Deep fungal infections in tropical countries

Mycetoma: a clinical dilemma in resource limited settings

Background

Mycetoma is a chronic mutilating disease of the skin and the underlying tissues caused by fungi or bacteria. Although recently included in the list of neglected tropical diseases by the World Health Organization, strategic control and preventive measures are yet to be outlined. Thus, it continues to pose huge public health threat in many tropical and sub-tropical countries. If not detected and managed early, it results into gruesome deformity of the limbs. Its low report and lack of familiarity may predispose patients to misdiagnosis and delayed treatment initiation. More so in situation where diagnostic tools are limited or unavailable, little or no option is left but to clinically diagnose these patients. Therefore, an overview of clinical course of mycetoma, a suggested diagnostic algorithm and proposed use of materials that cover the exposed susceptible parts of the body during labour may assist in the prevention and improvement of its management. Furthermore, early reporting which should be encouraged through formal and informal education and sensitization is strongly suggested.

Main text

An overview of the clinical presentation of mycetoma in the early and late phases, clues to distinguish eumycetoma from actinomycetoma in the field and the laboratory, differential diagnosis and a suggested diagnostic algorithm that may be useful in making diagnosis amidst the differential diagnosis of mycetoma is given. Additionally, a proposed preventive measures which may be helpful in the community is also provided. Since treatment is currently based on expert opinion, we encourage active research to establish treatment guideline for it.

Conclusion

Since delay in visiting health facility results into gruesome complication, early presentation, recognition and initiation of appropriate choice of regimen is helpful in reducing complications. The clinical overview of mycetoma and the suggested algorithm may enhance suspicion and possibly increase recognition of mycetoma in the community and further guide in differentiation of eumycetoma from actinomycetoma. There is an urgent need for research funding for mycetoma, a disease plagued by severe physical disabilities and social stigma leading to isolation.

Electronic supplementary material

The online version of this article (10.1186/s12941-018-0287-4) contains supplementary material, which is available to authorized users.

Sporothrix schenckii Immunization, but Not Infection, Induces Protective Th17 Responses Mediated by Circulating Memory CD4+ T Cells

Sporotrichosis is a chronic subcutaneous mycosis caused by the Sporothrix schenckii species complex and it is considered an emerging opportunistic infection in countries with tropical and subtropical climates. The host’s immune response has a main role in the development of this disease. However, it is unknown the features of the memory cellular immune response that could protect against the infection. Our results show that i.d. immunization in the ears of mice with inactivated S. schenckii conidia (iC) combined with the cholera toxin (CT) induces a cellular immune response mediated by circulating memory CD4⁺ T cells, which mainly produce interleukin 17 (IL-17). These cells mediate a strong delayed-type hypersensitivity (DTH) reaction. Systemic and local protection against S. schenckii was mediated by circulating CD4⁺ T cells. In contrast, the infection induces a potent immune response in the skin mediated by CD4⁺ T cells, which have an effector phenotype that preferentially produce interferon gamma (IFN-γ) and mediate a transitory DTH reaction. Our findings prove the potential value of the CT as a potent skin adjuvant when combined with fungal antigens, and they also have important implications for our better understanding of the differences between the memory immune response induced by the skin immunization and those induced by the infection; this knowledge enhances our understanding of how a protective immune response against a S. schenckii infection is developed.

Analysis of Paracoccidioides lutzii mitochondria: a proteomic approach

The genus Paracoccidioides is composed of thermal dimorphic fungi, causative agents of paracoccidioidomycosis, one of the most frequent systemic mycoses in Latin America. Mitochondria have sophisticated machinery for ATP production, which involves metabolic pathways such as citric acid and glyoxylate cycles, electron transport chain and oxidative phosphorylation. In addition, this organelle performs a variety of functions in the cell, working as an exceptional metabolic signalling centre that contributes to cellular stress responses, as autophagy and apoptosis in eukaryotic organisms. The aim of this work was to perform a descriptive proteomic analysis of mitochondria in Paracoccidioides lutzii yeast cells. After mitochondria fractionation, samples enriched in mitochondrial proteins were digested with trypsin and analysed using a NanoUPLC-MS^E system (Waters Corporation, Manchester, UK). Ours results revealed that the established protocol for purification of mitochondria was very effective for P. lutzii, and 298 proteins were identified as primarily mitochondrial, in our analysis. To our knowledge, this is the first compilation of mitochondrial proteins from P. lutzii, to date. Copyright © 2016 John Wiley & Sons, Ltd.

