Primary cutaneous fungal infections in solid organ transplantation: a case series.
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Cutaneous fungal infections in solid-organ transplant patients present in a variety of nonspecific ways, requiring a high index of suspicion to diagnose correctly. In the present series of four transplant recipients, subsequent primary cutaneous fungal infections presented as papules, plaques, ulcers and subcutaneous nodules. Transplantations included one cardiac, two renal and one renal-pancreatic transplant. Fungal infections were limited to the skin; there was no evidence of disseminated disease in any case. The pathogens isolated were Scedosporium apiospermum (Pseudallescheria boydii), Alternaria species, Aspergillus fumigatus, and a coelomycete in the Coniothyrium-Microsphaeropsis complex of dark molds. Individuals were successfully treated with surgical debridement, antifungal agents, and reduction of immunosuppressive therapy. All patients and allografts survived. Accurate diagnosis, aggressive surgery and appropriate antifungal therapy, combined with close outpatient follow-up, optimize the likelihood of a cure in a transplant population. (+info)
Primary cutaneous cryptococcosis due to Cryptococcus neoformans var. gattii serotype B, in an immunocompetent patient.
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The authors report a male patient, a seller with no detected immunosuppression, with an extensive ulcerated skin lesion localized on the left forearm, caused by Cryptococcus neoformans var. gattii serotype B. Oral treatment with fluconazole was successful. A review of the literature showed the rarity of this localization in HIV-negative patients. In contrast, skin lesions frequently occurs in HIV-positive patients, with Cryptococcus neoformans var. neoformans serotype A predominating as the etiological agent. In this paper, the pathogenicity of C. neoformans to skin lesions in patients immunocompromised or not, is discussed, showing the efficacy of fluconazole for the treatment of these processes. (+info)
Secreted metalloprotease gene family of Microsporum canis.
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Keratinolytic proteases secreted by dermatophytes are likely to be virulence-related factors. Microsporum canis, the main agent of dermatophytosis in dogs and cats, causes a zoonosis that is frequently reported. Using Aspergillus fumigatus metalloprotease genomic sequence (MEP) as a probe, three genes (MEP1, MEP2, and MEP3) were isolated from an M. canis genomic library. They presented a quite-high percentage of identity with both A. fumigatus MEP and Aspergillus oryzae neutral protease I genes. At the amino acid level, they all contained an HEXXH consensus sequence, confirming that these M. canis genes (MEP genes) encode a zinc-containing metalloprotease gene family. Furthermore, MEP3 was found to be the gene encoding a previously isolated M. canis 43.5-kDa keratinolytic metalloprotease, and was successfully expressed as an active recombinant enzyme in Pichia pastoris. Reverse transcriptase nested PCR performed on total RNA extracted from the hair of M. canis-infected guinea pigs showed that at least MEP2 and MEP3 are produced during the infection process. This is the first report describing the isolation of a gene family encoding potential virulence-related factors in dermatophytes. (+info)
An isolate of Arthroderma benhamiae with Trichophyton mentagrophytes var. erinacei anamorph isolated from a four-toed hedgehog (Atelerix albiventris) in Japan.
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A female four-toed hedgehog probably imported from Africa and kept as a pet by a family suffered from depilation and mite (Caparinia tripilis) infection. Depilated quills were inoculated on a commercially available medium and an isolate of the dermatophytes was obtained. A giant colony after 14 days incubation on yeast extract Sabourauds agar had a central umbo with white granular surface and a yellow pigment ring in the reverse. The hedgehog isolate produced numerous elongated microconidia singly attached along the sides of hyphae. Macroconidia were somewhat irregular in shape and size and 2-6 septa. Abundant intermediate sized spores between micro- and macro conidia and few spirals were observed. Hair perforation and urease activity tests were positive. Maximum growth temperature was 40 C. In the mating tests using the tester strains of both African and Americano-European races of Arthroderma benhamiae, the strain produced numerous gymnothecia only when paired with the African race mating type minus(-). In addition, 591 bases of the internal transcribed spacer region of the ribosomal RNA gene including the 5.8S region (ITS1-5.8S-ITS2) were sequenced and corresponded to those of T. mentagrophytes var. erinacei (DDBJ/EMBL/GenBank accession numbers Z97996 and Z97997) by more than 99.7%. Therefore, our case is the first isolation of A. benhamiae with T. mentagrophytes var. erinacei anamorph in Japan. (+info)
Isolation of a Microsporum canis gene family encoding three subtilisin-like proteases expressed in vivo.
