RESUMO
Trichosporon spp. have recently emerged as significant human pathogens. Identification of these species is important, both for epidemiological purposes and for therapeutic management, but conventional identification based on biochemical traits is hindered by the lack of updates to the species databases provided by the different commercial systems. In this study, 93 strains, or isolates, belonging to 16 Trichosporon species were subjected to both molecular identification using IGS1 gene sequencing and matrix-assisted laser desorption ionisation-time-of-flight (MALDI-TOF) analysis. Our results confirmed the limits of biochemical systems for identifying Trichosporon species, because only 27 (36%) of the isolates were correctly identified using them. Different protein extraction procedures were evaluated, revealing that incubation for 30 min with 70% formic acid yields the spectra with the highest scores. Among the six different reference spectra databases that were tested, a specific one composed of 18 reference strains plus seven clinical isolates allowed the correct identification of 67 of the 68 clinical isolates (98.5%). Although until recently it has been less widely applied to the basidiomycetous fungi, MALDI-TOF appears to be a valuable tool for identifying clinical Trichosporon isolates at the species level.
Assuntos
Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Trichosporon/química , Trichosporon/classificação , Tricosporonose/diagnóstico , Tricosporonose/microbiologia , Proteínas Fúngicas/química , Proteínas Fúngicas/isolamento & purificação , Humanos , Sensibilidade e Especificidade , Manejo de Espécimes/métodos , Trichosporon/isolamento & purificaçãoRESUMO
The use of improved microbiological procedures associated with molecular techniques has increased the identification of Candida bloodstream infections, even if the isolation of more than one species by culture methods remains uncommon. We report the cases of two children presenting with severe gastrointestinal disorders and other risk factors that contribute to Candida infections. In the first patient, C. albicans DNA was initially detected by a nested-amplification and C. tropicalis was found later during hospitalization, while blood cultures were persistently negative. In the second child, there was amplification of C. albicans and C. glabrata DNA in the same samples, but blood cultures yielded only C. albicans. Both patients received antifungal therapy but had unfavorable outcomes. These two cases illustrate that PCR was more successful than culture methods in detecting Candida in the bloodstream of high risk children, and was also able to detect the presence of more than one species in the same patient that might impact therapy when the fungi are resistant to azole compounds.
Assuntos
Candidemia/diagnóstico , Micologia/métodos , Reação em Cadeia da Polimerase/métodos , Candida albicans/isolamento & purificação , Candida glabrata/isolamento & purificação , Candida tropicalis/isolamento & purificação , Candidemia/microbiologia , Criança , Pré-Escolar , Estado Terminal , Feminino , Gastroenteropatias/complicações , Humanos , MasculinoRESUMO
Since Paracoccidioides brasiliensis and Histoplasma capsulatum are known to be present in similar environments, there have been many epidemiologic investigations regarding the prevalences of these two organisms. However, cross-reactivity can occur in paracoccidioidin and histoplasmin skin tests, and this usually results in the overestimation of the prevalence of P. brasiliensis. The prevalence of infection with P. brasiliensis was evaluated in a cross-sectional study of 298 asymptomatic school children in the Brazilian Amazon region (Mato Grosso State). In this investigation, the reactivity of children to two different P. brasiliensis antigen preparations, paracoccidioidin and a purified 43-kD glycoprotein (gp43), was compared with or without the co-administration of histoplasmin. In the group of individuals receiving paracoccidioidin who had a positive histoplasmin skin test result, the prevalence of exposure to P. brasiliensis was 44% (16 of 36). This reactivity to P. brasiliensis was significantly higher than that observed in other groups, which ranged from 4% to 6% (P < 5 x 10(-4) for each). Overall prevalence was 4.6% (95% confidence interval = 2.5-7.7%). These data suggest that gp43 provides a better estimate of exposure to P. brasiliensis when the co-administration of histoplasmin is desired.
Assuntos
Antígenos de Fungos/análise , Proteínas Fúngicas , Glicosaminoglicanos/análise , Histoplasmina/análise , Paracoccidioides/imunologia , Paracoccidioidomicose/epidemiologia , Adolescente , Brasil/epidemiologia , Criança , Feminino , Proteínas Fúngicas/imunologia , Glicoproteínas/imunologia , Glicosaminoglicanos/imunologia , Histoplasmina/imunologia , Humanos , Testes Intradérmicos , Masculino , Paracoccidioidomicose/diagnóstico , Paracoccidioidomicose/imunologia , Prevalência , Testes CutâneosRESUMO
Forty-two patients with active paracoccidioidomycosis were randomized to receive itraconazole (50-100 mg d(-1)), ketoconazole (200-400 mg d(-1)) or sulfadiazine (100-150 mg kg d(-1) up to 6 g d(-1)) for 4-6 months, followed by slow release sulfa until negativity of serological tests. All 14 patients in itraconazole and sulfadiazine groups and 13 in the ketoconazole group showed an adequate clinical response to the chemotherapy. One patient in the latter group showed treatment failure according to clinical and mycological criteria. The test of the hypothesis that the drugs reduced antibody levels up to ten months of treatment showed a p value equal to 0.0001 for itraconazole, 0.017 for ketoconazole and 0.0012 for sulfadiazine; this reduction was similar for the three groups. In this first randomized study for the treatment of paracoccidioidomycosis we could not show superiority of any one regimen over the others in the clinical and serological responses of patients with the moderately severe form of the disease.
