initial clinical studies and case reports demonstrate efficacy with voriconazole against invasive aspergillosis and infections caused by c. neoformans, scedosporium apiospermum, blastomyces dermatitidis, coccidioides immitis and histop ...200211866669
pulmonary blastomycosis: an appraisal of diagnostic techniques.pulmonary blastomycosis often mimics bacterial pneumonia or bronchogenic carcinoma, which may result in delayed therapy or the performance of unnecessary diagnostic procedures. we have reviewed the utilization of diagnostic techniques in the workup of patients with pulmonary blastomycosis, defined their diagnostic yields, and proposed an optimal diagnostic approach for the patient in whom pulmonary blastomycosis is considered.200211888958
epidemiology and clinical spectrum of blastomycosis diagnosed at manitoba hospitals.blastomyces dermatitidis is a dimorphic fungus endemic to canada and the united states. few reports regarding blastomycosis in canada have been published. we retrospectively reviewed the medical charts of 143 patients with confirmed cases of blastomycosis diagnosed in hospitals in manitoba, canada, from 1988 through 1999. the annual incidence rate of blastomycosis in manitoba was 0.62 cases per 100,000 population, compared with 7.11 cases per 100,000 population in the kenora, ontario district. t ...200211981725
transferrin independent serum inhibition of blastomyces dermatitidis.human serum has been reported to inhibit the growth of several fungal pathogens. serum inhibitory activity has predominantly been associated with transferrin-mediated iron binding. we found that serum from several animal species (human, dog, mouse and fetal bovine) inhibited the growth of the dimorphic fungal pathogen, blastomyces dermatitidisin vitro. in initial studies, we found no correlation between the total iron-binding capacity of various sera and their inhibitory activity against b. derm ...200211812214
using new genetic tools to study the pathogenesis of blastomyces dermatitidis.fungal pathogens have emerged as a public health menace owing to the expanding population of vulnerable patients and a heightened exposure to fungi in our environment, particularly for the systemic dimorphic fungi that inhabit soil worldwide. a better understanding of these invaders and their pathogenic mechanisms is badly needed to further research into therapeutic options. advances in the molecular tools available for genetic manipulation of blastomyces dermatitidis have enhanced our ability t ...200211755082
cluster of pulmonary blastomycosis in a rural community: evidence for multiple high-risk environmental foci following a sustained period of diminished precipitation.much of our understanding of the epidemiologic features of infection with blastomyces dermatitidis has come from cluster and outbreak investigations which have established the association of human disease with recreational pursuits and the presence of infectious microfoci in areas of moist soil with high organic content. this report describes the clustering of eight cases of pulmonary blastomycosis without an apparent common source exposure which occurred during a 90 day period in a 96 square mi ...200211998870
serological differences in two blastomyces dermatitidis isolates from different geographical regions of north america.yeast phase lysate antigens were prepared from two isolates (t-58 and erc-2) from different geographic locations. tennessee and wisconsin. these lysate were evaluated with respect to their ability to detect antibody in dogs infected with blastomycosis and rabbits immunized with the lysates by an enzyme linked immunosorbent assay (elisa). both the dog sera and rabbit sera assays demonstrated that there were serological differences in these two isolates, which implied that there was antigenic vari ...200211998876
bad1, an essential virulence factor of blastomyces dermatitidis, suppresses host tnf-alpha production through tgf-beta-dependent and -independent mechanisms.we investigated how bad1, an adhesin and virulence factor of blastomyces dermatitidis, suppresses phagocyte proinflammatory responses. wild-type yeast cocultured with murine neutrophils or macrophages prompted release of a soluble factor into conditioned supernatant that abolished tnf-alpha production in response to the fungus; isogenic, attenuated bad1 knockout yeast did not have this effect. phagocytes released 4- to 5-fold more tgf-beta in vitro in response to wild-type yeast vs bad1 knockout ...200212023375
a technique for creating localized subcutaneous blastomyces granulomas in rats.our purpose was to develop a simple, reliable method for creating subcutaneous blastomyces dermatitidis nodules in rats and to describe the histologic appearance of these lesions. we used b. dermatitidis isolated from a dog with blastomycosis to prepare a blastomyces yeast suspension. four rats were used to test initial dose concentrations of 10(5), 10(6), 10(9), and 10(10) yeast organisms. the dose was administered subcutaneously over the distal tibia in a volume of 0.1 ml. we then inoculated 3 ...200212051658
voriconazole -- better chances for patients with invasive mycoses.the past two decades have witnessed an increase in serious fungal infections, without corresponding growth in available antifungal agents. voriconazole (vrc) is a novel triazole antifungal, recently approved in europe for treatment of serious infections caused by aspergillus, fusarium, scedosporium, and resistant candida species. voriconazole has in vitro activity against yeasts and yeast-like fungi similar, or superior to, fluconazole (flc), itraconazole (itc) and amphotericin b (amb). candida ...200212069915
pulmonary thromboembolism associated with blastomyces dermatitidis in a dog.an 8-year-old, male castrated golden retriever presented for cough and increased respiratory effort. radiographs revealed an alveolar pattern in the right caudal lung lobe and an opacity at the carina suspected to be enlarged tracheobronchial lymph nodes. the disease progressed to involve the right middle lung lobe. cytopathology of a fine-needle aspirate and bronchoalveolar lavage fluid were nondiagnostic. surgical removal of the right caudal lung lobe and biopsy of the perihilar lymph nodes re ...200212220026
delayed diagnosis of osseous blastomycosis in two patients following environmental exposure in nonendemic areas.blastomycosis generally results from inhalation of blastomyces dermatitidis conidia following exposure to contaminated soil in an endemic area. primary infections commonly involve the lungs, although secondary dissemination to other body sites may occur. we describe 2 cases of osseous blastomycosis in people living outside the endemic areas. both patients reported exposure to soilfollowing injury to the knee from occupational activities. mold isolated from each case was identified as b dermatiti ...200212375640
