Production of leukotriene B4 by Paracoccidioides brasiliensis

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

Cladophialophora saturnica sp nov., a new opportunistic species of Chaetothyriales revealed using molecular data

While many members of the black yeasts genus Cladophialophora have been reported to cause diseases in humans, understanding of their natural niche is frequently lacking. Some species can be recovered from the natural environment by means of selective isolation techniques. The present study focuses on a Cladophialophora strain that caused an interdigital tinea nigra-like lesion in a HIV-positive Brazilian child. The fungal infection was successfully treated with oxiconazole. Similar strains had been recovered from the environment in Brazil, Uruguay and the Netherlands. The strains were characterized by sequencing the Internal Transcribed Spacer (ITS) regions and the small subunit (SSU) of the nuclear ribosomal RNA gene, as well as the elongation factor 1-alpha (EF1) gene. Since no match with any known species was found, it is described as the new species, Cladophialophora saturnica.

In vitro antifungal susceptibility of Candida spp. oral isolates from HIV-positive patients and control individuals

Oropharyngeal candidiasis is the most common fungal infection among HIV-positive patients. This condition can be treated with either systemic or topical antifungal agents; treatments are usually indicated empirically on the basis of clinical data. The knowledge of in vitro antifungal susceptibility is important to determine correct therapeutic guides for the treatment of fungal infections. Therefore, the objective of this study was to determine the antifungal susceptibility profile of oral Candida isolates from HIV-positive patients and control individuals. Amphotericin B, fluconazole, flucytosine, nystatin and ketoconazole were tested according to the methodology of microdilution proposed by the Clinical and Laboratory Standards Institute (CLSI); results were recorded in values of minimal inhibitory concentration (MIC). A total of 71 Candida isolates from HIV-positive patients were examined with the following species represented: C. albicans (59), C. tropicalis (9), C. glabrata (1), C. guilliermondii (1) and C. krusei (1). A total of 15 Candida isolates were evaluated from control individuals comprised of 11 C. albicans and 4 C. tropicalis samples. Our results demonstrated that the tested antifungal agents showed good activity for most isolates from both groups; however, variability in MIC values among isolates was observed.

Paracoccidioidomicose em paciente com carcinoma do colo uterino

Os autores relatam caso de paciente do sexo feminino com paracoccidioidomicose, associada a carcinoma do colo uterino estádio IIIB. Paracoccidioidomicose, associada à neoplasia, ocorre entre 0,16% a 14,1% segundo diferentes séries de casos. em casos com neoplasia disseminada a infecção fúngicas pode apresentar comportamento oportunístico

Experimental paracoccidioidomycosis in hamsters (Mesocricetus auratus): Gestational interactions

Paracoccidioides brasiliensis is a dimorphic fungus presenting specific steroid hormone receptors, both in the yeast and mycelial forms and estrogen inhibits the transition from mycelium to yeast. In the acute phase, the disease occurs with equal frequency in both sexes but in adults, females are spared. Placental fungal infection has been reported, but references to fetal infection have not been confirmed. We used 78 Syrian female hamsters divided into 3 groups: GI consisted of 30 infected mated females, GII of 20 infected unmated females and GIII of 28 uninfected mated females. Animals of group I were mated 4 weeks after infection and half of them were submitted to cesarean section on day 15 after successful mating; the other half was maintained and submitted to cesarean section and sacrificed 14 weeks after infection. Half of the animals of group II were sacrificed seven weeks and the other half 14 weeks after infection. Uninfected animals of group III were treated the same as the animals of group I. The animals were infected with strain 18 of P. brasiliensis by the intracardiac route. We evaluated the disease by the volume of granulomas in different organs, number of fungi in liver and spleen and the immunologic responses [ELISA, Double Immunodifusion (DID), Delayed Hypersensitivity Skin Test (DHT) and Macrophage Migration Inhibition (MMI)]. We studied the infection through the gestation by evaluation of the abortions, morphologic and clinic examinations of the fetuses. Our results showed that the infection did not transfer to the fetus through the placenta, but the number of abortions was larger among infected females. The newborns of GI females were smaller, weighed less and showed little vitality. The disease was more severe and disseminated in infected mated females, especially in the second sacrifice 14 weeks after inoculation, when the total volume of granulomas in them (56.3 mm) was much greater than in the infected unmated females (12 mm).

Susceptibility of the cattle tick Boophilus microplus (Acari: Ixodidae) to isolates of the fungus Beauveria bassiana

The susceptibility of the tick Boophilus microplus to Beauveria bassiana was evaluated by inoculating eggs, larvae and engorged females of the tick with five fungal isolates at concentrations of 106, 107 and 108 conidia/ml. Tick eggs (0.25 g) were immersed in 1 ml of a suspension of the different conidial concentrations for 1 min. Similar exposure was performed by immersion of 2000 larvae and homogeneous groups of nine engorged females in 2 and 20 ml of conidial suspension, respectively. Treated eggs, larvae and adults were placed in an incubator at 27 ± 1 °C and relative humidity above 80% for evaluation of the fungal action. All fungal isolates applied at all conidial concentrations reduced the hatching rate of larvae from treated eggs by 1.36-65.58% and increased the mortality rate of inoculated larvae by 0.8-70.49%. In the bioassay with engorged females, oviposition period was reduced by 9.69-47.80%, egg mass weight by 4.71-53.87%, estimated reproduction by 8.3-60.62%, egg production index by 5.03-54.20%, percent larval hatching by 0.27-13.96%, and the mortality rate of treated females was increased by 96.60-100%. The reduction of the estimated reproduction obtained for the treated groups ranged from 8.37 to 64.52%. The sporulation of the pathogen on dead females ranged from 3.70 to 88.88% depending on the isolate and concentration used. Isolates AM 09, CB 7 and JAB 07 were the most effective and effectiveness increased with increasing concentrations of conidia in the suspensions.