Assuntos
Antifúngicos/uso terapêutico , Paracoccidioidomicose/tratamento farmacológico , Adolescente , Adulto , Feminino , Humanos , Itraconazol/uso terapêutico , Cetoconazol/análogos & derivados , Cetoconazol/uso terapêutico , Masculino , Pessoa de Meia-Idade , Sulfadiazina/uso terapêutico , Resultado do TratamentoRESUMO
We investigated the relationship between antibody response to the major Paracoccidioides brasiliensis antigen, a 43-kDa glycoprotein, and the two paracoccidioidomycosis (PCM) clinical presentations, the juvenile and the adult forms. Total immunoglobulin G (IgG), IgG isotypes, and IgA anti-gp43 antibodies were determined by enzyme-linked immunosorbent assay in patients'sera. Juvenile PCM patients had higher (P =.003) IgG anti-gp43 levels than adult form patients. IgG1 subclass levels, however, were comparable between the two clinical forms. Patients with the juvenile form had higher (P <. 001) IgG4, but lower (P =.03) IgG2 levels than patients with the adult form. The IgG4 isotype, regulated by interleukin 4, was found in all juvenile form patients but in only 12% of the adult form patients. In contrast, high levels of the IgG2 isotype, regulated by interferon-gamma, were found in 41% of the adult PCM patients, mainly those with a more benign disease, but in only 12% of the juvenile patients. IgG3 was either absent or detected at low levels. These results demonstrate, for the first time, specific IgG4 antibodies in the humoral immune response of patients with an endemic deep mycosis and suggest that the switch to the IgG subclasses in PCM is regulated by the patients' T-helper subset (Th-1 or Th-2) dominant cytokine profile. A possible role for IgG4 in the immunopathogenesis of the juvenile, more severe form of the disease is discussed. Finally, IgA was found mainly in adult form patients, probably as a result of the chronic mucosal antigenic stimulation characteristic of this form.
Assuntos
Anticorpos Antifúngicos/sangue , Antígenos de Fungos , Proteínas Fúngicas , Glicoproteínas/imunologia , Isotipos de Imunoglobulinas/sangue , Oligossacarídeos/imunologia , Paracoccidioides/imunologia , Paracoccidioidomicose/imunologia , Adolescente , Adulto , Anticorpos Antifúngicos/imunologia , Criança , Contraimunoeletroforese , Citocinas/imunologia , Ensaio de Imunoadsorção Enzimática , Humanos , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Isotipos de Imunoglobulinas/imunologia , Células Th1/imunologia , Células Th2/imunologiaRESUMO
The authors conducted a mycologic, immunochemical and molecular biology study on two strains of Paracoccidioides brasiliensis, one of them, called IBIA, isolated from soil in the municipality of IBIA (Minas Gerais) by Silva-Vergara et al. (1996, 1998), and the other, BAT, cultivated from a human case of paracoccidioidomycosis in Ribeirão Preto (São Paulo/Brazil) by Freitas Da Silva (1996). Both strains showed cotton-like (M) and yeast-like (Y) forms and were pathogenic for testicularly inoculated guinea pigs, producing granulomatous and/or suppurative orchitis. Immunochemically was demonstrated the presence of gp43 by double immunodiffusion, immunoelectrophoresis and immunoblotting.
Assuntos
Paracoccidioides/classificação , Paracoccidioides/imunologia , Animais , Cobaias , Humanos , Imunoquímica/métodos , Técnicas de Tipagem Micológica , Paracoccidioides/isolamento & purificaçãoRESUMO
IgG, IgM and IgA antibodies to GP43 (glycoprotein fraction of Paracoccidioides brasiliensis) were measured by ELISA in 63 samples from 23 patients with paracoccidioidomycosis before and twice after chemotherapy was started. Antibodies against P. brasiliensis were detected by indirect immunofluorescence (IF) (IgG, IgM and IgA isotypes), counterimmunoelectrophoresis (CIE) and complement fixation. Two control groups composed of 19 healthy individuals and 12 patients with other diseases (six with histoplasmosis, three with tuberculosis and three with other mycoses). The highest efficiency percentages were found with IgG and IgA-ELISA (100%), IgG-IF (96.2%), CIE (94.4%) and the lowest with CF (75.9%). Highest positive and negative predictive values (100%) were observed for IgG and IgA ELISA. IgG and IgM-ELISA antibodies are more often found in patients with acute than chronic disease (P = 0.01). Four to six months after treatment follow-up showed decreased levels of IgG and IgM-ELISA for acute cases and decreased titres of CIE for chronic cases in relation to pretreatment levels. This study suggests that IgG-ELISA anti-GP43 represents a good marker to monitor clinical response to therapy.
