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1.
PLoS One ; 18(2): e0276508, 2023.
Article in English | MEDLINE | ID: mdl-36780451

ABSTRACT

Leprosy, also known as Hansen's, is one of the listed neglected tropical diseases as a major health problem global. Treatment is one of the main alternatives, however, the scarcity of medication and its poor distribution are important factors that have driven the spread of the disease, leading to irreversible and multi-resistant complications. This paper uses a distribution methodology to optimize medication administration, taking into account the most relevant attributes for the epidemiological profile of patients and the deficit in treatment via Polychemotherapy. Multi-criteria Decision Methods were applied based on AHP-Electre model in a database with information from patients in the state of Para between 2015 and 2020. The results pointed out that 84% of individuals did not receive any treatment and, among these, the method obtained a gain in the distribution of 68% in patients with positive diagnosis for leprosy.


Subject(s)
Leprosy , Humans , Pharmaceutical Preparations , Leprosy/drug therapy , Leprosy/epidemiology , Leprosy/diagnosis , Drug Therapy, Combination , Data Management , Databases, Factual
2.
Front Microbiol ; 11: 711, 2020.
Article in English | MEDLINE | ID: mdl-32477280

ABSTRACT

Human settlement of Madagascar traces back to the beginning of the first millennium with the arrival of Austronesians from Southeast Asia, followed by migrations from Africa and the Middle East. Remains of these different cultural, genetic, and linguistic legacies are still present in Madagascar and other islands of the Indian Ocean. The close relationship between human migration and the introduction and spread of infectious diseases, a well-documented phenomenon, is particularly evident for the causative agent of leprosy, Mycobacterium leprae. In this study, we used whole-genome sequencing (WGS) and molecular dating to characterize the genetic background and retrace the origin of the M. leprae strains circulating in Madagascar (n = 30) and the Comoros (n = 3), two islands where leprosy is still considered a public health problem and monitored as part of a drug resistance surveillance program. Most M. leprae strains (97%) from Madagascar and Comoros belonged to a new genotype as part of branch 1, closely related to single nucleotide polymorphism (SNP) type 1D, named 1D-Malagasy. Other strains belonged to the genotype 1A (3%). We sequenced 39 strains from nine other countries, which, together with previously published genomes, amounted to 242 genomes that were used for molecular dating. Specific SNP markers for the new 1D-Malagasy genotype were used to screen samples from 11 countries and revealed this genotype to be restricted to Madagascar, with the sole exception being a strain from Malawi. The overall analysis thus ruled out a possible introduction of leprosy by the Austronesian settlers and suggests a later origin from East Africa, the Middle East, or South Asia.

3.
Clin Biochem ; 66: 76-82, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30695682

ABSTRACT

OBJECTIVES: New user-friendly diagnostic tests for detection of individuals infected by Mycobacterium leprae (M. leprae), the causative pathogen of leprosy, can help guide therapeutic and prophylactic treatment, thus positively contributing to clinical outcome and reduction of transmission. To facilitate point-of-care testing without the presence of phlebotomists, the use of fingerstick blood (FSB) rather than whole blood-derived serum is preferred. This study is a first proof-of-principle validating that previously described rapid serum tests detecting antibodies and cytokines can also be used with FSB. METHODS: Quantitative detection of previously identified biomarkers for leprosy and M. leprae infection, anti-M. leprae PGL-I IgM antibodies (αPGL-I), IP-10 and CRP, was performed with lateral flow (LF) strips utilizing luminescent up-converting reporter particles (UCP) and a portable reader generating unbiased read-outs. Precise amounts of FSB samples were collected using disposable heparinized capillaries. Biomarker levels in paired FSB and serum samples were determined using UCP-LF test strips for leprosy patients and controls in Bangladesh, Brazil, South-Africa and the Netherlands. RESULTS: Correlations between serum and FSB from the same individuals for αPGL-I, CRP and IP-10 were highly significant (p < .0001) even after FSB samples had been frozen. The αPGL-I FSB test was able to correctly identify all multibacillary leprosy patients presenting a good quantitative correlation with the bacterial index. CONCLUSIONS: Reader-assisted, quantitative UCP-LF tests for the detection of humoral and cellular biomarkers for M. leprae infection, are compatible with FSB. This allows near-patient testing for M. leprae infection and immunomonitoring of treatment without highly trained staff. On site availability of test-result concedes immediate initiation of appropriate counselling and treatment. Alternatively, the UCP-LF format allows frozen storage of FSB samples compatible with deferred testing in central laboratories.


