Luciana Silva Guazzelli

Capítulo 7 - Zigomicose

Zygomycosis (mucormycosis) is a rare but highly invasive infection caused by fungi belonging to the order Mucorales, which includes the genera Rhizopus, Mucor, Rhizomucor, Absidia, Apophysomyces, Saksenaea, Cunninghamella, Cokeromyces and Syncephalastrum. This type of infection is usually associated with hematologic diseases, diabetic ketoacidosis and organ transplantation. The most common form of presentation is rhinocerebral mucormycosis, with or without pulmonary involvement. Pulmonary zygomycosis is more common in patients with profound, prolonged neutropenia and can present as segmental or lobar infiltrates, isolated nodules, cavitary lesions, hemorrhage or infarction. The clinical and radiological manifestations are often indistinguishable from those associated with invasive aspergillosis. This article describes the general characteristics of pulmonary zygomycosis, emphasizing laboratory diagnosis, and illustrates the morphology of some lesions.

Infección nosocomial por Trichosporon asahii: revisión clínica de 22 casos

Resumen Presentamos una serie de 22 casos de infeccion nosocomial por Trichosporon asahii , detectados en un periodo de seis anos (1999-2005). Los pacientes presentaron edades entre 6 y 72 anos, con un promedio de 47,3 anos y con leve predominio de hombres. Las enfermedades subyacentes, fueron insuficiencia respiratoria, cancer, diabetes, insuficiencia renal cronica, cirrosis y sida. Las condiciones predisponentes fueron antibioticoterapia, ventilacion mecanica, sonda vesical, cateter, corticoides, trasplantes, inmunosupresores, quimioterapia, granulocitopenia, procedimiento quirurgico y dialisis peritoneal ambulatoria continua. Los antifungicos mas utilizados fueron el fluconazol y la anfotericina B. Algunos pacientes recibieron varios antifungicos. Cinco pacientes no fueron tratados con antifungicos y un paciente recibio factor de estimulacion de colonias granulociticas (G-CSF). De los 22 pacientes, nueve presentaron mejoria clinica, otros nueve pacientes fallecieron y de cuatro pacientes se desconoce su evolucion. T. asahii es un patogeno emergente en pacientes inmunodeficientes y su presencia en las muestras clinicas de estos no debe ser considerada una colonizacion por el importante riesgo de infeccion invasora. En aquellos pacientes susceptibles de padecer una Trichosporon osis se debe mantener alto grado de sospecha y vigilancia clinica para el diagnostico de esta infeccion.

Cryptococcus gattii fungemia: report of a case with lung and brain lesions mimicking radiological features of malignancy

A 64-year-old apparently immunocompetent white man developed lung and brain lesions of disseminated cryptococcosis. The radiologic features mimicked those of lung cancer metastatic to the central nervous system. C. gattii was recovered from cultures of bronchoalveolar lavage fluid, brain biopsy, and blood. The same fungus was recovered from pulmonary and brain specimens at autopsy. Serum and cerebrospinal fluid cryptococcal antigen tests were diagnostic in our case and should be included in the diagnostic evaluation of unexplained pulmonary and cerebral lesions. A literature search showed few reports of fungemia by this species of Cryptococcus, contrasting to C. neoformans.

Determination of germ tube, phospholipase, and proteinase production by bloodstream isolates of Candida albicans

INTRODUCTION Candida albicans is a commensal and opportunistic agent that causes infection in immunocompromised individuals. Several attributes contribute to the virulence and pathogenicity of this yeast, including the production of germ tubes (GTs) and extracellular hydrolytic enzymes, particularly phospholipase and proteinase. This study aimed to investigate GT production and phospholipase and proteinase activities in bloodstream isolates of C. albicans. METHODS One hundred fifty-three C. albicans isolates were obtained from blood samples and analyzed for GT, phospholipase, and proteinase production. The assays were performed in duplicate in egg yolk medium containing bovine serum albumin and human serum. RESULTS Detectable amounts of proteinase were produced by 97% of the isolates, and 78% of the isolates produced phospholipase. GTs were produced by 95% of the isolates. A majority of the isolates exhibited low levels of phospholipase production and high levels of proteinase production. CONCLUSIONS Bloodstream isolates of C. albicans produce virulence factors such as GT and hydrolytic enzymes that enable them to cause infection under favorable conditions.

Histoplasma capsulatum fungemia in patients with acquired immunodeficiency syndrome: detection by lysis-centrifugation blood-culturing technique

Progressive disseminated histoplasmosis (PDH) is an increasingly common cause of infection in patients with acquired immune deficiency syndrome (AIDS). We report 21 cases of PDH associated with AIDS diagnosed by lysis-centrifugation blood culture method. The most prevalent clinical findings were fever, weight loss, respiratory symptoms, and mucocutaneous lesions. Chest roentgenogram showed diffuse pulmonary infiltrates in 13 of 21 patients (62%). Bronchoalveolar fluid has yielded positive culture in four patients only in medium with cycloheximide.

Variability in Galactomannan detection by Platelia Aspergillus EIA™ according to the Aspergillus species.

Here we investigate the extent to which different Aspergillus species release galactomannan (GM) in vitro. Marked variability was observed in GM reactivity between and within Aspergillus species, with A. terreus strains showing the highest GM indexes. The in vivo significance of these findings remains to be determined.