Case report: Sporotrichosis from the Northern Territory of Australia

We report three cases of lymphocutaneous infection caused by the thermally dimorphic fungus, Sporothrix schenckii from Australia's tropical Northern Territory. Two cases were acquired locally, making them the first to be reported from this region. All three cases presented with ulceration in the limb; however, the classical sporotrichoid spread was present only in the first two cases. Their occurrence within several weeks of each other was suggestive of a common source of environmental contamination such as hay used as garden mulch. Diagnoses were delayed in each case, with each patient having substantial exposure to ineffective antibiotics before the correct diagnosis was made. These cases bring the total number of reported sporotrichosis cases in Australia since 1951 to 199. Lessons from these cases are to consider the diagnosis of sporotrichosis in lesions of typical appearance, even in geographical settings from where this pathogen has not previously been reported.

Cell wall proteins of Sporothrix schenckii as immunoprotective agents

Sporothrix schenckii is the etiological agent of sporotrichosis, an endemic subcutaneous mycosis in Latin America. Cell wall (CW) proteins located on the cell surface are inducers of cellular and humoral immune responses, potential candidates for diagnosis purposes and to generate vaccines to prevent fungal infections. This mini-review emphasizes the potential use of S. schenckii CW proteins as protective and therapeutic immune response inducers against sporotrichosis. A number of pathogenic fungi display CW components that have been characterized as inducers of protective cellular and humoral immune responses against the whole pathogen from which they were originally purified. The isolation and characterization of immunodominant protein components of the CW of S. schenckii have become relevant because of their potential in the development of protective and therapeutic immune responses against sporotrichosis. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012).

Isolation of Sporothrix schenckii from the claws of domestic cats (indoor and outdoor) and in captivity in São Paulo (Brazil)

Sporotrichosis is a subcutaneous mycosis and is also a zoonosis (sapro- and anthropozoonosis). The objective of the present study was to determine the occurrence of sporotrichosis in domestic cats and in wild or exotic felines in captivity through the isolation of Sporothrix spp. from claw impressions in a culture medium. The samples included 132 felines, of which 120 (91.0 %) were domestic cats, 11 (8.3 %) were wild felines, and one (0.7 %) was an exotic felid. Twenty-one (17.5 %) were outdoor cats. Of the total, 89 (67.4 %) had contact with other animals of the same species. It was possible to isolate Sporothrix schenckii from the claws of one (0.7 %) of the felids probed; this animal exhibited generalised sporotrichosis and had infected a female veterinarian. The potential pathogenic agents Microsporum canis and Malassezia pachydermatis were isolated in 12.1 and 5.3 % of the animals, respectively. The following anemophilous fungi, which were considered to be contaminants, were also isolated: Penicillium sp. (28 or 21.2 %), Aspergillus sp. (13 or 9.8 %), Rhodotorula sp. (5 or 3.8 %), Candida sp. (5 or 3.8 %), Trichoderma sp. (1 or 0.7 %), and Acremonium sp. (1 or 0.7 %). Due to the low magnitude of occurrence (0.7 %) of Sporothrix in feline claws, the potential of the cats evaluated in this study to be sources of infection in the city of São Paulo is considerably low.

Cutaneous sporotrichosis: a six-year review of 19 cases in a tertiary referral center in Malaysia

BACKGROUND

Sporotrichosis is a subcutaneous fungal infection caused by a thermally dimorphic aerobic fungus, Sporothrix schenckii. It results from traumatic inoculation or contact with animals. Most cases were reported mainly in the tropics and subtropics.