Subject(s)
Antibodies/blood , Blood Chemical Analysis/methods , C-Reactive Protein/analysis , Chemokine CXCL10/blood , Leprosy/diagnosis , Acrylic Resins/chemistry , Animals , Antibodies/immunology , Antigens, Bacterial/immunology , Biomarkers/blood , Blood Chemical Analysis/instrumentation , Female , Goats , Humans , Infrared Rays , Male , Mice , Mycobacterium leprae/immunology , Nanoparticles/chemistry , Nanoparticles/radiation effects , Point-of-Care Testing
4.
Sci Rep ; 8(1): 17920, 2018 12 18.
Article in English | MEDLINE | ID: mdl-30560920

ABSTRACT

Leprosy remains persistently endemic in several low- or middle income countries. Transmission is still ongoing as indicated by the unabated rate of leprosy new case detection, illustrating the insufficiency of current prevention methods. Therefore, low-complexity tools suitable for large scale screening efforts to specifically detect M. leprae infection and diagnose disease are required. Previously, we showed that combined detection of cellular and humoral markers, using field-friendly lateral flow assays (LFAs), increased diagnostic potential for detecting leprosy in Bangladesh compared to antibody serology alone. In the current study we assessed the diagnostic performance of similar LFAs in three other geographical settings in Asia, Africa and South-America with different leprosy endemicity. Levels of anti-PGL-I IgM antibody (humoral immunity), IP-10, CCL4 and CRP (cellular immunity) were measured in blood collected from leprosy patients, household contacts and healthy controls from each area. Combined detection of these biomarkers significantly improved the diagnostic potential, particularly for paucibacillary leprosy in all three regions, in line with data obtained in Bangladesh. These data hold promise for the use of low-complexity, multibiomarker LFAs as universal tools for more accurate detection of M. leprae infection and different phenotypes of clinical leprosy.


Subject(s)
Antibodies, Bacterial/blood , Antigens, Bacterial/immunology , Immunologic Tests/methods , Leprosy/diagnosis , Mycobacterium leprae/immunology , Adolescent , Adult , Aged , Brazil , C-Reactive Protein/metabolism , Case-Control Studies , Chemokine CCL4/blood , Chemokine CXCL10/blood , Child , China , Endemic Diseases , Ethiopia , Female , Humans , Immunity, Cellular , Immunity, Humoral , Leprosy/blood , Leprosy/immunology , Male , Middle Aged , Sensitivity and Specificity , Socioeconomic Factors , Young Adult
5.
Front Microbiol ; 9: 2211, 2018.
Article in English | MEDLINE | ID: mdl-30356683

ABSTRACT

The fungal genus Fonsecaea comprises etiological agents of human chromoblastomycosis, a chronic implantation skin disease. The current hypothesis is that patients acquire the infection through an injury from plant material. The present study aimed to evaluate a model of infection in plant and animal hosts to understand the parameters of trans-kingdom pathogenicity. Clinical strains of causative agents of chromoblastomycosis (Fonsecaea pedrosoi and Fonsecaea monophora) were compared with a strain of Fonsecaea erecta isolated from a living plant. The clinical strains of F. monophora and F. pedrosoi remained concentrated near the epidermis, whereas F. erecta colonized deeper plant tissues, resembling an endophytic behavior. In an invertebrate infection model with larvae of a beetle, Tenebrio molitor, F. erecta exhibited the lowest survival rates. However, F. pedrosoi produced dark, spherical to ovoidal cells that resembled muriform cells, the invasive form of human chromoblastomycosis confirming the role of muriform cells as a pathogenic adaptation in animal tissues. An immunologic assay in BALB/c mice demonstrated the high virulence of saprobic species in animal models was subsequently controlled via host higher immune response.