detection of cell wall galactomannoprotein afmp1p in culture supernatants of aspergillus fumigatus and in sera of aspergillosis patients.mannoproteins are important and abundant structural components of fungal cell walls. the afmp1 gene encodes a cell wall galactomannoprotein of aspergillus fumigatus. in the present study, we show that afmp1p is secreted into the cell culture supernatant at a level that can be detected by western blotting. a sensitive enzyme-linked immunosorbent assay (elisa) developed with antibodies against afmp1p was capable of detecting this protein from the cell culture supernatant of a. fumigatus. the anti- ...200212409437
molecular genetic analysis of blastomyces dermatitidis reveals new insights about pathogenic mechanisms.fungal pathogens have emerged as a public health menace owing to the expanding population of vulnerable patients and to a heightened exposure to fungi in our environment, particularly for the systemic dimorphic fungi that inhabit soil worldwide. a better understanding of these microbes and their pathogenic mechanisms is badly needed to further research into therapeutic options. advances in the molecular tools for genetic manipulation of blastomyces dermatitidis have enhanced our ability to study ...200212452282
cutaneous lesions showing giant yeast forms of blastomyces dermatitidis.the yeast forms of blastomyces dermatitidis usually range from 8 to 15-20 micro m in diameter. larger yeast forms have previously been reported only twice in immunosuppressed patients. in both patients these large forms were seen within the lung.200212453301
requisite elements in vaccine immunity to blastomyces dermatitidis: plasticity uncovers vaccine potential in immune-deficient hosts.understanding fundamental mechanisms of vaccine immunity will allow proper use and optimization of vaccines. vaccination with a genetically engineered, live, attenuated strain of blastomyces dermatitidis carrying a targeted deletion at the bad1 locus confers sterilizing immunity against experimental lethal pulmonary infection. we found in this study that alphabeta t cells are requisite for durable vaccine immunity, whereas other t and b cells are dispensable. in immune-competent animals, cd4(+) ...200212471131
serological differences in three blastomyces dermatitidis strains.yeast phase lysate antigens, prepared from three isolates of blastomyces dermatitidis (t-58, tennessee dog; 48089, zaire human; erc-2, wisconsin dog) were assayed for their ability to detect antibodies in human sera, dog sera and sera from rabbits immunized with each of the lysate antigens. the dog sera were from animals diagnosed with blastomycosis from various endemic regions in north america. t-58 and erc-2 lysate antigens exhibited a high reactivity with the serum from dogs infected with bla ...200212472717
agrobacterium tumefaciens integrates transfer dna into single chromosomal sites of dimorphic fungi and yields homokaryotic progeny from multinucleate yeast.the dimorphic fungi blastomyces dermatitidis and histoplasma capsulatum cause systemic mycoses in humans and other animals. forward genetic approaches to generating and screening mutants for biologically important phenotypes have been underutilized for these pathogens. the plant-transforming bacterium agrobacterium tumefaciens was tested to determine whether it could transform these fungi and if the fate of transforming dna was suited for use as an insertional mutagen. yeast cells from both fung ...200212477790
blastomycosis of the vocal folds with life-threatening upper airway obstruction: a case report.blastomycosis is a chronic fungal disease that primarily affects the lower respiratory tract. the acute inflammatory phase of the primary pulmonary infection is characterized by a lymphohematogenous spread to extrapulmonary sites, especially the skin. the presence of disseminated infection with blastomyces dermatitidis in the larynx is unusual. in areas of the united states where this fungus is endemic, failure to consider laryngeal involvement might lead to inappropriate therapy and thus worsen ...200212516383
comparison of seven blastomyces dermatitidis antigens for the detection of antibodies in humans with occupationally acquired blastomycosis.yeast phase lysate antigens, prepared from seven isolates of blastomyces dermatitidis (dogs, t-58, m-98; human, le; soil, s; sea lion, sl; polar bear, pb; cat, c) were assayed by enzyme-linked immunosorbent assay (elisa) to detect antibodies in human sera. the sera were from individuals potentially exposed to b. dermatitidis while working on a prairie dog relocation project in colorado. all antigens exhibited greatest reactivity with three specimens in two separate assays. absorbance values rang ...200212572716
blastomycosis acquired by three children in toronto.three paediatric cases of blastomycosis, apparently acquired in or near toronto, ontario, a region not known to be endemic for this disease, are described. blastomycosis was not suspected clinically in any of the three cases, and the diagnosis was established only when the diagnostic net was broadened to include fungal and mycobacterial cultures. all three patients were diagnosed after significant delays, which is consistent with the rarity of the disease in children and its acquisition outside ...200218159399
pcr assay for identification of histoplasma capsulatum based on the nucleotide sequence of the m antigen.the major diagnostic antigens of histoplasma capsulatum var. capsulatum are the h and m antigens, pluripotent glycoproteins that elicit both humoral and t-cell-mediated immune responses. the gene encoding the m antigen has previously been sequenced, and its sequence has significant overall homology to those of the genes for fungal catalases. regions of the m-antigen gene with little or no homology were used to design four oligonucleotide sequences for application in the pcr detection and identif ...200312574242
direct invasion of bones by highly pathogenic fungi in an in vitro model and its ecological significance.animal bones after being devitalized at death are strongly resistant to wear and tear and remain in the soil or environment much longer than other organic components from dead animals. yet over the course of time they seem to disappear and thus our ecological surroundings are not cluttered with bone remnants. mechanical factors creating compression or friction and chemical factors like ph of the soil and surroundings must together have provided concerted degrading effects. microorganisms in the ...200312590255