OBJECTIVE

  The objective of our study is to assess the clinical characteristic of cutaneous sporotrichosis among our patients.

METHODOLOGY

We performed a retrospective review of all cases diagnosed with cutaneous sporotrichosis from July 2004 to June 2010. Patients' medical records were retrieved and analyzed according to demography, preceding trauma, sites of lesions, clinical subtypes, treatment, and clinical response.

RESULTS

Nineteen cases were diagnosed with cutaneous sporotrichosis with a male/female ratio of 9:10. Thirteen cases (68.4%) were able to recall preceding trauma, and seven of them reported cat scratches or cat bites. Lymphocutaneous sporotrichosis was observed in 13 cases (68.4%) followed by four cases of fixed cutaneous sporotrichosis and two cases of disseminated sporotrichosis. Histologically, 11 cases (57.8%) demonstrated a granulomatous reaction. Sporothrix schenckii was cultured in 12 cases (63.2%). Thirteen cases (68.4%) were successfully treated with oral itraconazole alone for a mean duration of 15.6 weeks. Two cases with disseminated cutaneous sporotrichosis were treated with intravenous amphotericin B.

CONCLUSION

  Lymphocutaneous sporotrichosis was the most common subtype of cutaneous sporotrichosis in our series, with cat scratches or bites being the most common preceding trauma. Oral itraconazole was highly effective for the localized subtypes, whereas intravenous amphotericin B was required in disseminated cutaneous sporotrichosis.

Thoracic paracoccidioidomycosis: radiographic and CT findings

Paracoccidioidomycosis (PCM) is the most common systemic mycosis in Latin America. Although most cases occur in developing countries, recent immigration patterns and an increase in travel have led to a growing number of PCM cases in the United States and Europe. PCM is caused by the dimorphic fungus Paracoccidioides brasiliensis, and the chronic form may progress to severe pulmonary involvement. Several radiologic patterns have been described for pulmonary PCM, including linear and reticular opacities, variable-sized nodules, patchy ill-defined opacities, airspace consolidation, and cavitary lesions. Fibrosis and paracicatricial emphysema are common associated findings. Chest computed tomography (CT) is the method of choice for evaluating pulmonary PCM, with the most common CT findings being ground-glass attenuation, consolidation, small or large nodules, masses, cavitations, interlobular septal thickening, emphysema, and fibrotic lesions. PCM is also an important cause of the "reversed halo" sign at high-resolution CT and should be considered in the differential diagnosis. Awareness of the multiple radiologic manifestations of PCM as well as its epidemiologic and clinical characteristics may permit early diagnosis and initiation of specific treatment, thereby reducing associated morbidity and mortality.

Chromoblastomycosis: study of 27 cases and review of medical literature

BACKGROUND

Chromoblastomycosis is a subcutaneous mycosis that occurs mainly in rural workers although is being more commonly found among people working in other sectors. The fungus penetrates the skin after its inoculation and the most frequently isolated agent is the Fonsecaea pedrosoi.

OBJECTIVES

This study aims at evaluating patients suffering from chromoblastomycosis admitted into the Department of Dermatology of the University Hospital of the Faculty of Medicine of São Paulo State during the ten-year period from 1997 to 2007.

METHODS

It is a retrospective study and the medical report cards of 27 Brazilian patients diagnosed as suffering from Chromoblastomycosis from 1997 to 2007 at the Dermatology Department of the Medical School, University of Sao Paulo were reviewed. The following items were analyzed: previous therapeutic approaches; treatment implemented by the group; length of time between the appearing of the lesion and diagnosis; age; gender; profession; origin; site of lesions; isolated agents found in culture and histopathology.

RESULTS

Twenty two patients were from the state of Sao Paulo whereas the others came from the states of Bahia and Rondonia. 37% of them were rural workers. Men were more frequently infected (85%). Lesions were more commonly found on the lower limbs (59.2%). In 52% of the cases the isolated agent was the dematiaceous fungus Fonsecaea. pedrosoi. Biopsies showed sclerotic bodies in 92.5% of the cases.