6.
PLoS Negl Trop Dis ; 12(6): e0006532, 2018 06.
Article in English | MEDLINE | ID: mdl-29953440

ABSTRACT

Mycobacterium leprae (M. leprae) is a human pathogen and the causative agent for leprosy, a chronic disease characterized by lesions of the skin and peripheral nerve damage. Zoonotic transmission of M. leprae to humans by nine-banded armadillos (Dasypus novemcinctus) has been shown to occur in the southern United States, mainly in Texas, Louisiana, and Florida. Nine-banded armadillos are also common in South America, and residents living in some areas in Brazil hunt and kill armadillos as a dietary source of protein. This study examines the extent of M. leprae infection in wild armadillos and whether these New World mammals may be a natural reservoir for leprosy transmission in Brazil, similar to the situation in the southern states of the U.S. The presence of the M. leprae-specific repetitive sequence RLEP was detected by PCR amplification in purified DNA extracted from armadillo spleen and liver tissue samples. A positive RLEP signal was confirmed in 62% of the armadillos (10/16), indicating high rates of infection with M. leprae. Immunohistochemistry of sections of infected armadillo spleens revealed mycobacterial DNA and cell wall constituents in situ detected by SYBR Gold and auramine/rhodamine staining techniques, respectively. The M. leprae-specific antigen, phenolic glycolipid I (PGL-I) was detected in spleen sections using a rabbit polyclonal antibody specific for PGL-I. Anti-PGL-I titers were assessed by ELISA in sera from 146 inhabitants of Belterra, a hyperendemic city located in western Pará state in Brazil. A positive anti-PGL-I titer is a known biomarker for M. leprae infection in both humans and armadillos. Individuals who consumed armadillo meat most frequently (more than once per month) showed a significantly higher anti-PGL-I titer than those who did not eat or ate less frequently than once per month. Armadillos infected with M. leprae represent a potential environmental reservoir. Consequently, people who hunt, kill, or process or eat armadillo meat are at a higher risk for infection with M. leprae from these animals.


Subject(s)
Antigens, Bacterial/immunology , Armadillos/microbiology , Disease Reservoirs/microbiology , Glycolipids/immunology , Leprosy/transmission , Meat/microbiology , Mycobacterium leprae/isolation & purification , Adult , Animals , Antigens, Bacterial/genetics , Antigens, Bacterial/isolation & purification , Brazil/epidemiology , Enzyme-Linked Immunosorbent Assay , Female , Glycolipids/genetics , Glycolipids/isolation & purification , Humans , Leprosy/epidemiology , Leprosy/microbiology , Male , Middle Aged , Mycobacterium leprae/genetics , Mycobacterium leprae/immunology , Polymerase Chain Reaction , Rabbits , Risk , Spleen/microbiology , Young Adult , Zoonoses
7.
Nat Commun ; 9(1): 352, 2018 01 24.
Article in English | MEDLINE | ID: mdl-29367657

ABSTRACT

Leprosy is a chronic human disease caused by the yet-uncultured pathogen Mycobacterium leprae. Although readily curable with multidrug therapy (MDT), over 200,000 new cases are still reported annually. Here, we obtain M. leprae genome sequences from DNA extracted directly from patients' skin biopsies using a customized protocol. Comparative and phylogenetic analysis of 154 genomes from 25 countries provides insight into evolution and antimicrobial resistance, uncovering lineages and phylogeographic trends, with the most ancestral strains linked to the Far East. In addition to known MDT-resistance mutations, we detect other mutations associated with antibiotic resistance, and retrace a potential stepwise emergence of extensive drug resistance in the pre-MDT era. Some of the previously undescribed mutations occur in genes that are apparently subject to positive selection, and two of these (ribD, fadD9) are restricted to drug-resistant strains. Finally, nonsense mutations in the nth excision repair gene are associated with greater sequence diversity and drug resistance.