in vitro antifungal activity of micafungin (fk463) against dimorphic fungi: comparison of yeast-like and mycelial forms.the characteristics of in vitro micafungin (fk463) antifungal activity against six species of dimorphic fungi were investigated in accordance with the nccls m27-a microdilution methods. mics of micafungin, amphotericin b, itraconazole, and fluconazole for histoplasma capsulatum var. capsulatum, blastomyces dermatitidis, paracoccidioides brasiliensis, penicillium marneffei, and sporothrix schenckii were determined both for the yeast-like form and mycelial form. coccidioides immitis was tested onl ...200312654673
a c-terminal egf-like domain governs bad1 localization to the yeast surface and fungal adherence to phagocytes, but is dispensable in immune modulation and pathogenicity of blastomyces dermatitidis.bad1, an adhesin and immune modulator of blastomyces dermatitidis, is an essential virulence factor that is released extracellularly before association with the yeast surface. here, deletion of the c-terminal egf-like domain profoundly affected bad1 function, leading to non-association with yeast, extracellular accumulation and impaired yeast adherence to macrophages. in equilibrium binding assays, deltac-term bad1, lacking an egf-like domain, bound poorly to bad1 null yeast, yielding a low affi ...200312657044
blastomycosis.blastomycosis is an endemic mycoses in the central united states caused by a dimorphic fungus, blastomyces dermatitidis, that exists in nature in mycelial phase and converts to yeast phase at body temperature. the organism may produce epidemics of infection following a point source of infection or sporadic endemic infection. blastomycosis can be a subclinical illness with subsequent protection against progressive infection afforded by cellular immune mechanisms, but it may present with progressi ...200312751259
vaccine immunity to pathogenic fungi overcomes the requirement for cd4 help in exogenous antigen presentation to cd8+ t cells: implications for vaccine development in immune-deficient hosts.systemic fungal infections with primary and opportunistic pathogens have become increasingly common and represent a growing health menace in patients with aids and other immune deficiencies. t lymphocyte immunity, in particular the cd4+ th 1 cells, is considered the main defense against these pathogens, and their absence is associated with increased susceptibility. it would seem illogical then to propose vaccinating these vulnerable patients against fungal infections. we report here that cd4+ t ...200312782709
giant blastoconidia of candida albicans. a case report and review of the literature.we describe a patient with extranodal non-hodgkin lymphoma who developed systemic candidiasis after treatment with a cyclophosphamide-based chemotherapy regimen. histologically, the fungal organisms demonstrated markedly enlarged blastoconidia with a variety of morphologic forms, mimicking other mycotic organisms, such as cryptococcus neoformans, blastomyces dermatitidis, and paracoccidioides brasiliensis. the in vivo occurrence of such giant forms is rare, and when observed histologically may r ...200312823045
nested pcr assays for detection of blastomyces dermatitidis dna in paraffin-embedded canine tissue.a blastomyces dermatitidis nested pcr assay targeting the gene encoding the wisconsin 1 (wi-1) adhesin was developed and compared with a nested pcr targeting the 18s rrna gene (rdna) of members of the family onygenaceae: we examined 73 paraffin-embedded tissue samples obtained from nine dogs which died of blastomycosis and nine dogs which succumbed to lymphosarcoma according to autopsy findings; amplifiable canine dna was extracted from 25 and 33 specimens from the two groups, respectively. the ...200312517849
disseminated blastomycosis.a 26-year-old veiled saudi-arabian woman presented with hemoptysis, and multiple nodules and abscesses. a skin biopsy specimen revealed yeast forms consistent with blastomyces dermatitidis. fungal cultures from bronchoscopy and skin specimens also grew b dermatitidis. she was treated with oral itraconazole (200 mg twice a day). both lung and skin lesions showed improvement within 6 weeks.200312522382
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.200314573690
blastomycosis in nondomestic felids.blastomycosis was diagnosed in six nondomestic felids from eastern tennessee, including two asian lions (panthera leo persicus), one african lion (panthera leo), one siberian tiger (panthera tigris), one cheetah (acinonyx jubatus), and one snow leopard (panthera uncia). clinical signs included lethargy, anorexia, weight loss, dyspnea, sneezing. ataxia, and paresis. variable nonspecific changes included leukocytosis, monocytosis, moderate left shift of neutrophils, moderate hypercalcemia, hyperpr ...200314582783
diagnostic peritoneal lavage for identification of blastomycosis in a dog with peritoneal involvement.a 6-year-old castrated male dalmatian was evaluated because of hematemesis. the dog had lived its entire life in south dakota and wyoming and had never traveled outside of these states. results of laboratory testing were compatible with iatrogenic acute renal failure and gastrointestinal tract ulceration secondary to previous nonsteroidal anti-inflammatory drug and corticosteroid administration. differential diagnoses for clinical signs and laboratory abnormalities that existed prior to these tr ...200314664450
an imported case of blastomyces dermatitidis infection in mexico.blastomycosis is an acute or chronic primary infection of the respiratory system, endemic in north america (united states of america and canada), africa and asia. we report a case in mexico, in a three years old child who had been born in california and lived in chicago, u.s.a. the patient presented pulmonary symptoms prior to development of a skin ulcer. blastomyces dermatitidis was identified by mycological and molecular procedures. the patient was successfully treated with amphotericin b, ora ...200314682449
blastomyces dermatitidis lysate antigens: antibody detection in serial serum specimens from dogs with blastomycosis.yeast phase lysate antigens prepared from different isolates of blastomyces dermatitidis (t-58, dog-tennessee; t-27, polar bear-tennessee; erc-2, dog-wisconsin; er-3, woodpile-wisconsin) were compared with respect to the detection of antibodies (indirect enzyme-linked immunosorbent assay-elisa, peroxidase system) in 126 serial serum specimens (pre-treatment, 30 and 60 days post-treatment with itraconazole) from 42 dogs with diagnosed blastomycosis. mean absorbance values observed with the four l ...200314682453