CONCLUSION

Data found are in accordance with medical literature on the subject. The disease had been previously studied in our institution in 1983 by Cucé et al. This present study is the second retrospective one about the characteristics of patients suffering from chromoblastmycosis which has been published in indexed medical literature in the state of Sao Paulo.

Cell wall glycoproteins participate in the adhesion of Sporothrix schenckii to epithelial cells

Sporothrix schenckii is the etiologic agent of sporotrichosis. This fungal infection is an emerging disease potentially fatal in immunocompromised patients. The adhesion to host cells is a crucial early event related with the dissemination of pathogens. In order to clarify the mechanisms of adhesion of S. schenckii yeast cell to epithelial cells, we studied the biochemical basis of this process. The electrophoretic analysis of cell wall protein from S. schenckii coupled at ConA and stained with HRP, revealed nine different proteins with MW ≥ 180, 115, 90, 80, 58, 40, 36, 22 and 18 kDa. Using ligand-like assay with biotinylated S. schenckii surface proteins, five proteins with MW ≥ 190, 180, 115, 90 and 80 kDa which have affinity to epithelial cells were identified. The adhesion of yeast to epithelial monolayer was significantly inhibited when S. schenckii was pretreated with concanavalinA (ConA) and wheat germ agglutinin (WGA) lectins, alkali, periodate, trypsin, endoglycosidase H (EndoH), salt solutions and detergents. The ability of adhesion of S. schenckii yeast was recovered by blocking the lectin with sugar complementary. These data suggest that surface glycoprotein with mannose and glucose residue could be participate in the process of fungal adhesion to epithelial cells.

Sporotrichosis: a retrospective evaluation of 23 cases seen in northern California (1987-2007)

Sporotrichosis is an uncommon to rare cutaneous and subcutaneous mycosis of animals and humans caused by the dimorphic fungus Sporothrix schenckii. Twenty-three mammalian cases of sporotrichosis examined between 1987 and 2007 at the University of California, Davis - Veterinary Medical Teaching Hospital, were retrospectively evaluated with regard to the historical, clinical, diagnostic and treatment findings. Cats were the most common species affected (n = 14). In addition, sporotrichosis was diagnosed in four dogs, four horses and a donkey. Six of 23 cases were diagnosed with the localized cutaneous form of sporotrichosis (four cats, one dog, one horse), 10 with the cutaneous-lymphatic form (four cats, two dogs, three horses and a donkey), and seven with the disseminated form (six cats, one dog). Two of 23 cases did not have skin lesions at the time of diagnosis (one cat, one dog). The most common mode of diagnosis was demonstration of S. schenckii on histopathological evaluation of tissue. In contrast with most previously described sporotrichosis infections in cats, few to no fungal organisms were seen in histopathological samples (haematoxylin and eosin and special stains) in five of the 14 cats. Treatments received included itraconazole (12 cats, one dog), ketoconazole (three dogs), fluconazole (one cat, one donkey), sodium iodide (four horses, one cat) and potassium iodide (one cat, one horse, one donkey). The prognosis for successful treatment was good in all species. Fluconazole was successful in inducing resolution of the cutaneous lesions and controlling the infection in one cat with disseminated sporotrichosis.

Current research on the immune response to experimental sporotrichosis

Sporotrichosis is often manifested as a chronic granulomatous infection and the monocytes/macrophages play a central role in the host defense system. Surface components of Sporothrix schenckii have been characterized and suggestions have been made as to their possible role in pathogenicity. Ergosterol peroxide, cell-wall compounds (alkali-insoluble fraction-F1 and lipid extract-LEY), and exoantigen from the yeast form of the fungus have been characterized as virulence factors, activating both innate, by cytotoxins linked to the activation of reactive oxygen and nitrogen species (H2O2 and NO), and adaptive immune response to produce cytokines Th1 and Th2 profile. In this study, preliminary results have demonstrated that, in systemic sporotrichosis, TLR-4 triggers the innate immune response, activating an oxidative burst. These data represent the first report of the participation of TLR-4 in murine sporotrichosis, in the presence of lipids from the cell wall of S. schenckii. These results taken together may open new perspectives of study leading to an antifungal agent that could be used to benefit the entire population.