Subject(s)
Anti-Infective Agents/pharmacology , Drug Resistance, Bacterial/genetics , Mycobacterium leprae/drug effects , Phylogeny , Codon, Nonsense , DNA, Bacterial/chemistry , Genome, Bacterial , Humans , Microbial Sensitivity Tests , Mycobacterium leprae/genetics , Mycobacterium leprae/isolation & purification
8.
s.l; s.n; 2018. 11 p. mapa, tab, graf.
Non-conventional in English | Sec. Est. Saúde SP, HANSEN, Hanseníase Leprosy, SESSP-ILSLPROD, Sec. Est. Saúde SP, SESSP-ILSLACERVO, Sec. Est. Saúde SP | ID: biblio-1095218

ABSTRACT

Leprosy is a chronic human disease caused by the yet-uncultured pathogen Mycobacterium leprae. Although readily curable with multidrug therapy (MDT), over 200,000 new cases are still reported annually. Here, we obtain M. leprae genome sequences from DNA extracted directly from patients' skin biopsies using a customized protocol. Comparative and phylogenetic analysis of 154 genomes from 25 countries provides insight into evolution and antimicrobial resistance, uncovering lineages and phylogeographic trends, with the most ancestral strains linked to the Far East. In addition to known MDT-resistance mutations, we detect other mutations associated with antibiotic resistance, and retrace a potential stepwise emergence of extensive drug resistance in the pre-MDT era. Some of the previously undescribed mutations occur in genes that are apparently subject to positive selection, and two of these (ribD, fadD9) are restricted to drug-resistant strains. Finally, nonsense mutations in the nth excision repair gene are associated with greater sequence diversity and drug resistance.


Subject(s)
Humans , Phylogeny , DNA, Bacterial/chemistry , Microbial Sensitivity Tests , Genome, Bacterial , Codon, Nonsense , Drug Resistance, Bacterial/genetics , Anti-Infective Agents/pharmacology , Mycobacterium leprae/isolation & purification , Mycobacterium leprae/drug effects , Mycobacterium leprae/genetics
9.
Sci Rep ; 7(1): 8868, 2017 08 21.
Article in English | MEDLINE | ID: mdl-28827673

ABSTRACT

Early detection of leprosy is key to reduce the ongoing transmission. Antibodies directed against M. leprae PGL-I represent a useful biomarker for detecting multibacillary (MB) patients. Since efficient leprosy diagnosis requires field-friendly test conditions, we evaluated two rapid lateral flow assays (LFA) for detection of Mycobacterium leprae-specific antibodies: the visual immunogold OnSite Leprosy Ab Rapid test [Gold-LFA] and the quantitative, luminescent up-converting phosphor anti-PGL-I test [UCP-LFA]. Test performance was assessed in independent cohorts originating from three endemic areas. In the Philippine cohort comprising patients with high bacillary indices (BI; average:4,9), 94%(n = 161) of MB patients were identified by UCP-LFA and 78%(n = 133) by Gold-LFA. In the Bangladeshi cohort, including mainly MB patients with low BI (average:1), 41%(n = 14) and 44%(n = 15) were detected by UCP-LFA and Gold-LFA, respectively. In the third cohort of schoolchildren from a leprosy hyperendemic region in Brazil, both tests detected 28%(n = 17) seropositivity. Both rapid tests corresponded well with BI(p < 0.0001), with a fairly higher sensitivity obtained with the UCP-LFA assay. However, due to the spectral character of leprosy, additional, cellular biomarkers are required to detect patients with low BIs. Therefore, the UCP-LFA platform, which allows multiplexing with differential biomarkers, offers more cutting-edge potential for diagnosis across the whole leprosy spectrum.