exploiting type 3 complement receptor for tnf-alpha suppression, immune evasion, and progressive pulmonary fungal infection.tnf-alpha is crucial in defense against intracellular microbes. host immune cells use type 3 complement receptors (cr3) to regulate excess tnf-alpha production during physiological clearance of apoptotic cells. bad1, a virulence factor of blastomyces dermatitidis, is displayed on yeast and released during infection. bad1 binds yeast to macrophages (mphi) via cr3 and cd14 and suppresses tnf-alpha, which is required for resistance. we investigated whether blastomyces adhesin 1 (bad1) exploits host ...200415585870
preventative and therapeutic vaccines for fungal infections: from concept to implementation.many challenges confront the development of fungal vaccines for humans including differences in host susceptibility, varied pathogenic mechanisms employed by the different species of fungi and mechanisms of host resistance. hence, no single antigen can be expected to serve as a pan fungal vaccine. instead, it is likely that progress for fungal vaccines will have to be made at the level of each individual organism. in recent years, tremendous strides have been made in understanding the immunopath ...200415606355
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.200415013999
comparative serological evaluation of 10 blastomyces dermatitidis yeast phase lysate antigens from different sources.yeast phase lysate antigens from 10 isolates of blastomyces dermatitidis (dog, erc-2 and t-58; t-27, polar bear; woodpile, er-3; bat lung, 48938; human, b5929, b5895, b5896, b5931, and capp) from different geographical regions, in addition to a histoplasma capsulatum (g217b) lysate preparation were compared with respect to their reactivity against serum specimens from dogs, rabbits and humans positive for blastomycosis using an indirect enzyme-linked immunosorbent assay. in addition, the lysate ...200415078431
comparison of histologic lesions of endophthalmitis induced by blastomyces dermatitidis in untreated and treated dogs: 36 cases (1986-2001).to compare prevalence of organisms and histologic changes in eyes from dogs with blastomycosis that were either untreated or undergoing treatment with itraconazole.200415112782
interaction of blastomyces dermatitidis, sporothrix schenckii, and histoplasma capsulatum with acanthamoeba castellanii.several dimorphic fungi are important human pathogens, but the origin and maintenance of virulence in these organisms is enigmatic, since an interaction with a mammalian host is not a requisite for fungal survival. recently, cryptococcus neoformans was shown to interact with macrophages, slime molds, and amoebae in a similar manner, suggesting that fungal pathogenic strategies may arise from environmental interactions with phagocytic microorganisms. in this study, we examined the interactions of ...200415155655
sequence elements necessary for transcriptional activation of bad1 in the yeast phase of blastomyces dermatitidis.blastomyces dermatitidis is a dimorphic fungal pathogen that converts from mycelia or conidia to a host-adapted yeast morphotype upon infection. conversion to the yeast form is accompanied by the production of the virulence factor bad1. yeast-phase-specific expression of bad1 is transcriptionally regulated, and its promoter shares homology with that of the yeast-phase-specific gene yps3 of histoplasma capsulatum. serial truncations of the bad1 upstream region were fused to the lacz reporter to d ...200415189999
evaluation of the in vitro and in vivo dimorphism of sporothrix schenckii, blastomyces dermatitidis, and paracoccidioides brasiliensis isolates after preservation in mineral oil.morphological differentiation has commanded attention for its putative impact on the pathogenesis of invasive fungal infections. we evaluated in vitro and in vivo the dimorphism from mycelial to yeast-phase of sporothrix schenckii, blastomyces dermatitidis and paracoccidioides brasiliensis isolates, two strains for each species, preserved in mineral oil. s. schenckii strains showed typical micromorphology at 25 degrees c but one strain was unable to complete the dimorphic process in vitro. after ...200415284890
blastomycosis: a case study of a dimorphic fungal disease.a 17-year-old male presented to a local hospital with symptoms of pneumonia and a hacking cough productive of yellow sputum. direct examination of a bronchial lavage sample revealed organisms morphologically consistent with blastomyces dermatitidis, which was confirmed by culture. the patient was placed on intravenous antifungal therapy and his condition improved dramatically. objectives: to describe the gross and microscopic morphologies of both yeast and mold forms of b. dermatitidis; to ident ...200415314888
blastomyces dermatitidis produces melanin in vitro and during infection.melanin is made by several important pathogenic fungi and is implicated in the pathogenesis of a number of mycoses. this study investigates whether the thermally dimorphic fungal pathogen blastomyces dermatitidis produces melanin. using techniques developed to study melanization in other fungi, we demonstrate that b. dermatitidis conidia and yeast produce melanin in vitro and that yeast cells synthesize melanin or melanin-like pigment in vivo. melanization reduced susceptibility to amphotericin ...200415451118
[cutaneous blastomycosis: description of two cases in tunisia].blastomycosis is an uncommon mycotic infection in africa. isolated cutaneous disease is extremely rare. the purpose of this report is to describe 2 cases of cutaneous blastomycosis. the first case involved a 70-year-old rural woman who presented papulonodules associated with scars on the upper extremities and right leg, ongoing for 2 months. the second patient was a 47-year-old woman who presented 2 vegetating plaque areas above the left knee and on the left shoulder, ongoing for 4 months. in ad ...200415460151
antigen assay with the potential to aid in diagnosis of blastomycosis.we report results of an immunoassay for blastomyces dermatitidis antigenuria. sensitivity was 92.9%, and specificity was 79.3%. cross-reactions occurred in 96.3% of patients with histoplasmosis, 100% of patients with paracoccidioidomycosis, 70% of patients with penicilliosis marneffei, 2.9% of patients with cryptococcosis, and 1.1% of patients with aspergillosis. reproducibility was 96.3%. these findings support a potential role for antigen testing in blastomycosis.200415472368
blastomycosis.blastomycosis is an endemic fungal infection predominantly seen in the south central and mid-western united states and portions of canada. the disorder is caused by blastomyces dermatitidis, a dimorphic organism usually acquired through inhalation of aerosolized conidia. most acutely infected patients are asymptomatic or develop a self-limited respiratory illness. chronic pneumonia is the dominant clinical manifestation of blastomycosis, although extrapulmonary disease is common, usually involvi ...200416088455