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Microsporum canis is the main agent of dermatophytosis in dogs and cats and is responsible for frequent zoonosis. The pathogenesis of the disease remains largely unknown, however. Among potential fungal virulence factors are secreted keratinolytic proteases, whose molecular characterization would be an important step towards the understanding of dermatophytic infection pathogenesis. M. canis secretes a 31.5 kDa keratinolytic subtilisin-like protease as the major component in a culture medium containing cat keratin as the sole nitrogen source. Using a probe corresponding to a gene's internal fragment, which was obtained by polymerase chain reaction, the entire gene encoding this protease named SUB3 was cloned from a M. canislambdaEMBL3 genomic library. Two closely related genes, termed SUB1 and SUB2, were also cloned from the library using as a probe the gene coding for Aspergillus fumigatus 33 kDa alkaline protease (ALP). Deduced amino acid sequence analysis revealed that SUB1, SUB2, and SUB3 are secreted proteases and show large regions of identity between themselves and with subtilisin-like proteases of other filamentous fungi. Interest ingly, mRNA of SUB1, SUB2, and SUB3 were detected by reverse transcriptase nested-polymerase chain reaction from hair of experimentally infected guinea pigs. These results show that SUB1, SUB2, and SUB3 encode a family of subtilisin-like proteases and strongly suggest that these proteases are produced by M. canis during the invasion of keratinized structures. This is the first report describing the isolation of a gene family encoding potential virulence-related factors in dermatophytes. (+info)
A unique isolate of Malassezia from a cat.
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An isolate of Malassezia from a cat with otitis externa was examined mycologically as well as molecularly. The isolate was similar to M. sympodialis in morphological and biochemical characteristics. In molecular analysis, however, it differed from the 7 species of Malassezia previously reported. Therefore, this clinical isolate from a cat might be a new species of Malassezia. (+info)
Evaluation of the effect of pH on in vitro growth of Malassezia pachydermatis.
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The purpose of this study was to evaluate the effects of pH on the growth of canine Malassezia pachydermatis isolates in vitro. Yeast growth was monitored by measuring the optical density with a spectrophotometer. The growth of American Type Culture Collection and field strains of M. pachydermatis was optimal between the pH values of 4.0 and 8.0, and inhibited at the ranges of 1.0 to 3.0 and 9.0 to 10.0. An analysis of covariance showed no significant differences among the growth curves at pH levels 5.0 to 8.0. Although specific contrast tests showed that the growth slope at pH 4.0 was significantly different from that at pH 5.0 to 8.0, only small, random differences were found when the growth slope at pH 4.0 was compared to the individual slopes at pH 5.0, 6.0, 7.0, and 8.0. The findings of this study suggest that topical acidifying products could be beneficial therapeutic options for cutaneous yeast infections in dogs. (+info)
Dermatophyte infections.
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Dermatophytes are fungi that require keratin for growth. These fungi can cause superficial infections of the skin, hair, and nails. Dermatophytes are spread by direct contact from other people (anthropophilic organisms), animals (zoophilic organisms), and soil (geophilic organisms), as well as indirectly from fomites. Dermatophyte infections can be readily diagnosed based on the history, physical examination, and potassium hydroxide (KOH) microscopy. Diagnosis occasionally requires Wood's lamp examination and fungal culture or histologic examination. Topical therapy is used for most dermatophyte infections. Cure rates are higher and treatment courses are shorter with topical fungicidal allylamines than with fungistatic azoles. Oral therapy is preferred for tinea capitis, tinea barbae, and onychomycosis. Orally administered griseofulvin remains the standard treatment for tinea capitis. Topical treatment of onychomycosis with ciclopirox nail lacquer has a low cure rate. For onychomycosis, "pulse" oral therapy with the newer imidazoles (itraconazole or fluconazole) or allylamines (terbinafine) is considerably less expensive than continuous treatment but has a somewhat lower mycologic cure rate. The diagnosis of onychomycosis should be confirmed by KOH microscopy, culture, or histologic examination before therapy is initiated, because of the expense, duration, and potential adverse effects of treatment. (+info)