Subject(s)
Antibodies, Bacterial/immunology , Leprosy/diagnosis , Leprosy/immunology , Mycobacterium leprae/immunology , Point-of-Care Testing , Serologic Tests/methods , Antigens, Bacterial/immunology , Biomarkers , Brazil , Enzyme-Linked Immunosorbent Assay , Humans , ROC Curve
10.
PLoS Negl Trop Dis ; 10(11): e0005102, 2016 11.
Article in English | MEDLINE | ID: mdl-27893750

ABSTRACT

The human mutilating disease chromoblastomycosis is caused by melanized members of the order Chaetothyriales. To assess population diversity among 123 clinical strains of agents of the disease in Brazil we applied sequencing of the rDNA internal transcribed spacer region, and partial cell division cycle and ß-tubulin genes. Strains studied were limited to three clusters divided over the single family Herpotrichiellaceae known to comprise agents of the disease. A Fonsecaea cluster contained the most important agents, among which F. pedrosoi was prevalent with 80% of the total set of strains, followed by 13% for F. monophora, 3% for F. nubica, and a single isolate of F. pugnacius. Additional agents, among which two novel species, were located among members of the genus Rhinocladiella and Cyphellophora, with frequencies of 3% and 1%, respectively.


Subject(s)
Ascomycota/isolation & purification , Chromoblastomycosis/microbiology , Ascomycota/classification , Ascomycota/genetics , Brazil/epidemiology , Chromoblastomycosis/epidemiology , DNA, Fungal/genetics , DNA, Ribosomal Spacer/genetics , Humans , Molecular Epidemiology , Mycological Typing Techniques , Phylogeny
11.
PLOS Neglected tropical diseases ; 11(1): 1-5, 2016. ilus
Article in English | Sec. Est. Saúde SP, LILACS, SESSP-IALPROD, Sec. Est. Saúde SP, SESSP-IALACERVO | ID: biblio-1021882

ABSTRACT

The human mutilating disease chromoblastomycosis is caused by melanized members of the order Chaetothyriales. To assess population diversity among 123 clinical strains of agents of the disease in Brazil we applied sequencing of the rDNA internal transcribed spacer region, and partial cell division cycle and ß-tubulin genes. Strains studied were limited to three clusters divided over the single family Herpotrichiellaceae known to comprise agents of the disease. A Fonsecaea cluster contained the most important agents, among which F. pedrosoi was prevalent with 80% of the total set of strains, followed by 13% for F. monophora, 3% for F. nubica, and a single isolate of F. pugnacius. Additional agents, among which two novel species, were located among members of the genus Rhinocladiella and Cyphellophora, with frequencies of 3% and 1%, respectively.


Subject(s)
Humans , Disease , Chromoblastomycosis
12.
PLoS One ; 9(1): e85712, 2014.
Article in English | MEDLINE | ID: mdl-24465659

ABSTRACT

This study aims to assess the oxidative stress in leprosy patients under multidrug therapy (MDT; dapsone, clofazimine and rifampicin), evaluating the nitric oxide (NO) concentration, catalase (CAT) and superoxide dismutase (SOD) activities, glutathione (GSH) levels, total antioxidant capacity, lipid peroxidation, and methemoglobin formation. For this, we analyzed 23 leprosy patients and 20 healthy individuals from the Amazon region, Brazil, aged between 20 and 45 years. Blood sampling enabled the evaluation of leprosy patients prior to starting multidrug therapy (called MDT 0) and until the third month of multidrug therapy (MDT 3). With regard to dapsone (DDS) plasma levels, we showed that there was no statistical difference in drug plasma levels between multibacillary (0.518±0.029 µg/mL) and paucibacillary (0.662±0.123 µg/mL) patients. The methemoglobin levels and numbers of Heinz bodies were significantly enhanced after the third MDT-supervised dose, but this treatment did not significantly change the lipid peroxidation and NO levels in these leprosy patients. In addition, CAT activity was significantly reduced in MDT-treated leprosy patients, while GSH content was increased in these patients. However, SOD and Trolox equivalent antioxidant capacity levels were similar in patients with and without treatment. These data suggest that MDT can reduce the activity of some antioxidant enzyme and influence ROS accumulation, which may induce hematological changes, such as methemoglobinemia in patients with leprosy. We also explored some redox mechanisms associated with DDS and its main oxidative metabolite DDS-NHOH and we explored the possible binding of DDS to the active site of CYP2C19 with the aid of molecular modeling software.