Passive immunization with monoclonal antibody against a 70-kDa putative adhesin of Sporothrix schenckii induces protection in murine sporotrichosis

Cell-mediated and innate immunity are considered the most important mechanisms of host defense against fungus infections. However, recent studies demonstrated that specific antibodies show different degrees of protection against mycosis. In a previous study, antigens secreted by Sporothrix schenckii induced a specific humoral response in infected animals, mainly against the 70-kDa molecule, indicating a possible participation of antibodies to this antigen in infection control. In the present study, an IgG1 mAb was produced against a 70-kDa glycoprotein of S. schenckii in order to better understand the effect of passive immunization of mice infected with S. schenckii. Results showed a significant reduction in the number of CFU in organs of mice when the mAb was injected before and during S. schenckii infection. Similar results were observed when T-cell-deficient mice were used. Moreover, in a second schedule treatment, the mAb was injected after infection was established, and again we observed a significant reduction in CFU associated with an increase of IFN-gammaproduction. Also, the 70-kDa antigen is shown to be a putative adhesin present on the surface of this fungus. In conclusion, we report for the first time the protective effect of a specific antibody against S. schenckii.

Imported tropical infectious ulcers in travelers

Skin ulcers are a commonly encountered problem at departments of tropical dermatology in the Western world. Furthermore, the general dermatologist is likely to be consulted more often for imported chronic skin ulcers because of the ever-increasing travel to and from tropical countries. The most common cause of chronic ulceration throughout the world is probably pyoderma. However, in some parts of the world, cutaneous leishmaniasis is one of the most prevalent causes. Mycobacterium ulcerans is an important cause of chronic ulcers in West Africa. Bacterial infections include pyoderma, mycobacterial infections, diphtheria, and anthrax. Pyoderma is caused by Staphylococcus aureus and/or beta-hemolytic streptococci group A. This condition is a common cause of ulcerative skin lesions in tropical countries and is often encountered as a secondary infection in travelers. The diagnosis is often made on clinical grounds. Antibacterial treatment for pyoderma should preferably be based on culture outcome. Floxacillin is generally active against S. aureus and beta-hemolytic streptococci. Infection with Mycobacterium ulcerans, M. marinum, and M. tuberculosis may cause ulcers. Buruli ulcers, which are caused by M. ulcerans, are endemic in foci in West Africa and have been reported as an imported disease in the Western world. Treatment is generally surgical, although a combination of rifampin (rifampicin) and streptomycin may be effective in the early stage. M. marinum causes occasional ulcerating lesions in humans. Treatment regimens consist of combinations containing clarithromycin, rifampin, or ethambutol. Cutaneous tuberculosis is rare in travelers but may be encountered in immigrants from developing countries. Treatment is with multiple drug regimens consisting of isoniazid, ethambutol, pyrazinamide, and rifampin. Cutaneous diphtheria is still endemic in many tropical countries. Cutaneous diphtheria ulcers are nonspecific and erythromycin and penicillin are both effective antibacterials. Antitoxin should be administered intramuscularly in suspected cases. Anthrax is caused by spore-forming Bacillus anthracis. This infection is still endemic in many tropical countries. Eschar formation, which sloughs and leaves behind a shallow ulcer at the site of inoculation, characterizes cutaneous anthrax. Penicillin and doxycycline are effective antibacterials. Cutaneous leishmaniasis is caused by different species belonging to the genus Leishmania. The disorder is one of the ten most frequent causes of skin diseases in travelers returning from (sub)tropical countries. The clinical picture is diverse, ranging from a painless papule or nodule to an ulcer with or without a scab. Treatment depends on the clinical manifestations and the species involved.Sporotrichosis, chromo(blasto)mycosis, and mycetoma are the most common mycoses that may be accompanied by ulceration. Infections are restricted to certain regions and often result from direct penetration of the fungus into the skin. Anti-mycotic treatment depends on the microorganism involved. The most common causes of infectious skin ulceration encountered in patients from tropical countries who present at a department of tropical dermatology are reviewed in this article.