[mycoses of the head and neck].in recent years, mycoses have emerged as important infections in clinical practice. this phenomenon is explained by the ever growing number of immunocompromised patients and the increasing number of people travelling in areas where fungal diseases are endemic. head and neck infections are common in disseminated mycoses and may simulate carcinoma or cause upper airway obstruction. the most frequent causative yeasts or yeast-like organisms include candida albicans, cryptococcus neoformans, histopl ...200516142162
blastomyces dermatitidis antigen detection in urine specimens from dogs with blastomycosis using a competitive binding inhibition elisa.a competitive binding inhibition enzyme linked immunosorbent assay (elisa) was used to detect blastomyces dermatitidis antigens in urine specimens from dogs with blastomycosis. sera from rabbits immunized with b. dermatitidis killed whole yeast cells were used as the primary antibody in the competitive elisa. this initial study was performed to determine if b. dermatitidis antigen detection was possible and to test the efficacy of the rabbit sera as a primary antibody. an indirect elisa was also ...200516170609
progress in vaccination for histoplasmosis and blastomycosis: coping with cellular immunity.human infection with histoplasma capsulatum or blastomyces dermatitidis is sufficiently frequent to warrant exploring the development of vaccines. this review examines the advancements that have been accomplished over the last few years. the availability of molecular tools to create recombinant antigens or mutant strains has produced a small number of useful vaccine candidates. more importantly, the studies summarized herein demonstrate that understanding the host response to a protein or mutant ...200516178365
attempted isolation of blastomyces dermatitidis from native shrews in northern wisconsin, usa.the precise ecological niche of blastomyces dermatitidis is unknown. the related dimorphic fungus, paracoccidioides brasiliensis, has been isolated from south american ground-dwelling insectivorous armadillos. we attempted to isolate blastomyces from shrews, north american ground-dwelling insectivores that have been shown to harbor histoplasma capsulatum in endemic areas. forty-seven masked shrews (sorex cinereus) and 13 northern short-tailed shrews (blarina brevicauda) were collected in endemic ...200516178369
immunological basis for susceptibility and resistance to pulmonary blastomycosis in mouse strains.the immunological basis for a >10-fold resistance of outbred cd-1 mice compared to inbred balb/c mice to pulmonary blastomycosis was investigated. bronchoalveolar macrophages (bam) from cd-1 mice killed yeast cells of blastomyces dermatitidis (bd) by 25% and this increased to 59% when activated by ifn-gamma. in contrast, bam from balb/c mice lacked significant killing (5%) of bd but could be activated by ifn-gamma for enhanced killing (19%). peritoneal macrophages (pm) from cd-1 mice had signifi ...200516183299
secondary intracerebral blastomycosis with giant yeast forms.secondary central nervous system (cns) blastomycosis is an unusual manifestation of blastomycosis. we report a case of recurrent intracerebral blastomycosis that presented histopathologically with giant yeast-like cells and multinucleation that mimicked coccidioides immitis. the yeast forms of blastomyces dermatitidis usually range in size from 8 to 20 microm in diameter. large or giant yeast forms (20-40 microm) are rare. the four cases previously reported in the literature involving giant yeas ...200516205975
il-12 is required for induction but not maintenance of protective, memory responses to blastomyces dermatitidis: implications for vaccine development in immune-deficient hosts.cellular immunity mediated by t lymphocytes, in particular cd4(+) and cd8(+) type 1 (t1) cells, is the main defense against pathogenic fungi. il-12 initiates t1 cell development and cell-mediated immunity, but it is unclear whether il-12 contributes to the maintenance of an antifungal t1 response. in this study, we addressed the role of il-12 for vaccine-induced memory t cell development against experimental pulmonary blastomycosis. cd4(+) t cells absolutely required il-12 to control a live gene ...200516210634
cd28 is required for optimal induction, but not maintenance, of vaccine-induced immunity to blastomyces dermatitidis.cellular immunity mediated by t lymphocytes, in particular cd4+ and cd8+ type 1 cells, is the main defense against pathogenic fungi. here, cd28-deficient (cd28-/-) mice were used to study the role of costimulation for the generation and maintenance of t-cell-mediated, type 1 cytokine-dependent mechanisms of vaccine immunity to blastomyces dermatitidis infection. disruption of cd28 costimulation reduced the number of type 1 cd4 and cd8 cells generated and impaired resistance to infection. type 1 ...200516239544
calcium binding by the essential virulence factor bad-1 of blastomyces dermatitidis.bad-1 (blastomyces adhesin 1), a 120-kda protein of blastomyces dermatitidis, functions as an adhesin, immune modulator, and essential virulence factor. structurally, bad-1 is composed of a short n-terminal region, a core of 30 tandem repeats critical for virulence, and a c-terminal epidermal growth factor domain that binds the protein to yeast cell surface chitin. each of the 30 acidic residue-rich tandem repeats contains a sequence that resembles the calcium-binding loop of the ef-hand domain ...200516243837
epidemiology, diagnosis, and treatment of blastomycosis in dogs and cats.blastomycosis is one of the most common systemic fungal diseases in dogs in north america, but it is rarely diagnosed in cats. the typical route of infection is inhalation of aerosolized conidia of blastomyces dermatitidis. from the respiratory tract, the developing yeast form may disseminate throughout the body and affect multiple organ systems, most commonly the lymphatic, skeletal and central nervous systems, eyes and skin. disseminated disease often is associated with nonspecific signs of il ...200516317913
[mycoses of the head and neck].the ever growing number of immunocompromized patients and increasing travel to areas where fungal diseases are endemic explain why in recent years mycoses have emerged as important infections in clinical practice. it is essential that pathologists and clinicians be knowledgeable about them.200516439931