Subject(s)
Clofazimine/therapeutic use , Dapsone/therapeutic use , Leprosy/drug therapy , Oxidative Stress/drug effects , Rifampin/therapeutic use , Adult , Analysis of Variance , Catalase/blood , Cytochrome P-450 CYP2C19/metabolism , Dapsone/blood , Dapsone/metabolism , Drug Therapy, Combination , Female , Glutathione/blood , Heinz Bodies/drug effects , Heinz Bodies/metabolism , Humans , Leprostatic Agents/therapeutic use , Leprosy/blood , Male , Methemoglobin/metabolism , Middle Aged , Oxidation-Reduction , Protein Binding , Reactive Oxygen Species/blood , Time Factors , Treatment Outcome , Young Adult
13.
BMC Res Notes ; 4: 24, 2011 Jan 28.
Article in English | MEDLINE | ID: mdl-21276247

ABSTRACT

BACKGROUND: Langerhans cells constitute a special subset of immature dendritic cells localized in the epidermis that play a key role in the skin's immune response. The production of cytokines is a key event in both the initiation and the regulation of immune responses, and different drugs can be used to remove or modify their production by DC and, therefore, alter immune responses in a broad spectrum of diseases, mainly in human inflammatory and autoimmune diseases. In the present study, we examined the effects of prednisone, thalidomide, cyclosporine A, and amitriptyline, drugs used in a variety of clinical conditions, on the production of TNF-α, IL-10, and IL-12 by purified epidermal Langerhans cells and peritoneal macrophages in BALB/c mice. FINDINGS: All drugs inhibited TNF-α production by Langerhans cells after 36 hours of treatment at two different concentrations, while prednisone and thalidomide decreased IL-12 secretion significantly, amitriptyline caused a less pronounced reduction and cyclosporine A had no effect. Additionally, TNF-α and IL-12 production by macrophages decreased, but IL-10 levels were unchanged after all treatments. CONCLUSIONS: Our results demonstrate that these drugs modulate the immune response by regulating pro-inflammatory cytokine production by purified epidermal Langerhans cells and peritoneal macrophages, indicating that these cells are important targets for immunosuppression in various clinical settings.

14.
BMC Infect Dis ; 10: 237, 2010 Aug 10.
Article in English | MEDLINE | ID: mdl-20698989

ABSTRACT

BACKGROUND: Mycobacterium leprae is the only pathogenic bacteria able to infect peripheral nerves. Neural impairment results in a set of sensitive, motor and autonomic disturbances, with ulcers originating primarily on the hands and feet. The study objectives were to analyze the clinic-epidemiological characteristics of patients attended at one specialized dressing service from a leprosy-endemic region of the Brazilian Amazon and to evaluate the effect of low level laser therapy (LLLT) on wound healing of these patients. METHODS: Clinic-epidemiological evaluation of patients with leprosy sequelae was performed at the reference unit in sanitary dermatology of the state of Pará in Brazil. We conducted anamnesis, identification of the regions affected by the lesions and measurement of ulcer depth and surface area. After that, we performed a randomized clinical trial. Fifty-one patients with ulcers related to leprosy were evaluated, twenty-five of them were randomly assigned to a low level laser therapy group or a control group. Patients were treated 3 times per week for 12 weeks. Outcome measures were ulcer surface area, ulcer depth and the pressure ulcer scale for healing score (PUSH). RESULTS: Ninety-seven ulcers were identified, with a mean (SD) duration of 97.6 (111.7) months, surface area of 7.3 (11.5) cm2, and depth of 6.0 (6.2) mm. Statistical analysis of the data determined that there were no significant differences in the variables analyzed before and after treatment with low level laser therapy. CONCLUSIONS: Ulcers in patients with leprosy remain a major source of economic and social losses, even many years after they have been cured of M. leprae infection. Our results indicate that it is necessary to develop new and more effective therapeutic tools, as low level laser therapy did not demonstrate any additional benefits to ulcer healing with the parameters used in this study. TRIAL REGISTRATION: The trial was registered at ClinicalTrials.gov as NCT00860717.


