Cryptococcus neoformans causing meningitis in AIDS patients

Cryptococcus neoformans causes meningitis in AIDS patients. In the São José Hospital, reference center for patients with AIDS in Fortaleza - Ceará State - Brazil, 54 samples of the cerebrospinal fluid were analyzed from January 1st through December 31st 2000. Direct examination with India ink and culture in Sabouraud's agar at 37°C were done. Of the specimens studied 5(9.25%) were positive.

Cativeiro de aves como fonte de Cryptococcus neoformans na cidade de Campo Grande, Mato Grosso do Sul, Brasil

Cryptococcus neoformans é a levedura capsulada causadora de criptococose em humanos e animais. A variedade neoformans, encontrada em diversas fontes ambientais, inclusive habitats de aves, é importante causa de mortalidade em indivíduos com AIDS em todo o Mundo. Contudo, ainda não há estudos sobre a sua ecologia na região Centro Oeste brasileira, onde há registro da ocorrência de casos humanos da micose. Para estudar fontes saprofíticas de C. neoformans, na cidade de Campo Grande, foram coletadas 20 amostras de excretas de aves em distintos ambientes. Suspensão das amostras em salina estéril foram semeadas em placas com meio ágar níger. Após 5 dias, colônias mucóides marrom-escuro foram subcultivadas para identificação através de provas morfofisiológicas, determinação da variedade e sorotipagem. C. neoformans var. neoformans sorotipo A foi isolado de 10 (50%) das amostras, comprovando a ocorrência saprofítica de C. neoformans na cidade de Campo Grande, relacionada a habitat de aves em cativeiro.

Atividade antifúngica de Caryocar brasiliensis (Caryocaraceae) sobre Cryptococcus neoformans

A grande incidência de criptococose em decorrência do aumento crescente de indivíduos imunodeprimidos e os efeitos colaterais aos fármacos utilizados para o tratamento desta infecção, tem incentivado a pesquisa de novos agentes antifúngicos. Através da técnica de diluição em ágar, foi verificada a atividade antifúngica (in vitro) de diferentes constituintes de Caryocar brasiliensis sobre Cryptococcus neoformans. Verificou-se que a cera epicuticular retirada da folha, coletada em período de baixo índice pluviométrico (170,8mm de água), foi a parte mais ativa da planta, inibindo o crescimento de 91,3% (21/23) dos isolados de Cryptococcus neoformans em concentração < a 250µg/mL.

Vertical transmission of Cryptococcus neoformans from a mother coinfected with human immunodeficiency virus: case report

Disseminated infection with Cryptococcus neoformans was observed in a newborn infant who presented fever and respiratory symptoms since the 52nd day of life. The mother was infected by human immunodeficiency virus and presented pulmonary and meningeal cryptococcal infection. This is a rare case of cryptococcal infection with probable maternal-fetal transmission.

Comportamento de amostras ambientais e clínicas de Cryptococcus neoformans frente a fungicidas de uso agronômico e ao fluconazol

Avaliou-se a atividade de fungicidas azólicos de uso agronômico (epoxiconazol, difenoconazol e ciproconazol) em comparação ao antifúngico de uso terapêutico fluconazol sobre 23 amostras ambientais de Cryptococcus neoformans var neoformans isoladas de fezes de pombos, as quais foram coletadas em fazendas com práticas agrícolas empregando compostos azólicos e 11 amostras clínicas isoladas de pacientes portadores de criptococose. Os testes de sensibilidade foram realizados pela técnica de diluição em agar. A concentração inibitória mínima capaz de inibir 50% dos isolados ambientais (CIM 50) foi de 6,0µg/mL para epoxiconazol, 1,0µg/mL para difenoconazol, 2,0µg/mL para ciproconazol e 64,0µg/mL para fluconazol. Entre os isolados clínicos os valores de CIM 50 foram 2,0µg/mL, 0,38µg/mL, 1,0µg/mL e 16,0µg/mL para epoxiconazol, difenoconazol, ciproconazol e fluconazol, respectivamente. Os valores de CIM 50 em relação aos isolados de origem ambiental foram maiores do que os valores para os isolados de origem clínica. Em nosso estudo, frente ao mesmo antifúngico, as amostras ambientais apresentaram comportamento significativamente diferente em relação às amostras clínicas (p < 0,05). Diferenças (p<0,05) também foram observadas entre os valores de concentração inibitória apresentados pelo fluconazol e os outros antifúngicos de uso agronômico tanto no grupo dos isolados ambientais quanto clínicos.