Sporotrichosis: success of itraconazole treatment

An 82-year-old man with hypothyroidism presented with an ulcerated nodule on the dorsum of his left hand (Figure 1). The lesion had been present for about 3 months. Similar lesions were present along the lymphatic distribution of the dorsum of his left forearm, proximal to the first lesion, as well as the dorsum of his right forearm. Laboratory findings were normal. Immune complexes, complement 3, and complement 4 were negative. A biopsy from an ulcerated nodule was taken for both histologic examination and culture. Hematoxylin and eosin sections showed a nonspecific chronic granulomatous reaction. No fungi were detected by periodic acid-Schiff stain and methenamine silver stain. Culture of tissue obtained from a skin biopsy of 1 lesion placed directly on Sabouraud agar produced colonies of Sporothrix schenckii (Figure 2). The diagnosis of lymphocutaneous sporotrichosis was confirmed.

Cytokines released from blood monocytes and expressed in mucocutaneous lesions of patients with paracoccidioidomycosis evaluated before and during trimethoprim-sulfamethoxazole treatment

BACKGROUND

Mucocutaneous lesions in paracoccidioidomycosis are granulomatous and result from tissue responses to Paracoccidioides brasiliensis, the aetiological agent.

OBJECTIVES AND METHODS

In this study we investigate the expression of tumour necrosis factor (TNF)-alpha, interleukin (IL)-10 and transforming growth factor (TGF)-beta1 by immunohistochemistry in skin and mucosa lesions from patients with the chronic form of paracoccidioidomycosis, evaluated before and at day 20 of trimethoprim-sulfamethoxazole treatment. Cytokine production by peripheral blood monocytes was also studied by enzyme immunoassay.

RESULTS

Intense immunostaining for TNF-alpha was detected in mononuclear cells that infiltrated granulomas in all skin and mucosa lesions before treatment simultaneously with low IL-10 granular deposits in these cells. At day 20 of treatment, there was reduced TNF-alpha and IL-10 deposition. Immunoreactive TGF-beta1 was observed diffusely in the dermis and generally in the cytoplasm of macrophages and giant cells, before treatment, and as increased TGF-beta1 deposits in the fibrosis area at day 20 of treatment. Peripheral blood monocytes from patients with paracoccidioidomycosis, evaluated before treatment, produced high endogenous levels of TNF-alpha, TGF-beta1 and IL-10 in relation to healthy controls. Lipopolysaccharide-stimulated monocytes from patients secreted lower levels of TNF-alpha in both periods of evaluation while no impairment in capacity of IL-10 and TGF-beta production was observed.

CONCLUSIONS

Trimethoprim-sulfamethoxazole therapy was effective in decreasing fungal load in the lesions, allowing patient immune response to control the infection leading to the healing of the lesions.

Immunofluorescence and flow cytometry analysis of fibronectin and laminin binding to Sporothrix schenckii yeast cells and conidia

The adherence of Sporothrix schenckii yeast cells to several extracellular matrix (ECM) components has already been demonstrated, but the mechanisms of these interactions remained to be defined. In indirect immunofluorescence assays with polyclonal antibodies directed towards the ECM proteins, both hyphae and yeast cells of S. schenckii exhibited the ability to bind laminin and fibronectin. Flow cytometry confirmed the binding of these proteins, and revealed a significant greater binding capability for the yeast cells than for the conidia. Fibronectin and laminin binding was dose-dependent and specific. In addition, competition experiments with synthetic peptides mimicking the adhesive sequences of these proteins, or with cell wall fractions and carbohydrates constitutive of their sugar chains, were performed in order to specify the peptide or carbohydrate motifs involved in the recognition process. A 50% reduction was noticed in fibronectin binding in the presence of the synthetic peptide RGD, and a 38% reduction in laminin binding with the peptide YIGSR. Some carbohydrate-containing fractions of the yeast cell wall also inhibited the binding of fibronectin, but had no significant effect on laminin binding. Together, these results suggest the presence at the yeast surface of distinct receptors for laminin and fibronectin.