Histoplasmose simulando neoplasia primária de pulmão ou metástases pulmonares

OBJECTIVE: To describe the main clinical and radiological characteristics of patients with histoplasmosis mimicking lung cancer. METHODS: This was a retrospective descriptive study based on the analysis of the medical records of the 294 patients diagnosed with histoplasmosis between 1977 and 2011 at the Mycology Laboratory of the Santa Casa Sisters of Mercy Hospital of Porto Alegre in the city of Porto Alegre, Brazil. The diagnosis of histoplasmosis was established by culture, histopathological examination, or immunodiffusion testing (identification of M or H precipitation bands). After identifying the patients with macroscopic lesions, as well as radiological and CT findings consistent with malignancy, we divided the patients into two groups: those with a history of cancer and presenting with lesions mimicking metastases (HC group); and those with no such history but also presenting with lesions mimicking metastases (NHC group). RESULTS: Of the 294 patients diagnosed with histoplasmosis, 15 had presented with lesions mimicking primary neoplasia or metastases (9 and 6 in the HC and NHC groups, respectively). The age of the patients ranged from 13 to 67 years (median, 44 years). Of the 15 patients, 14 (93%) presented with pulmonary lesions at the time of hospitalization. CONCLUSIONS: The clinical and radiological syndrome of neoplastic disease is not confined to malignancy, and granulomatous infectious diseases must therefore be considered in the differential diagnosis.OBJECTIVE: To describe the main clinical and radiological characteristics of patients with histoplasmosis mimicking lung cancer. METHODS: This was a retrospective descriptive study based on the analysis of the medical records of the 294 patients diagnosed with histoplasmosis between 1977 and 2011 at the Mycology Laboratory of the Santa Casa Sisters of Mercy Hospital of Porto Alegre in the city of Porto Alegre, Brazil. The diagnosis of histoplasmosis was established by culture, histopathological examination, or immunodiffusion testing (identification of M or H precipitation bands). After identifying the patients with macroscopic lesions, as well as radiological and CT findings consistent with malignancy, we divided the patients into two groups: those with a history of cancer and presenting with lesions mimicking metastases (HC group); and those with no such history but also presenting with lesions mimicking metastases (NHC group). RESULTS: Of the 294 patients diagnosed with histoplasmosis, 15 had presented with lesions mimicking primary neoplasia or metastases (9 and 6 in the HC and NHC groups, respectively). The age of the patients ranged from 13 to 67 years (median, 44 years). Of the 15 patients, 14 (93%) presented with pulmonary lesions at the time of hospitalization. CONCLUSIONS: The clinical and radiological syndrome of neoplastic disease is not confined to malignancy, and granulomatous infectious diseases must therefore be considered in the differential diagnosis.

Bola fúngica por Aspergillus fumigatus em cavidade pleural

OBJECTIVE To report the cases of 6 patients with fungus ball caused by Aspergillus fumigatus (aspergilloma) in the pleural cavity. METHODS Between 1980 and 2009, 391 patients were diagnosed with aspergilloma at the Santa Casa Hospital Complex in Porto Alegre, Brazil. The diagnosis of aspergilloma in the pleural cavity was made through imaging tests revealing effusion and pleural thickening with air-fluid level; direct mycological examination revealing septate hyphae, consistent with Aspergillus sp.; and positive culture for A. fumigatus in the surgical specimen from the pleural cavity. RESULTS Of the 391 patients studied, 6 (2%) met the established diagnostic criteria. The mean age of those 6 patients was 48 years (range, 29-66 years), and 5 (83%) were male. The most common complaints were cough, expectoration, and hemoptysis. Four patients (67%) had a history of tuberculosis that had been clinically cured. All of the patients were submitted to surgical removal of the aspergilloma, followed by intrapleural instillation of amphotericin B, in 4; and 2 received systemic antifungal treatment p.o. There was clinical improvement in 5 patients, and 1 died after the surgery. CONCLUSIONS In adult patients with a history of cavitary lung disease or pleural fistula, a careful investigation should be carried out and fungal infection, especially aspergilloma, should be taken into consideration. In such cases, laboratory testing represents the most efficient use of the resources available to elucidate the diagnosis.

Cutaneous infection by Diaporthe phaseolorum in Brazil

Diaporthe phaseolorum is a frequent fungal parasite of plants, rarely involved in human diseases. We describe a case of cutaneous infection caused by this fungus diagnosed by morphology and molecular biology, on the hands and on a foot of a renal transplanted Brazilian farmer. The infection was resolved with oral itraconazole.

Chronic Cavitary Pulmonary Aspergillosis and Fungal Balls

Chronic cavitary pulmonary aspergillosis (CCPA) is an Aspergillus-related disease that results in considerable morbidity. Most affected patients develop CCPA after lung damage caused by conditions such as tuberculosis. Fatigue and chronic cough are common symptoms and some patients may present with life-threatening haemoptysis. The diagnosis of CCPA relies on the presence of chronic respiratory symptoms in association with a positive serology/sputum to Aspergillus species and elevated serum inflammatory markers. Chest imaging is essential to evaluate the extent of the disease, to monitor disease progression and to evaluate for the presence of fungal balls. Since the majority of patients are not good surgical candidates due to limited lung function or extensive pleural involvement, long-term treatment with antifungal drugs are mandatory. This is however limited by the few available options for oral therapy and by cross-resistance between the azoles.