Suscetibilidade a antifúngicos de variedades de Cryptococcus neoformans isoladas de pacientes em hospital universitário

Este trabalho identificou variedades de Cryptococcus neoformans e avaliou a suscetibilidade a antifúngicos pelo protocolo M27-A2 do National Committee for Clinical Laboratory Standards em isolados de 35 pacientes do Hospital Escola da Universidade Federal do Triângulo Mineiro. A variedade gatti foi identificada em 11.4% (nº = 4) dos casos. A concentração inibitória mínima (mg/ml) dos isolados de Cryptococcus neoformans neoformans variou de 0,062 - 2,000 (anfotericina B), 0,250 - 8,000 (fluconazol), 0,062 - 1,000 (itraconazol) e 0,125 - 1,000 (cetoconazol). A variedade gattii apresentou concentração inibitória mínima de 0,125 - 2,000 (anfotericina B), 0,250 - 16,00 (fluconazol), 0,062 - 1,000 (itraconazol) e 0,125 - 4,000 (cetoconazol). Detectaram-se 2 isolados resistentes ao itraconazol e 2 a anfotericina B (1 isolado de cada variedade por antifúngico). Os dados mostram a importância da determinação da variedade e da concentração inibitória mínima de isolados de Cryptococcus neoformans para monitorar o desenvolvimento de resistência e possibilitar uma terapia mais adequada na criptococose.

Ocorrência de Cryptococcus neoformans em excretas de pombos na cidade de Pelotas, Estado do Rio Grande do Sul

INTRODUÇÃO: O Cryptococcus neoformans é uma levedura capsulada, agente etiológico da criptococose em humanos e animais, encontrado em fontes ambientais, incluindo excretas de pombos, é uma importante causa de mortalidade em indivíduos imunodeprimidos em todo o mundo. MÉTODOS: Com o objetivo de verificar a ocorrência do Cryptococcus neoformans, em excretas de pombos, na Cidade de Pelotas, pesquisou-se 70 ambientes, incluindo prédios, praças e locais ao ar livre, da Cidade de Pelotas, RS. Após a coleta, os excrementos foram adicionados de salina com cloranfenicol, homogeneizados, semeados em ágar Sabouraud com cloranfenicol e ágar Níger e incubados a 32ºC. Para identificação, realizou-se exame direto, prova da fenoloxidase, urease, assimilação de carboidratos e cultura em meio CGB. RESULTADOS: Dos locais estudados (nº =70), em 26 (37,1%) havia excretas de pombos. Estes lugares foram representados por prédios históricos (nº =8), torre de igreja (nº =1), engenhos e armazéns de arroz (nº =7), praça (nº =1) e locais ao ar livre (nº =9), o isolamento de Cryptococcus neoformans ocorreu em 26,9% (nº =7/26), destes locais. CONCLUSÕES: O estudo chama a atenção, para o isolamento do fungo em áreas urbanas, que apresentavam grande acúmulo de excretas, indicando um risco para a saúde pública, especialmente para indivíduos imunocomprometidos.

Enzyme-linked immunosorbent assay for detection and quantification of Cryptococcus neoformans antigen

An enzyme-linked immunosorbent assay was standardized for the detection of cryptococcal antigen in serum and cerebrospinal fluid. The system was evaluated in clinical samples from patients infected by human immunodeficiency virus with and without previous cryptococcosis diagnosis. The evaluated system is highly sensitive and specific, and when it was compared with latex agglutination there were not significant differences. A standard curve with purified Cryptococcus neoformans antigen was settled down for the antigen quantification in positive samples.

In vitro susceptibility characteristics of Cryptococcus neoformans varieties from AIDS patients in Goiânia, Brazil

Sixty clinical isolates of Cryptococcus neoformans from AIDS from Goiânia, state of Goiás, Brazil, were characterized according to varieties, serotypes and tested for antifungal susceptibility. To differentiate the two varieties was used L-canavanine-glycine-bromothymol blue medium and to separate the serotypes was used slide agglutination test with Crypto Check Iatron. The Minimal Inhibitory Concentration (MIC) of fluconazole, itraconazole, and amphotericin B were determined by the National Committee for Clinical Laboratory Standards macrodilution method. Our results identified 56 isolates as C. neoformans var. neoformans serotype A and 4 isolates as C. neoformans var. gattii serotype B. MIC values for C. neoformans var. gattii were higher than C. neoformans var. neoformans. We verified that none isolate was resistant to itraconazole and to amphotericin B, but one C. neoformans var. neoformans and three C. neoformans var. gattii isolates were resistant to fluconazole. The presence of C. neoformans var. gattii fluconazole resistant indicates the importance of determining not only the variety of C. neoformans infecting the patients but also measuring the MIC of the isolate in order to properly orient treatment.

Antifungal activity from Ocimum gratissimum L. towards Cryptococcus neoformans

Cryptococcal infection had an increased incidence in last years due to the explosion of acquired immune deficiency syndrome epidemic and by using new and effective immunosuppressive agents. The currently antifungal therapies used such as amphotericin B, fluconazole, and itraconazole have certain limitations due to side effects and emergence of resistant strains. So, a permanent search to find new drugs for cryptococcosis treatment is essential. Ocimum gratissimum, plant known as alfavaca (Labiatae family), has been reported earlier with in vitro activity against some bacteria and dermatophytes. In our work, we study the in vitro activity of the ethanolic crude extract, ethyl acetate, hexane, and chloroformic fractions, essential oil, and eugenol of O. gratissimum using an agar dilution susceptibility method towards 25 isolates of Cryptococcus neoformans. All the extracts of O. gratissimum studied showed activity in vitro towards C. neoformans. Based on the minimal inhibitory concentration values the most significant results were obtained with chloroformic fraction and eugenol. It was observed that chloroformic fraction inhibited 23 isolates (92%) of C. neoformans at a concentration of 62.5 µg/ml and eugenol inhibited 4 isolates (16%) at a concentration of 0.9 µg/ml. This screening may be the basis for the study of O. gratissimum as a possible antifungal agent.