Inhibitors of Civ1 kinase belonging to 6-aminoaromatic-2-cyclohexyldiamino purine series as potent anti-fungal compounds

There is today a blatant need for new antifungal agents, because of the recent increase in life-threatening infections involving an ever-greater number of fungal strains. Fungi make extensive use of kinases in the regulation of essential processes, in particular the cell cycle. Most fungal kinases, however, are shared with higher eukaryotes. Only the kinases which have no human homologs, such as the histidine kinases, can be used as targets for antifungal drugs design. This review describes efforts directed towards the discovery of drugs active against a novel target, the atypical cell cycle kinase, Civ1.

Differentiation of Fonsecaea pedrosoi mycelial forms into sclerotic cells is induced by platelet-activating factor

Platelet-activating factor (PAF) has been shown to induce the differentiation of several cell types. In this work, we evaluated the effects of PAF on the formation of sclerotic cells of Fonsecaea pedrosoi, the major causative agent of chromoblastomycosis. Cell differentiation was evaluated by light and electron microscopy, which showed that treatment of mycelial forms with PAF results in the generation of sclerotic bodies with typical morphological characteristics. Biochemical features of PAF-induced sclerotic cells were also analyzed and compared with those from sclerotic forms induced by propranolol, a previously described differentiating agent of F. pedrosoi. Chemical analyses of lipid and carbohydrate components from PAF- or propranolol-induced sclerotic bodies revealed that palmitic, stearic, oleic and linoleic acids were the major fatty acid components, while glucose, mannose, galactose and rhamnose were detected as the principal sugar constituents in these cells. Surface carbohydrate components of PAF- and propranolol-induced sclerotic cells were also evaluated, by flow cytometry analysis with twelve different lectins. The profile of reactivity of PAF- or propranolol-induced fungal cells with lectins was also very similar. Hydrolysis of the synthetic substrate p-nitrophenylphosphate by fungal cells demonstrated that the addition of PAF or propranolol to the mycelial cultures similarly promotes a significant increase in ecto-phosphatase activity. These results indicate that the differentiation of F. pedrosoi mycelial cells induced by PAF generates authentic sclerotic forms, as confirmed by the analysis of morphological and biochemical attributes. Since PAF is synthesized in normal conditions by the human host, these observations may have a correlation with the differentiation of F. pedrosoi in vivo.

Disseminated paracoccidioidomycosis: correlation between clinical and in vitro resistance to ketoconazole and trimethoprim sulphamethoxazole

The present study relates to a case of subacute multifocal paracoccidioidomycosis where the upper intestinal tract is involved. The involvement of the upper digestive tract is uncommon. The recommended therapeutic treatment plans and the difficulty in the treatment of paracoccidioidomycosis are discussed in association with susceptibility tests to antifungal drugs in vitro. This is the first report available in the literature showing, in parallel, clinical and in vitro resistance to ketoconazole and trimethoprim sulphamethoxazole, studied during the course of the disease.

