91 research outputs found
A nodulo-cystic eumycetoma caused by Pyrenochaeta romeroi in a renal transplant recipient: A case report
<p>Abstract</p> <p>Introduction</p> <p><it>Pyrenochaeta romeroi </it>(<it>P. romeroi</it>) is a saprophytic fungus found in soil and plants. The fungal spores can be introduced into deeper tissues by trauma. It causes eumycetoma, which affects skin and subcutaneous tissues.</p> <p>Case presentation</p> <p>A 57-year-old South Asian man presented with a painless, nodular lesion (1 cm × 0.5 cm) on the left knee. He had had a renal transplant eight months earlier for end-stage renal failure. The patient was on tacrolimus, mycophenolate mofetil and prednisolone for immunosuppression. The lesion had progressed dramatically (to 5 cm × 5 cm) despite antibiotic treatment. The size and location of the lesion was severely affecting his quality of life, so an excision biopsy was performed. Nuclear ribosomal repeat-region sequencing confirmed the causative organism as <it>P. romeroi</it>. An <it>in vitro </it>antifungal susceptibility test demonstrated that <it>P. romeroi </it>was sensitive to voriconazole. Following a successful surgical removal, voriconazole was continued orally for two months.</p> <p>Conclusion</p> <p>To the best of our knowledge, we are reporting the first case of Eumycetoma caused by <it>P. romeroi </it>in a renal transplant recipient. Physicians should be aware of this rare fungal disease in transplant recipients. We recommend a combination of medical and surgical management in these immunosuppressed patients.</p
Subcutaneous Phaeohyphomycosis Cyst Associated with Medicopsis romeroi in an Immunocompromised Host
Cellular characterisation of Candida tropicalis presenting fluconazole-related trailing growth
Conidiation Color Mutants of Aspergillus fumigatus Are Highly Pathogenic to the Heterologous Insect Host Galleria mellonella
The greater wax moth Galleria mellonella has been widely used as
a heterologous host for a number of fungal pathogens including Candida
albicans and Cryptococcus neoformans. A positive
correlation in pathogenicity of these yeasts in this insect model and animal
models has been observed. However, very few studies have evaluated the
possibility of applying this heterologous insect model to investigate virulence
traits of the filamentous fungal pathogen Aspergillus
fumigatus, the leading cause of invasive aspergillosis. Here, we have
examined the impact of mutations in genes involved in melanin biosynthesis on
the pathogenicity of A. fumigatus in the G.
mellonella model. Melanization in A. fumigatus confers
bluish-grey color to conidia and is a known virulence factor in mammal models.
Surprisingly, conidial color mutants in B5233 background that have deletions in
the defined six-gene cluster required for DHN-melanin biosynthesis caused
enhanced insect mortality compared to the parent strain. To further examine and
confirm the relationship between melanization defects and enhanced virulence in
the wax moth model, we performed random insertional mutagenesis in the Af293
genetic background to isolate mutants producing altered conidia colors. Strains
producing conidia of previously identified colors and of novel colors were
isolated. Interestingly, these color mutants displayed a higher level of
pathogenicity in the insect model compared to the wild type. Although some of
the more virulent color mutants showed increased resistance to hydrogen
peroxide, overall phenotypic characterizations including secondary metabolite
production, metalloproteinase activity, and germination rate did not reveal a
general mechanism accountable for the enhanced virulence of these color mutants
observed in the insect model. Our observations indicate instead, that
exacerbated immune response of the wax moth induced by increased exposure of
PAMPs (pathogen-associated molecular patterns) may cause self-damage that
results in increased mortality of larvae infected with the color mutants. The
current study underscores the limitations of using this insect model for
inferring the pathogenic potential of A. fumigatus strains in
mammals, but also points to the importance of understanding the innate immunity
of the insect host in providing insights into the pathogenicity level of
different fungal strains in this model. Additionally, our observations that
melanization defective color mutants demonstrate increased virulence in the
insect wax moth, suggest the potential of using melanization defective mutants
of native insect fungal pathogens in the biological control of insect
populations
Therapy and prophylaxis of opportunistic infections in HIV-infected patients: a guideline by the German and Austrian AIDS societies (DAIG/ÖAG) (AWMF 055/066)
Intraoral Phaeohyphomycosis
Phaeohyphomycosis is an infection caused by pigment-producing saprophytic fungi. Systemic infections may occur in the immunocompromised patient. Infection in healthy individuals may result in subcutaneous abscess formation. Oral lesions appear to be rare. A case of intraoral phaeohyphomycosis presenting as a well-demarcated, painful nodule of the anterior hard palate in a 12-year-old healthy male is described. The mass was excised and the diagnosis was established following histopathologic examination of the tissue
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