Superoxide dismutase in Cryptococcus neoformans varieties gattii, grubi, and neoformans

Some clear dissimilarities occur among the varieties of Cryptococcus neoformans but there are few studies about the differences among individual yeast antioxidant enzymes. The total superoxide dismutase (SOD) activities and the copper, zinc-depend SOD (Cu,ZnSOD) and manganese-dependent SOD (MnSOD) isoenzymes of five reference C. neoformans strains belonged to A, B, C, AD and D serotypes (Table I) and other nine C. neoformans isolates (Table II) were determined. There were significant differences (p < 0.01 and p < 0.05) in total SOD activity among the varietie gattii (serotype C) and the other varieties. Cu,ZnSOD showed difference (p < 0.05) between A and D serotypes. These results point out a variety and serotype-independent SOD activity in C. neoformans reference strains and the other isolates that were evaluated.

Evaluation of phenotypic and genotypic alterations induced by long periods of subculturing of Cryptococcus neoformans strains

Cryptococcus neoformans is an encapsulated fungal organism that can cause disease in apparently immunocompetent, as well as immunocompromised, hosts. Since 1930, successive subculture has been used to preserve C. neoformans isolates in our Fungus Collection. In the 1970s, some of these Fungus Collection samples were selected to be subjected to a different methods of maintenance - that of lyophilized. Our objective was to analyze C. neoformans isolates in order to make a comparative evaluation between these two methods of preservation. The overall aim of this study was to qualify the preservation technique used in our mycology laboratory since the technique used might affect the survival, stability and purity of the primary isolates in culture. The samples were analyzed using classical mycology methods and using the randomly amplified polymorphic DNA technique In the analysis of phenotypes and genotypes, the typical characteristics of C. neoformans were found to differ in relation to the different methods of preservation employed. The aim of this study was to demonstrate the importance of selecting the appropriate method of preservation for fungus collections. This selection can affect the survival and purity of the cultures, and preserve the stability of their physiological, biochemical, and genetic characteristics.

Molecular diversity of serial Cryptococcus neoformans isolates from AIDS patients in the city of São Paulo, Brazil

Despite highly active anti-retroviral therapy, cryptococcal meningoencephalitis is the second most prevalent neurological disease in Brazilian AIDS patients, being frequently a defining condition with several episodes. As knowledge of Cryptococcus neoformans isolates in the same episode is critical for understanding why some patients develop several episodes, we investigated the genotype characteristics of C. neoformans isolates in two different situations. By pulsed field gel electrophoresis and random amplifield polymorphic DNA analysis, 54 isolates from 12 patients with AIDS and cryptococcosis were analyzed. Group 1 comprised 39 isolates from nine patients with a single episode and hospitalization. Group 2 comprised 15 isolates from three patients with two episodes and hospitalizations. Except for three patients from group 1 probably infected with a single C. neoformans isolate, the other nine patients probably were infected with multiple isolates selected in different collection periods, or the infecting isolate might have underwent mutation to adapt and survive the host immune system and/or the antifungal therapy. However, the three patients from group 2 presented genetic diversity among isolates collected in both hospitalizations, possibly having hosted the initial isolate in both periods. These data, emphasize that Cryptococcus diversity in infection can contribute to strategies of treatment and prevention of cryptococcosis.

Regional pattern of the molecular types of Cryptococcus neoformans and Cryptococcus gattii in Brazil

The molecular types of 443 Brazilian isolates of Cryptococcus neoformans and Cryptococcus gattii were analyzed to determine their geographic distribution within Brazil and their underlying host conditions. The following data, imported from previous epidemiological studies as well as two culture collections, were analyzed for: place of isolation, source (clinical or environmental), host risk factors, species, serotype, mating type, and molecular type. Molecular typing by PCR-fingerprinting using primers for the minisatellite-specific core sequence of the wild-type phage M13 or microsatellites [(GACA)4, (GTG)5], restriction fragment length polymorphism of URA5 gene analysis, and/or amplified fragment length polymorphism (AFLP) identified eight major genotypes: VNI/AFLP1, VNII/AFLP1A, VNIII/AFLP2, and VNIV/AFLP3 for C. neoformans, and VGI/AFLP4, VGII/AFLP6, VGIII/AFLP5, and VGIV/AFLP7 for C. gattii. The most common molecular type found in Brazil was VNI (64%), followed by VGII (21%), VNII (5%), VGIII (4%), VGI and VNIV (3% each), and VNIII (< 1%). Primary cryptococcosis caused by the molecular type VGII (serotype B, MAT) prevails in immunocompetent hosts in the North and Northeast regions, disclosing an endemic regional pattern for this specific molecular type in the Northern Brazil.