paradise -- not without its plagues: overwhelming blastomycosis pneumonia after visit to lakeside cottages in northeastern ontario.visiting lakes and cottages is a common leisure activity during summer among most canadians and paradise for some. various leisure activities are involved during these visits, including cleaning and 'airing' the cottage after long-winters, activities at the lakes and dock building etc, exposing the canadians to moist soil and decaying woods -- a source of white or tan mould -- blastomyces dermatitidis that may cause a flu-like illness to severe pneumonia that often remains a diagnostic challenge ...200515871735
fungal infections as a complication of therapy for sarcoidosis.treatment of symptomatic sarcoidosis usually includes systemic immunosuppressive agents. these agents may render the patient more susceptible to opportunistic infections. in addition, the fungal infection may be difficult to distinguish from the underlying sarcoidosis.200515879444
glutathione-dependent extracellular ferric reductase activities in dimorphic zoopathogenic fungi.in this study, extracellular glutathione-dependent ferric reductase (gsh-fer) activities in different dimorphic zoopathogenic fungal species were characterized. supernatants from blastomyces dermatitidis, histoplasma capsulatum, paracoccidioides brasiliensis and sporothrix schenckii strains grown in their yeast form were able to reduce iron enzymically with glutathione as a cofactor. some variations in the level of reduction were noted amongst the strains. this activity was stable in acidic, neu ...200516000713
in vitro activities of new and established triazoles against opportunistic filamentous and dimorphic fungi.the in vitro activities of three new triazoles were determined and compared to those of itraconazole and fluconazole against 306 clinical isolates of blastomyces dermatitidis, cladophialophora carrionii, coccidioides immitis, fonsecaea pedrosoi, fusarium spp., histoplasma capsulatum, paecilomyces lilacinus, pseudallescheria boydii and sporothrix schenckii. minimum inhibitory concentrations (mic) were determined by a broth macrodilution method of the national committee for clinical laboratory sta ...200516010855
coccidioidomycosis and blastomycosis: advances in molecular diagnosis.clinical isolates of coccidioides spp. and blastomyces dermatitidis can be identified by chemiluminescent dna probes and pcr assays targeting multicopy genes. in fixed tissue samples, cells of the two fungi are specified by in situ hybridization and pcr assays targeting 18s rdna but sequencing of the products is mandatory. nested pcr assays targeting genes encoding species- or genus-specific proteins like proline rich antigen of coccidioides spp. and b. dermatitidis adhesin facilitate amplificat ...200516043334
urine polymerase chain reaction is not as sensitive as urine antigen for the diagnosis of disseminated histoplasmosis.we developed a colorimetric microtiter plate polymerase chain reaction enzyme immunoassay (pcr-eia) for the detection of histoplasma capsulatum in urine. the specificity of the pcr assay was confirmed using h. capsulatum (positive control) and blastomyces dermatitidis (negative control) isolates. the analytical sensitivity of the pcr assay was determined by testing urine samples spiked with freshly grown h. capsulatum organisms and was 2 yeasts per reaction in urine and 0.2 yeasts per reaction i ...200616466889
phylogenetic and evolutionary aspects of paracoccidioides brasiliensis reveal a long coexistence with animal hosts that explain several biological features of the pathogen.the habitat of the mycelial saprobic form of paracoccidioides brasiliensis, which produces the infectious propagula, has not been determined and has proven difficult for mycologists to describe. the fungus has been rarely isolated from the environment, the disease has a prolonged latency period and no outbreaks have been reported. these facts have precluded the adoption of preventive measures to avoid infection. the confirmation of natural infections in nine-banded armadillos (dasypus novemcinct ...200616473563
blastomycosis in ontario, 1994-2003.we describe a case of blastomycosis in an 8-year-old boy with blastomyces-associated osteomyelitis and possible pulmonary involvement. we also identify 309 cases of blastomycosis in ontario that were seen during a 10-year period, 57% of which occurred from 2001 to 2003. the overall incidence during the study period was 0.30 cases per 100,000 population. most patients were from north ontario (n = 188), where the incidence was 2.44 cases per 100,000. the incidence in the toronto region was 0.29 pe ...200616494754
fungal infections of the spine.fungal infections of the spine are relatively uncommon. fungi such as coccidioides immitis and blastomyces dermatitidis are limited to specific geographical areas whereas cryptococcus, candida, and aspergillus are found worldwide. candida and aspergillus are normal commensals of the body and produce disease in susceptible organisms when they gain access to the vascular system through intravenous lines, during implantation of prosthetic devices, or during surgery. for the other fungi, spinal invo ...200616523132
systemic blastomycosis in a horse.progressive multisystemic disease caused by blastomyces dermatitidis was diagnosed in a 17-year-old quarter horse broodmare. the mare had been treated unsuccessfully with antibiotics for mastitis 3 months postpartum. the disease progressed to exudative cutaneous lesions affecting the ventrum, pectoral region, and limbs accompanied by weight loss across several months. yeast bodies were observed in swabs of the cutaneous exudate, suggesting a clinical diagnosis of blastomycosis. following referra ...200617121096
pcr-based detection of dna from the human pathogen blastomyces dermatitidis from natural soil samples.blastomyces dermatitidis is the dimorphic fungal agent of blastomycosis, a disease that primarily affects humans and dogs. the clinical appearance of this mycosis is well characterized, but there is still little known about its environmental niche, having been isolated from nature only 21 times. we have developed a pcr-based assay to detect b. dermatitidis from soil samples using primers specific to a portion of the promoter region of the bad1 virulence gene. an internal standard control, ptjv2, ...200617127631
blastomycosis in a young african man presenting with a pleural effusion.blastomyces dermatitidis is a dimorphic fungus endemic to north-western ontario, manitoba and some parts of the united states. the fungus is also endemic to parts of africa. pulmonary and extrapulmonary findings of a 24-year-old african man who presented with weight loss, dry cough and chronic pneumonia not resolving with antibiotic treatment are presented. the unusual occurrence of pulmonary blastomycosis associated with skin lesions and a moderate pleural effusion is reported.200617149463
