BackgroundThere have been several recent changes in the taxonomy of Sporothrix schenckii as well as new observations regarding the clinical aspects of sporotrichosis. In this study, we determined the identification of the Sporothrix species associated with both classic and unusual clinical aspects of sporotrichosis observed in the endemic area of sporotrichosis in Rio de Janeiro, Brazil.Methodology/Principal FindingsTo verify whether S. brasiliensis is associated with clinical manifestations of sporotrichosis, a cross-sectional study was performed in which Sporothrix isolates from 50 patients with different clinical manifestations were analyzed and their isolates were studied by phenotypic and genotypic methods. Data from these patients revealed a distinct clinical picture and therapeutic response in infections caused by Sporothrix brasiliensis (n = 45) compared to patients with S. schenckii sensu stricto (n = 5). S. brasiliensis was associated with disseminated cutaneous infection without underlying disease, hypersensitivity reactions, and mucosal infection, whereas patients with S. schenckii presented with less severe and more often localized disease, similar to the majority of previously described sporotrichosis cases. Interestingly, S. brasiliensis-infected patients overall required shorter durations of itraconazole (median 16 weeks) compared to the individuals with S. schenckii (median 24 weeks).Conclusions/SignificanceThese findings suggest that Sporothrix species are linked to different clinical manifestations of sporotrichosis and that S. brasiliensis is effectively treated with oral itraconazole.
Sporotrichosis has significantly increased in Brazil in the last decade, particularly in the state of Rio de Janeiro, with the occurrence of an epidemic related to zoonotic transmission from cats to humans. Recently, four new phylogenetic species were incorporated into the Sporothrix species complex based on the phenotypic and molecular characteristics, and a new species name (Sporothrix brasiliensis) was proposed for some of the Sporothrix isolates from this epidemic. This study describes the characterization of 246 isolates obtained from patients attending the Laboratory of Infectious Dermatology, IPEC-FIOCRUZ, between 1998 and 2008, together with one environmental sample. Two hundred and six of the isolates (83.4%) were characterized as S. brasiliensis, 15 (6.0%) as S. schenckii, and one (0.5%) as S. mexicana. Twenty-five isolates (10.1%) could not be identified according to their phenotype and were classified as Sporothrix spp. The calmodulin gene was sequenced to confirm the identity of these isolates. The molecular analysis demonstrated that 24 of the isolates were S. brasiliensis, with the remainder being a S. globosa isolate. The isolate characterized phenotypically as S. mexicana was clustered on the S. schenckii clade. The correlation between molecular data and phenotypic characteristics described in this study is fundamental to the identification of the Sporothrix complex.
Sporotrichosis is endemic in Rio de Janeiro, Brazil, and cases have been reported to be associated with HIV. This article describes the clinical manifestations and evolution of sporotrichosis in HIV-positive patients and constitutes the largest case series reported to date. There were 21 HIV-positive patients with sporotrichosis diagnosed by the recovery of the etiologic agent from 1999-2009. Sixteen patients (76.2%) were men and five (23.8%) were women, with a mean age of 41.2 years. Seven of these individuals were previously unaware of their HIV infection. Mean CD4 count was 346.4 cells/μl. The most frequent clinical presentations of sporotrichosis in these patients were the lymphocutaneous and disseminated form (seven patients each, 33.3%), followed by the widespread cutaneous form in five (23.8%), and fixed form in the remaining two (9.5%). In patients with the disseminated forms, clinical manifestations involved the skin in six, mucosa (nasal, oral, or conjunctival) in four, bone in two, and meninges in two. Eleven (52.4%) patients received itraconazole and eight (38.1%) amphotericin B contributing to an overall cure rate of 81%. Spontaneous cure was observed in one patient. The clinical forms of sporotrichosis varied according to the patients' immune status. The results demonstrate the importance of sporotrichosis as an opportunistic infection associated with AIDS in countries where the mycosis occurs.
