Antimicrobial activity of Pterogyne nitens Tul., Fabaceae, against opportunistic fungi

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Virulence Factors IN Fungi of Systemic Mycoses

Fatores de virulência em fungos de micoses sistêmicaFungos patogênicos causadores de micoses sistêmicas possuem vários fatores que permitem seu crescimento nas condições adversas oferecidas pelo hospedeiro, propiciando o estabelecimento da relação parasitária e contribuindo no processo de doença. Esses fatores são conhecidos como fatores de virulência auxiliando no desenvolvimento da infecção e interferindo com a patogênese das micoses. O presente trabalho avalia os fatores de virulência em fungos patogênicos como Blastomyces dermatitidis, Coccidioides immitis, Cryptococcus neoformans, Histoplasma capsulatum e Paracoccidioides brasiliensis, em relação à termotolerância, dimorfismo, componentes da parede celular ou cápsula, bem como a produção de enzimas. Os fatores de virulência auxiliam na aderência, colonização, disseminação e habilidade do fungo para resistir a ambientes hostis e escapar dos mecanismos da resposta imune do hospedeiro.Tanto os fatores de virulência apresentados por diferentes fungos, como os mecanismos de defesa oferecidos pelo hospedeiro requerem ação e interação de processos complexos, cujo conhecimento permitirá a melhor compreensão da patogenia das micoses sistêmicas.

Cryptococcosis outbreak in psittacine birds in Brazil

An outbreak of cryptococcosis occurred in a breeding aviary in São Paulo, Brazil. Seven psittacine birds (of species Charmosyna papou, Lorius lory, Trichoglossus goldiei, Psittacula krameri and Psittacus erithacus) died of disseminated cryptococcosis. Incoordination, progressive paralysis and difficulty in flying were seen in five birds, whereas superficial lesions coincident with respiratory alterations were seen in two birds. Encapsulated yeasts suggestive of Cryptococcus sp. were seen in faecal smears stained with India ink in two cases. Histological examination of the birds showed cryptococcal cells in various tissues, including the beak, choana, sinus, lungs, air sacs, heart, liver, spleen, kidneys, intestines and central nervous system. High titres of cryptococcal antigen were observed in the serum of an affected bird. In this case, titres increased during treatment and the bird eventually died. Yeasts were isolated from the nasal mass, faeces and liver of one bird. Cryptococcus neoformans var. gattii serovar B was identified based on biochemical, physiological and serological tests. These strains were resistant (minimum inhibitory concentration 64 μ g/ml) to fluconazole. This is the first report of C. neoformans var. gattii occurring in psittacine birds in Brazil. © 2004 ISHAM.

Comparative study of disk diffusion and microdilution methods for evaluation of antifungal activity of natural compounds against medical yeasts Candida spp and Cryptococcus sp

Antifungal activity of natural products has been tested by adapting methods designed for synthetic drugs. In this study, two methods for the determination of antifungal activity of natural products, agar diffusion and broth microdilution, the CLSI reference methods for synthetic drugs, are compared and discussed. The microdilution method was more sensitive. The minimal inhibitory concentrations (MIC) of crude extracts, fractions and pure substances from different species of the plant families Piperaceae, Rubiaceae, Clusiaceae, Fabaceae and Lauraceae, from the Biota project, were determined. Antifungal activities against Candida albicans, C.krusei, C.parapsilosis and Cryptococcus neoformans were produced by several samples.

Cryptococcus gattii and Cryptococcus albidus in captive domestic Pigeon (Columba livia)

Cryptococcosis in animals is an important fungal disease caused by the encapsulated yeast Cryptococcus neoformans. This report describes the occurrence of Cryptococcus gattii and Cryptococcus albidus in domestic pigeon (Columba livia), living together with other birds in a breeding center. The animal presented a pinkish, vascularized mass with gelatinous aspect localized subcutaneously under the right lower eyelid, with approximately 2cm in diameter. At microbiological exam it was isolated Cryptococcus gatti from the eyelid mass, lungs and liver, C. albidus from the trachea and both Cryptococcus species from muscle and kidney.

Dynamics and Conformational Studies of TOAC Spin Labeled Analogues of Ctx(Ile21)-Ha Peptide from Hypsiboas albopunctatus

Antimicrobial peptides (AMPs) isolated from several organisms have been receiving much attention due to some specific features that allow them to interact with, bind to, and disrupt cell membranes. The aim of this paper was to study the interactions between a membrane mimetic and the cationic AMP Ctx(Ile21)-Ha as well as analogues containing the paramagnetic amino acid 2,2,6,6-tetramethylpiperidine-1-oxyl-4-amino-4-carboxylic acid (TOAC) incorporated at residue positions n = 0, 2, and 13. Circular dichroism studies showed that the peptides, except for [TOAC13]Ctx(Ile21)-Ha, are unstructured in aqueous solution but acquire different amounts of α-helical secondary structure in the presence of trifluorethanol and lysophosphocholine micelles. Fluorescence experiments indicated that all peptides were able to interact with LPC micelles. In addition, Ctx(Ile21)-Ha and [TOAC13]Ctx(Ile21)-Ha peptides presented similar water accessibility for the Trp residue located near the N-terminal sequence. Electron spin resonance experiments showed two spectral components for [TOAC0]Ctx(Ile21)-Ha, which are most likely due to two membrane-bound peptide conformations. In contrast, TOAC2 and TOAC13 derivatives presented a single spectral component corresponding to a strong immobilization of the probe. Thus, our findings allowed the description of the peptide topology in the membrane mimetic, where the N-terminal region is in dynamic equilibrium between an ordered, membrane-bound conformation and a disordered, mobile conformation; position 2 is most likely situated in the lipid polar head group region, and residue 13 is fully inserted into the hydrophobic core of the membrane. © 2013 Vicente et al.