Assuntos
Anticorpos Antifúngicos/sangue , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Paracoccidioidomicose/imunologia , Doença Aguda , Formação de Anticorpos , Antifúngicos/uso terapêutico , Doença Crônica , Testes de Fixação de Complemento , Contraimunoeletroforese , Ensaio de Imunoadsorção Enzimática , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Paracoccidioidomicose/sangue , Paracoccidioidomicose/tratamento farmacológico , Valores de ReferênciaRESUMO
UNLABELLED: Coccidioidomycosis is an endemic infection with a relatively limited geographic distribution: Mexico, Guatemala, Honduras, Colombia, Venezuela, Bolivia, Paraguay, Argentina and the southwest of the United States. In these countries, the endemic area is restricted to the semiarid desert like regions which are similar to the northeast of Brazil. CASE REPORT: The patient is a 32 year-old male, born in the state of Bahia (Northeast of Brazil) and has been living in São Paulo (Southeast) for 6 years. He was admitted at Hospital das Clínicas, at the Department of Pneumology in October 1996, with a 6 month history of progressive and productive cough, fever, malaise, chills, loss of weight, weakness and arthralgia in the small joints. Chest x-rays and computerized tomography disclosed an interstitial reticulonodular infiltrate with a cavity in the right upper lobe. The standard potassium hydroxide preparation of sputum and broncoalveolar lavage demonstrated the characteristic thickened wall spherules in various stages of development. Sabouraud dextrose agar, at 25 degrees C and 30 degrees C showed growth of white and cottony aerial miceleium. The microscopic morphology disclosed branched hyphae characterized by thick walled, barrel shaped arthroconidia alternated with empty cells. The sorological studies with positive double immunodiffusion test, and also positive complement fixation test in 1/128 dilution confirmed the diagnosis. The patient has been treated with ketoconazole and presents a favorable clinical and radiological evolution.
Assuntos
Coccidioidomicose/diagnóstico , Pneumopatias Fúngicas/diagnóstico , Adulto , Brasil , Humanos , MasculinoRESUMO
To characterize the immune dysfunction associated with paracoccidioidomycosis, we studied the in vitro lymphocyte reactivity to phytohemagglutinin (PHA), pokeweed mitogen (PWM), a Candida albicans antigen (CMA), and a Paracoccidioides brasiliensis antigen (PbAg) in 32 patients with the acute and the chronic form of the disease before or during the initial phase of treatment and after clinical cure. We also studied, as controls, 30 healthy individuals, 15 of them immune to P. brasiliensis. Results showed a strong hyporesponsiveness to the PbAg while responses to mitogens and CMA were comparable with those of controls. Patients with the acute form of the disease (usually more severe) had more marked PbAg hyporesponsiveness than those with the chronic form. After patients' clinical cure, PbAg proliferative responses were similar to controls and greater than those seen before pretreatment. Changes in other parameters were also seen in the treated patients; skin test anergy to paracoccidioidin, high levels of anti-P. brasiliensis antibodies, leukocytosis, and eosinophilia. These changes were usually more intense in patients with the acute form of the disease. The post-treatment CD4+, CD8+, and total lymphocyte counts were similar to those of controls. Correlation between these parameters and the lymphoproliferative responses to the various stimuli was only found with PbAg: PbAg responses correlated inversely with eosinophil and anti P. brasiliensis antibody levels. Overall, our results demonstrate an antigen-specific-cellular immunity defect, which is reversible with treatment and possibly related to a T helper cell-2 pattern of immune response during active disease.
Assuntos
Antígenos de Fungos/imunologia , Tolerância Imunológica , Paracoccidioidomicose/imunologia , Adolescente , Adulto , Anticorpos Antifúngicos/sangue , Criança , Humanos , Hipersensibilidade Tardia , Ativação Linfocitária , Pessoa de Meia-IdadeRESUMO
Sera from two patients with chronic active paracoccidioidomycosis yielded negative double immunodiffusion results with a culture filtrate antigen from Paracoccidioides brasiliensis routinely used in our laboratory. Complement fixation tests were positive for both sera using a polysaccharide-rich antigen. This study reports the results of a more extensive serological investigation of these two sera. Both a somatic antigen and a saline extract from the fungus yielded positive results in the double immunodiffusion. However, the immunodominant 43 kDa glycoprotein antigen showed negative results, although it was recognized by both sera in the Western blot assay. The value of the double immunodiffusion as a single serological test in paracoccidioidomycosis diagnosis is discussed.