Clinical and Laboratory Standards Institute (CLSI) conditions for testing the susceptibilities of pathogenic species to antifungal agents are based on a collaborative study that evaluated five clinically relevant isolates of and some antifungal agents. With the advent of molecular identification, there are two basic needs: to confirm the suitability of these testing conditions for all agents and species and to establish species-specific epidemiologic cutoff values (ECVs) or breakpoints (BPs) for the species. We collected available CLSI MICs/minimal effective concentrations (MECs) of amphotericin B, five triazoles, terbinafine, flucytosine, and caspofungin for 301, 486 , 75, and 13 molecularly identified isolates. Data were obtained in 17 independent laboratories (Australia, Europe, India, South Africa, and South and North America) using conidial inoculum suspensions and 48 to 72 h of incubation at 35°C. Sufficient and suitable data (modal MICs within 2-fold concentrations) allowed the proposal of the following ECVs for and , respectively: amphotericin B, 4 and 4 μg/ml; itraconazole, 2 and 2 μg/ml; posaconazole, 2 and 2 μg/ml; and voriconazole, 64 and 32 μg/ml. Ketoconazole and terbinafine ECVs for were 2 and 0.12 μg/ml, respectively. Insufficient or unsuitable data precluded the calculation of ketoconazole and terbinafine (or any other antifungal agent) ECVs for , as well as ECVs for and These ECVs could aid the clinician in identifying potentially resistant isolates (non-wild type) less likely to respond to therapy.
BACKGROUNDSporotrichosis is caused by species of the genus Sporothrix. From 1998 to 2015, 4,703 cats were diagnosed at the Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil. Even after the description of the Sporothrix species, the characterisation of feline isolates is not performed routinely.OBJECTIVESTo characterise the clinical isolates from cats at the species level and correlate them with the clinical and epidemiological characteristics of the cats.METHODSForty seven Sporothrix spp. isolates from cats assisted at Fiocruz from 2010 to 2011 were included. Medical records were consulted to obtain the clinical and epidemiological data. The isolates were identified through their morphological and physiological characteristics. T3B polymerase chain reaction (PCR) fingerprinting was used for molecular identification of the species.FINDINGSIn phenotypic tests, 34 isolates were characterised as S. brasiliensis, one as S. schenckii and 12 as Sporothrix spp. PCR identified all isolates as S. brasiliensis.MAIN CONCLUSIONS S. brasiliensis is the only etiological agent of feline sporotrichosis in Rio de Janeiro to date. None association was found between the isolates and the clinical and epidemiological data. In addition, we strongly recommend the use of molecular techniques for the identification of isolates of Sporothrix spp.
Sporothrix schenckii is the etiological agent of sporotrichosis, the main subcutaneous mycosis in Latin America. Melanin is an important virulence factor of S. schenckii, which produces dihydroxynaphthalene melanin (DHN-melanin) in conidia and yeast cells. Additionally, L-dihydroxyphenylalanine (L-DOPA) can be used to enhance melanin production on these structures as well as on hyphae. Some fungi are able to synthesize another type of melanoid pigment, called pyomelanin, as a result of tyrosine catabolism. Since there is no information about tyrosine catabolism in Sporothrix spp., we cultured 73 strains, including representatives of newly described Sporothrix species of medical interest, such as S. brasiliensis, S. schenckii, and S. globosa, in minimal medium with tyrosine. All strains but one were able to produce a melanoid pigment with a negative charge in this culture medium after 9 days of incubation. An S. schenckii DHN-melanin mutant strain also produced pigment in the presence of tyrosine. Further analysis showed that pigment production occurs in both the filamentous and yeast phases, and pigment accumulates in supernatants during stationary-phase growth. Notably, sulcotrione inhibits pigment production. Melanin ghosts of wild-type and DHN mutant strains obtained when the fungus was cultured with tyrosine were similar to melanin ghosts yielded in the absence of the precursor, indicating that this melanin does not polymerize on the fungal cell wall. However, pyomelanin-producing fungal cells were more resistant to nitrogen-derived oxidants and to UV light. In conclusion, at least three