chronic disseminated cutaneous blastomycosis in an 11-year old, with a brief review of the literature.chronic disseminated cutaneous blastomycosis is rare in children. we discuss an 11-year-old immunocompetent boy who presented with a history of persistent and multiple skin lesions of >1 year's duration. these lesions proved to be secondary to chronic blastomyces dermatitidis infection. complete resolution of clinical disease occurred after a 6-month course of oral itraconazole. we also present a brief review of the literature focusing on the epidemiology, manifestations, diagnosis, and treatmen ...200617155995
cardiovascular involvement in 8 dogs with blastomyces dermatitidis infection.blastomycosis is a common systemic fungal infection in dogs.200617186849
recurrent central nervous system blastomycosis in an immunocompetent child treated successfully with sequential liposomal amphotericin b and voriconazole.central nervous system involvement in infection with blastomyces dermatitidis is uncommon, except in immunocompromised patients. we report a case of central nervous system blastomycosis occurring 18 months after treatment of pulmonary blastomycosis in an immunocompetent child. our patient was successfully treated sequentially with liposomal amphotericin b followed by oral voriconazole without need for surgical resection.200616567998
differential requirements of t cell subsets for cd40 costimulation in immunity to blastomyces dermatitidis.cell-mediated immunity and production of type 1 cytokines are the main defenses against pathogenic fungi. ligation of cd40 by cd40l on t cells is critical for the induction of these immune responses in vivo. we explored the role of cd40/cd40l interactions in vaccine immunity to blastomyces dermatitidis by immunizing cd40(-/-) and cd40l(-/-) mice and analyzing their resistance to reinfection in a murine pulmonary model. in the absence of cd40 or cd40l, cd4(+) cells failed to get primed or produce ...200616622023
a young man who could not walk.infections affecting the central nervous system caused by blastomyces dermatitidis are rare but curable. we describe a case of a 24-year-old man who presented to the emergency department with progressive bilateral lower extremity weakness over 1 month. on the day of admission, he had minimal muscle strength and was hyperreflexic in the lower extremities. sensation, however, was intact. skin examination revealed annular, raised, crusted lesions on his face and legs. a magnetic resonance imaging ( ...200616676493
it's on the tip of my tongue.a 48-year-old white woman was admitted to the hospital with low-grade fever, night sweats, fatigue, nonproductive cough with dyspnea, bilateral knee pain, and swelling that progressed slowly over 6 weeks. she was a 30-pack-year smoker, and had received outpatient antibiotic therapy with clarithromycin and then cephalexin without improvement. the admission chest radiograph showed bilateral interstitial infiltrates, and an effusion was seen on knee radiographs. she was treated with levofloxacin, c ...200616687984
disseminated blastomycosis in an infant.blastomycosis is an uncommon life-threatening disease caused by the dimorphic fungus blastomyces dermatitidis. estimates of the percentage of cases occurring in children range from 2% to 11%, and it is exceedingly rare in individuals less than 1 year of age. we present the case of an otherwise healthy infant with disseminated blastomycosis acquired in northern ontario and a brief review of the pediatric literature.200616804444
analysis of non-adhesive pathogenic mechanisms of bad1 on blastomyces dermatitidis.the adhesin bad1 is required for virulence of blastomyces dermatitidis in a pulmonary model of infection. herein, we explored mechanisms by which bad1 enhances pathogenicity of the fungus. isogenic strains with and without bad1 exhibited similar phenotypic differences in virulence by pulmonary and intravenous routes of infection, indicating that bad1 may exert virulence beyond adherence to respiratory lining cells. non-adhesive mechanisms including maintenance of intrinsic resistance of yeast ag ...200616805092
susceptibility to pulmonary blastomycosis in young compared to adult mice: immune deficiencies in young mice.the immunological basis for differences in resistance to pulmonary blastomycosis between young (3 to 4-week-old) and adult (7 to 8-week-old) cd-1 mice is unknown. we assessed whether there were differences in fungicidal activity of phagocytes and th-1 lymphocyte cytokine production. the fungicidal activity of young bronchoalveolar macrophages (bam) (20%) against blastomyces dermatitidis (bd) was comparable to killing by adult bam (25%). however, ifn-gamma enhanced the killing by adult bam (from ...200616805093
[three cases of cutaneous blastomycosis].blastomycosis is a rare mycotic infection in africa. isolated cutaneous disease is extremely rare. we report three cases of cutaneous blastomycosis confirmed by istologic and mycologic examination. no visceral involvement was found. blastomycosis is rare in tunisia. the most common site of involvement is the lung. the three cases reported presented with skin involvement only, suggesting a cutaneous inoculation of blastomyces dermatitidis. the diagnostic criteria of cutaneous blastomycosis are di ...200616809013
clinical aspects of natural infection with blastomyces dermatitidis in cats: 8 cases (1991-2005).to evaluate clinical and laboratory findings, treatment, and clinical outcome in cats with blastomycosis.200616817721
blastomycosis presenting as recurrent tender cutaneous nodules.blastomycosis is caused by inhalation of airborne spores from blastomyces dermatitidis, a dimorphic fungus found in soil. it is endemic in the southeastern, midwestern, and south central states of north america. the clinical spectrum of blastomycosis is varied, including asymptomatic infection, acute or chronic pneumonia, and disseminated disease. definitive diagnosis is based on identification of the characteristic thick-walled, broad-based budding yeasts by direct examination of tissue or the ...200616821476
detection of igg and igm in sera from canines with blastomycosis using eight blastomyces dermatitidis yeast phase lysate antigens.the objective of this study was to compare the efficacy of eight blastomyces dermatitidis yeast phase lysate antigens (t-58: dog, tennessee; t-27: polar bear, tennessee; erc-2: dog, wisconsin; b5894: human, minnesota; soil: soil, canada; b5896: human, minnesota; 48089: human, zaire; 48938: bat, india) in the detection of the immunoglobulins igg and igm in serum specimens from canines with blastomycosis. an indirect enzyme-linked immunosorbent assay (elisa, peroxidase system) was used to analyze ...200616830189