Subject(s)
Leprosy/complications , Leprosy/epidemiology , Low-Level Light Therapy/methods , Skin Ulcer/epidemiology , Skin Ulcer/therapy , Wound Healing/physiology , Adolescent , Adult , Aged , Aged, 80 and over , Brazil/epidemiology , Female , Humans , Leprosy/therapy , Male , Middle Aged , Skin Ulcer/pathology , Treatment Outcome , Young Adult
15.
J Cutan Pathol ; 36(2): 257-61, 2009 Feb.
Article in English | MEDLINE | ID: mdl-18727664

ABSTRACT

Chromoblastomycosis (CBM) is a difficult-to-treat dermal mycosis characterized by the presence of round, pigmented, sclerotic bodies formed by black fungi found in polymorphic lesions. According to the morphology of a lesion, different clinical types of the disease have been described. We present three patients who each developed a single, 10-cm diameter, 8 to 15-year-old, well-circumscribed, slow-growing, annular, papulosquamous or papulosquamous-verrucous lesion, with no regression despite the use of topical antifungals. Skin scrapings and biopsies confirmed CBM and microculture defined the agent as Fonsecaea pedrosoi. The patients were treated with 200 mg/day of itraconazole for 6-9 months and were discharged after complete regression of the lesions. All were examined after the first and second year of the end of treatment and there were no signs of recurrence. A new clinical type of CBM is described, and itraconazole appears to be effective and safe in curing these patients after no more than 9 months of therapy.


Subject(s)
Antifungal Agents/pharmacology , Ascomycota , Chromoblastomycosis , Itraconazole/pharmacology , Mitosporic Fungi , Administration, Cutaneous , Chromoblastomycosis/drug therapy , Chromoblastomycosis/microbiology , Chromoblastomycosis/pathology , Humans , Male , Middle Aged
16.
J Struct Biol ; 162(1): 75-84, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18096404

ABSTRACT

Melanin is a complex polymer widely distributed in nature and has been described as an important virulence factor in pathogenic fungi. In the majority of fungi, the mechanism of melanin formation remains unclear. In Fonsecaea pedrosoi, the major etiologic agent of chromoblastomycosis, melanin is stored in intracellular vesicles, named melanosomes. This paper details the ultrastructural aspects of melanin formation, its storage and transportation to the cell wall in the human pathogenic fungus F. pedrosoi. In this fungus, melanin synthesis within melanosomes also begins with a fibrillar matrix formation, displaying morphological and structural features similar to melanosomes from amphibian and mammalian cells. Silver precipitation based on Fontana-Masson technique for melanin detection and immunocytochemistry showed that melanosome fuses with fungal cell membrane where the melanin is released and reaches the cell wall. Melanin deposition in the fungal cell wall occurs in concentric layers. Antibodies raised against F. pedrosoi melanin revealed the sites of melanin production and storage in the melanosomes. In addition, a preliminary description of the elemental composition of this organelle by X-ray microanalysis and elemental mapping revealed the presence of calcium, phosphorus and iron concentrated in its matrix, suggesting a new functional role for these organelles as iron storage compartments.


Subject(s)
Ascomycota/ultrastructure , Melanosomes/ultrastructure , Ascomycota/metabolism , Electron Probe Microanalysis , Humans , Immunohistochemistry , Melanins/metabolism , Melanosomes/metabolism , Microscopy, Electron, Transmission , Mycoses/microbiology
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