species of the Sporothrix complex are able to produce pyomelanin in the presence of tyrosine, and this pigment might be involved in virulence. Melanins are polymers with diverse molecular structures, typically black or dark brown, formed by the oxidative polymerization of phenolic and indolic compounds. They are produced by a broad range of organisms, from bacteria to humans. Several fungi can produce melanins, and the functions of these pigments are related to microbial survival under several unfavorable environmental and host conditions (10, 14). The major melanin type encountered among fungi is 1,8-dihydroxynaphthalene melanin (DHN-melanin), which is synthesized from acetyl coenzyme A via the polyketide pathway. This form of melanin is synthesized by several plant and human fungal pathogens. In addition to DHN-melanin, certain fungi can also produce melanin via dihydroxyphenylalanine (DOPA), in which tyrosinases or laccases hydroxylate tyrosine via DOPA to dopaquinone, which then auto-oxidizes and polymerizes, resulting in a polyphenolic heteropolymer that is black (9). Some fungi produce a soluble melanin from L-tyrosine through p-hydroxyphenylpyruvate and homogentisic acid. This soluble pigment is called pyomelanin, and it is similar to the alkaptomelanin produced by humans. Aspergillus fumigatus, Madurella mycetomatis, and Yarrowia lipolytica are examples of fungi that can produce this type of soluble pigment (4,18,20)...
The Sporothrix complex members cause sporotrichosis, a subcutaneous mycosis with a wide spectrum of clinical manifestations. Several specific phenotypic characteristics are associated with virulence in many fungi, but studies in this field involving the Sporothrix complex species are scarce. Melanization, thermotolerance, and production of proteases, catalase, and urease were investigated in 61 S. brasiliensis, one S. globosa, and 10 S. schenckii strains. The S. brasiliensis strains showed a higher expression of melanin and urease compared with S. schenckii. These two species, however, presented similar thermotolerances. Our S. globosa strain had low expression of all studied virulence factors. The relationship between these phenotypes and clinical aspects of sporotrichosis was also evaluated. Strains isolated from patients with spontaneous regression of infection were heavily melanized and produced high urease levels. Melanin was also related to dissemination of internal organs and protease production was associated with HIV-coinfection. A murine sporotrichosis model showed that a S. brasiliensis strain with high expression of virulence factors was able to disseminate and yield a high fungal burden in comparison with a control S. schenckii strain. Our results show that virulence-related phenotypes are variably expressed within the Sporothrix complex species and might be involved in clinical aspects of sporotrichosis.
Introduction The agents of paracoccidioidomycosis, historically identified as Paracoccidioides brasiliensis , are in fact different phylogenetic species. This study aims to evaluate associations between Paracoccidioides phylogenetic species and corresponding clinical data. Methods Paracoccidioides strains from INI/Fiocruz patients (1998–2016) were recovered. Socio-demographic, epidemiological, clinical, serological, therapeutic and prognostic data of the patients were collected to evaluate possible associations of these variables with the fungal species identified through partial sequencing of the ADP-ribosylation factor ( arf ) and the 43-kDa-glycoprotein ( gp43 ) genes. Results Fifty-four fungal strains were recovered from 47 patients, most (72.3%) infected in Rio de Janeiro state, Brazil. Forty-one cases were caused by Paracoccidioides brasiliensis and six by Paracoccidioides americana (former PS2). P . brasiliensis was responsible for severe lymph abdominal forms, whereas patients infected with P . americana presented a high rate of adrenal involvement. However, no statistically significant associations were found for all variables studied. P . americana presented 100% reactivity to immunodiffusion, even when tested against antigens from other species, while negative results were observed in 9 (20%) cases caused by P . brasiliensis , despite being tested against a homologous antigen. Conclusions P . brasiliensis and P . americana are sympatric and share similar clinical features and habitat, where they may compete for similar hosts.
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