effect of lung surfactant collectins on bronchoalveolar macrophage interaction with blastomyces dermatitidis: inhibition of tumor necrosis factor alpha production by surfactant protein d.alveolar surfactant modulates the antimicrobial function of bronchoalveolar macrophages (bam). little is known about the effect of surfactant-associated proteins in bronchoalveolar lavage fluid (balf) on the interaction of bam and blastomyces dermatitidis. we investigated balf enhancement or inhibition of tnf-alpha production by bam stimulated by b. dermatitidis. bam from cd-1 mice were stimulated with b. dermatitidis without or with normal balf, surfactant protein a-deficient (sp-a-/-) or surfa ...200616861641
identification of histoplasma capsulatum, blastomyces dermatitidis, and coccidioides species by repetitive-sequence-based pcr.the performance of repetitive-sequence-based pcr (rep-pcr) using the diversilab system for identification of coccidioides species, blastomyces dermatitidis, and histoplasma capsulatum was assessed by comparing data obtained to colony morphology and microscopic characteristics and to nucleic acid probe results. dna from cultures of 23 coccidioides, 24 b. dermatitidis, 24 h. capsulatum, 3 arthrographis, and 2 malbranchea isolates was extracted using a microbial dna isolation kit as recommended by ...200616891521
how to diagnose and treat fungal infections in chronic prostatitis.epidemiologic changes that include immune-compromised patients and drug-resistant fungi have caused an increase in nosocomial infections by candida albicans and non-albicans candida species. other fungi, aspergilla and cryptococcus (environmental contaminants), are opportunistic invaders of the immune-compromised (transplant, hiv) patients. the environmental fungi coccidioides immitis (dry arid areas), histoplasma capsulatum (avian-infested areas), and blastomyces dermatitidis (aquatic areas) ca ...200616930504
mixed pulmonary infection with strongyloides stercoralis and blastomyces dermatitidis.we report the first case of mixed pulmonary infection with strongyloides stercoralis and blastomyces dermatitidis. histopathology from the lung biopsy showed structures consistent with b. dermatitidis and s. stercoralis. a parasitology exam from a bronchi alveolar lavage yielded an immature rhabditiform larva and female worm. fungal cultures grew b. dermatitidis.200616957042
human and canine pulmonary blastomycosis, north carolina, 2001-2002.we investigated a cluster of blastomycosis in 8 humans and 4 dogs in a rural north carolina community. delayed diagnosis, difficulty isolating blastomyces dermatitidis in nature, and lack of a sensitive and specific test to assess exposure make outbreaks of this disease difficult to study.200616965704
blastomycosis in a south indian patient after visiting an endemic area in usa.we describe a case of blastomycosis in a diabetic patient from south india who had visited milwaukee, wisconsin, an endemic area for blastomycosis in the usa. after his return to bangalore, india, the patient developed intermittent fever of moderate to high grade, cough, loss of weight and appetite, and abscesses in the left cubital fossa and thigh regions. systemic examination at our hospital revealed that he had dullness to percussion over the chest region and decreased breath sounds. direct e ...200616966169
v beta1+ j beta1.1+/v alpha2+ j alpha49+ cd4+ t cells mediate resistance against infection with blastomyces dermatitidis.immunization with a cell wall/membrane (cw/m) and yeast cytosol extract (yce) crude antigen from blastomyces dermatitidis confers t-cell-mediated resistance against lethal experimental infection in mice. we isolated and characterized t cells that recognize components of these protective antigens and mediate protection. cd4+ t-cell clones elicited with cw/m antigen adoptively transferred protective immunity when they expressed a v alpha2+ j alpha49+/v beta1+ j beta1.1+ heterodimeric t-cell recept ...200717030569
blastomyces dermatitidis of the perianal skin: report of a case.isolated fungal infections of the perianal skin are rare and their diagnosis is frequently overlooked. we report a case of a 78-year-old male patient who presented with a friable, violaceous, papulopustular lesion, with heaped-up edges along the anal verge. biopsy revealed unicellular yeast consistent with blastomycosis. the patient was treated with itraconazole with resolution of this lesion. an extensive medline literature review from 1958 to the present indicates that this is an uncommon mani ...200717082893
blastomycosis in solid organ transplant recipients.blastomyces dermatitidis, the etiologic agent of blastomycosis, causes severe disease and substantial mortality in those immunocompromised by acquired immunodeficiency syndrome or malignancy. in solid organ transplant recipients, the epidemiology, clinical features, and outcomes have not been fully described.200717428278
blastomyces dermatitidis osteomyelitis of the tibia. 200717460873
development and application of a green fluorescent protein sentinel system for identification of rna interference in blastomyces dermatitidis illuminates the role of septin in morphogenesis and sporulation.a high-throughput strategy for testing gene function would accelerate progress in our understanding of disease pathogenesis for the dimorphic fungus blastomyces dermatitidis, whose genome is being completed. we developed a green fluorescent protein (gfp) sentinel system of gene silencing to rapidly study genes of unknown function. using gateway technology to efficiently generate rna interference plasmids, we cloned a target gene, "x," next to gfp to create one hairpin to knock down the expressio ...200717496124
typing of histoplasma capsulatum strains by fatty acid profile analysis.the performance of fatty acid profiling for strain differentiation of histoplasma capsulatum was assessed. total fatty acids were isolated from the yeast-phase cells of seven stock and two previously unreported clinical strains of h. capsulatum var. capsulatum, as well as from one unreported clinical strain and one stock strain of h. capsulatum var. duboisii, and one strain of each of three other dimorphic zoopathogenic fungal species, blastomyces dermatitidis, paracoccidioides brasiliensis and ...200717510264
isoelectric focusing and elisa evaluation of a blastomyces dermatitidis human isolate.blastomyces dermatitidis is a dimorphic fungal organism and the causative agent of blastomycosis. this organism is endemic east of the mississippi river as is the fungal organism histoplasma capsulatum. this study was performed to determine if sensitive and specific antigens from the b. dermatitidis yeast phase lysate (human isolate 592) could be separated using isoelectric focusing (ief) to eliminate antigens that are cross-reactive with h. capsulatum. indirect enzyme linked immunosorbent assay ...200717578679
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