Detection of Sporothrix schenckii in clinical samples by a nested PCR assay

Cutaneous sporotrichosis is a chronic granulomatous fungal infection caused by Sporothrix schenckii with worldwide distribution. Its traditional diagnosis is time-consuming and difficult to differentiate from that of a clinical sporotrichoid lesion caused by various pathogens. In this study, a nested PCR assay for the detection of S. schenckii was evaluated by using a sequence of 18S rRNA gene as a target. For the examination of specificity and sensitivity, five clinical isolates with 1 ATCC 10213 strain of S. schenckii, 10 strains of clinical common fungi, 3 strains of Mycobacterium spp., Staphylococcus aureus, and normal human skin tissue were used. The expected fragment was amplified from six S. schenckii isolates in the first round and nested PCR but not from other microorganisms and human DNA. Their sequences were 100% identical to the S. schenckii 18S rRNA gene sequence deposited in GenBank. A detection limit of 40 fg of S. schenckii DNA extract was determined with ethidium bromide staining. Serial dilution studies demonstrated that the nested PCR could detect a DNA amount of 1 CFU of S. schenckii in tissue samples. We further investigated the nested PCR assay for the detection of S. schenckii from the tail tissues of 5 experimentally infected mice and from the clinical biopsy specimens of 12 patients with sporotrichosis confirmed by culture or histochemical staining. The nested PCR assay was positive in all 5 infected mice and in 11 of the 12 clinical specimens. The high sensitivity and specificity of this nested PCR indicate that the assay can provide rapid diagnosis with sufficient accuracy to be clinically useful for patients with sporotrichosis.

In vitro comparison of activities of terbinafine and itraconazole against Paracoccidioides brasiliensis

In vitro, terbinafine is highly active against a broad spectrum of pathogenic fungi. We evaluated the activities of terbinafine and itraconazole against 31 isolates of Paracoccidioides brasiliensis. The tests were conducted by using a broth macrodilution procedure. MICs, in micrograms per milliliter, were as follows: terbinafine, 0.015 to 1.0 (geometric mean, 0.1188); itraconazole, 0.007 to 0.5 (geometric mean, 0.03165). The usual therapy for paracoccidioidomycosis is sulfonamides, amphotericin B, and azole derivatives (ketoconazole, itraconazole, and fluconazole). In comparison to amphotericin B, azole derivatives allow shorter treatment courses, can be administered orally, and are equally effective. Itraconazole has as high efficacy as ketoconazole, but with superior tolerance. It is the current drug of choice for treatment of paracoccidioidomycosis. The data obtained in this study indicate that terbinafine is active against P. brasiliensis in vitro and suggest that this allylamine can be considered a new option as drug therapy for paracoccidioidomycosis.

Sporotrichosis masquerading as pyoderma gangrenosum: case report and review of 19 cases of sporotrichosis

We present the case of a 59-year-old woman who had large ulcerations on her right leg that were diagnosed initially as pyoderma gangrenosum and treated with three immunosuppressive agents (cyclosporin, prednisone and azathioprine) for 6 months. Results of a biopsy at 6 months showed numerous cigar-shaped bodies consistent with Sporothrix schenckii; identification was confirmed by tissue culture. A retrospective review was performed for all cases diagnosed as sporotrichosis from tissue culture or biopsy specimens at the Mayo Clinic. Nineteen cases were identified. The present case was the only one in which fungal organisms were visible on histological examination. The present case emphasizes the importance of making a definitive histological diagnosis in unusual ulcer cases or in suspected cases of pyoderma gangrenosum before the initiation of immunosuppressive therapy. The large number of cigar-shaped bodies in the tissue is a rare finding in sporothrix infection and has been reported in only two cases previously.

New developments in chemotherapy for non-invasive fungal infections

Dermatomycosis and subcutaneous mycosis comprise the non-invasive fungal infections commonly encountered in clinical practice around the world. The limited activity of early topical antifungal agents prompted the development of more effective systemic agents. While griseofulvin has been used for more than four decades, the use of early azoles, such as ketoconazole have resulted in better patient compliance and thus greater success. However, poor response and recurrence in dermatomycosis, as well as toxicity associated with ketoconazole therapy, has led to the search for newer antifungal agents and more effective treatment strategies. Terbinafine, itraconazole and fluconazole have the advantage of non-toxicity and a broad spectrum of activity. An overview of non-invasive fungal infections, antifungal agents in clinical use and recent developments in antifungal therapy is reviewed in this article.