Cryptococcosis: epidemiology, fungal resistance, and new alternatives for treatment

Cryptococcosis is an important systemic mycosis and the third most prevalent disease in human immunodeficiency virus (HIV)-positive individuals. The incidence of cryptococcosis is high among the 25 million people with HIV/acquired immunodeficiency syndrome (AIDS), with recent estimates indicating that there are one million cases of cryptococcal meningitis globally per year in AIDS patients. In Cryptococcus neoformans, resistance to azoles may be associated with alterations in the target enzyme encoded by the gene ERG11, lanosterol 14α-demethylase. These alterations are obtained through mutations, or by overexpressing the gene encoding. In addition, C. gattii and C. neoformans present a heteroresistance phenotype, which may be related to increased virulence. Other species beyond C. neoformans and C. gattii, such as C. laurentii, have been diagnosed mainly in patients with immunosuppression. Infections of C. albidus have been isolated in cats and marine mammals. Recent evidence suggests that the majority of infections produced by this pathogen are associated with biofilm growth, which is also related with increased resistance to antifungal agents. Therefore, there is a great need to search for alternative antifungal agents for these fungi. The search for new molecules is currently occurring from nanoparticle drugs of plant peptide origin. This article presents a brief review of the literature regarding the epidemiology of cryptococcosis, as well as fungal resistance and new alternatives for treatment. © 2013 Springer-Verlag Berlin Heidelberg.

Antifúngicos naturais e sintéticos: estudo dos mecanismos de ação em sistema de infecção in vitro empregando cepas de Cryptococcus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo microbiológico: amostragem de Cryptococcus sp em São José do Rio Preto/SP

Pós-graduação em Microbiologia - IBILCE

Kalanchoe gastonis-bonnieri Rayn.-Hamet & H.Perrier e Kalanchoe pinnata Pers. (Crassulaceae): atividade antifúginca e estudo farmacognóstico comparativo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Síntese, caracterização e investigação da atividade biológica de complexos de cobre e paládio contendo ligantes N,S doadores

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo químico e biológico de fungos endofíticos associados com a alga vermelha Dichotomaria marginata (Galaxauraceae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Primary endemic Cryptococcosis gattii by molecular type VGII in the state of Pará, Brazil

In order to study the infectious agents causing human disseminated cryptococcosis in the state of Pará, North Brazil, 56 isolates of Cryptococcusspp. (54 isolated from cerebral spinal fluid and two from blood cultures) from 43 cases diagnosed between 2003-2007 were analysed. The species were determined through morphological and physiological tests and genotypes were determined by URA5-RFLP and PCR-fingerprinting (wild-type phage M13). The following species and genotypes were identified: Cryptococcus neoformans VNI (28/56, 50%), Cryptococcus gattii VGII (25/56, 44.64%) and C. gattii VGI (3/56, 5.26%). The genotype VNI occurred in 12 out of 14 HIV-positive adults, whereas the genotype VGII occurred in 11 out of 21 HIV-negative adults (p < 0.02, OR = 6.6 IC95% 0.98-56.0). All patients less than 12 years old were HIV negative and six cases were caused by the VGII genotype, one by the VGI and one by VNI. Therefore, endemic primary mycosis in HIV-negative individuals, including an unexpectedly high number of children, caused by the VGII genotype deserves further study and suggests the need for surveillance on cryptococcal infection in the state of Pará, Eastern Amazon.

Perfil clínico-epidemiológico da Criptococose em pacientes HIV positivos atendidos em uma unidade de referência em Belém do Pará

A criptococose em residentes no estado do Pará apresenta-se como endemia grave, ocorrendo nas diferentes mesorregiões do estado e na área metropolitana de Belém. Ocorre causando neurocriptococose, com letalidade acima de 40%. Para tentar elucidar o comportamento clínico e epidemiológico da criptococose em pacientes HIV positivos, realizamos um estudo retrospectivo, analítico de série de casos, com revisão de prontuários dos últimos 05 anos (2006 –2010), com pacientes HIV positivos em um hospital de referência em Belém – Pará. A doença ainda é uma das causas mais freqüentes de óbitos em pacientes HIV positivos na região norte e deve-se ao C. neoformans o maior número de casos, contribuindo com 57 (60,6%) de um total de 94 casos. No que diz respeito à forma clínica, da criptococose, desenvolvida pelos pacientes HIV positivos, observou-se que o acometimento do sistema nervoso está presente em 46,8% dos pacientes e a disseminação da doença em 27,7% dos casos. A relação entre a causa do óbito e a presença do Cryptococcus, ocorre por um conjunto complexo de fatores que devem ser esclarecidos e correlacionados com o óbito dos pacientes e o mais importante, estabelecerem o quão forte é essa relação uma vez detectada.

Criptococose em crianças no Estado do Pará, Brasil

Relatam-se 19 casos de criptococose em crianças, diagnosticados em Belém, PA. Em nove pacientes a variedade do agente etiológico foi estudada e identificada como Cryptococcus neoformans var. gattii. A média de idade destes pacients foi 7,8 anos (variação, 5-13 anos). Havia 5 meninas e 4 meninos (razão, 1,25:1). Cinco foram a óbito em três meses apesar do tratamento com anfotericina B (associada com fluconazol 3 ou fluocitosina 1). São comentados a existência de áreas de alta endemia da infecção por var. gattii no Pará e a gravidade da doença causada por essa variedade fúngica.