Evaluation of DNA polymorphisms amplified by arbitrary primers (RAPD) as genetically associated elements to differentiate virulent and non-virulent Paracoccidioides brasiliensis isolates

Randomly amplified polymorphic DNA (RAPD) analysis of 35 Paracoccidioides brasiliensis isolates was carried out to evaluate the correlation of RAPD profiles with the virulence degree or the type of the clinical manifestations of human paracoccidioidomycosis. The dendrogram presented two main groups sharing 64% genetic similarity. Group A included two isolates from patients with chronic paracoccidioidomycosis; group B comprised the following isolates showing 65% similarity: two non-virulent, six attenuated, five virulent, eight from patients with chronic paracoccidioidomycosis and two from patients with acute paracoccidioidomycosis. The virulent Pb18 isolate and six attenuated or non-virulent samples derived from it were genetically indistinguishable (100% of similarity). Thus, in our study, RAPD patterns could not discriminate among 35 P. brasiliensis isolates according to their differences either in the degree of virulence or in the type of the clinical manifestation of this fungal infection. © 2002 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.

Sporotrichosis in an HIV-positive man with oral lesions: A case report

Background: Sporotrichosis is a granulomatous fungal infection caused by Sporothrix schenckii, which frequently causes cutaneous or lymphocutaneous lesions and rarely has oral manifestations. Case: A 38-year-old, white, HIV-positive man complained of a 5.0-cm, symptomatic, ulcerated lesion with thin, superficial granulation in the soft palate extending to the uvula. Exfoliative cytology of this oral lesion showed chronic granulomatous inflammatory alterations and extracellular fungal structures consisting of periodic acid-Schiff-positive budding cells and spherical or elongated (cigar bodies) free spore forms. Conclusion: The clinical and cytologic findings allowed the diagnosis of sporotrichosis, demonstrating the importance of cytodiagnosis in fungal diseases. © The International Academy of Cytology.

Paracoccidioidomycosis: No genetic damage in human peripheral blood cells of patients assessed by single-cell gel (comet) assay

Paracoccidioidomycosis is a systemic fungal infection caused by Paracoccidioides brasiliensis. As infectious diseases can cause DNA damage, the authors aimed at analyzing DNA breakage in peripheral blood cells of patients with paracoccidioidomycosis by using the comet assay. The results suggested that paracoccidioidomycosis does not cause genotoxicity.

It only takes one to do many jobs: Amphotericin B as antifungal and immunomodulatory drug

Amphotericin B acts through pore formation at the cell membrane after binding to ergosterol is an accepted dogma about the action mechanism of this antifungal, and this sentence is widely found in the literature. But after 60 years of investigation, the action mechanism of Amphotericin B is not fully elucidated. Amphotericin B is a polyene substance that is one of the most effective drugs for the treatment of fungal and parasite infections. As stated above, the first mechanism of action described was pore formation after binding to the ergosterol present in the membrane. But it has also been demonstrated that AmB induces oxidative damage in the cells. Moreover, amphotericin B modulates the immune system, and this activity has been related to the protective effect of the molecule, but also to its toxicity in the host. This review tries to provide a general overview of the main aspects of this molecule, and highlight the multiple effects that this molecule has on both the fungal and host cells. © 2012 Mesa-Arango, Scorzoni and Zaragoza.

Trafficking of phagocytic peritoneal cells in hypoinsulinemic-hyperglycemic mice with systemic candidiasis

Background: Candidemia is a severe fungal infection that primarily affects hospitalized and/or immunocompromised patients. Mononuclear phagocytes have been recognized as pivotal immune cells which act in the recognition of pathogens, phagocytosis, inflammation, polarization of adaptive immune response and tissue repair. Experimental studies have showed that the systemic candidiasis could be controlled by activated peritoneal macrophages. However, the mechanism to explain how these cells act in distant tissue during a systemic fungal infection is still to be elucidated. In the present study we investigate the in vivo trafficking of phagocytic peritoneal cells into infected organs in hypoinsulinemic-hyperglycemic (HH) mice with systemic candidiasis. Methods: The red fluorescent vital dye PKH-26 PCL was injected into the peritoneal cavity of Swiss mice 24 hours before the intravenous inoculation with Candida albicans. After 24 and 48 hours and 7 days of infection, samples of the spleen, liver, kidneys, brain and lungs were submitted to the microbiological evaluation as well as to phagocytic peritoneal cell trafficking analyses by fluorescence microscopy. Results: In the present study, PKH+ cells were observed in the peritoneum, kidney, spleen and liver samples from all groups. In infected mice, we also found PKH+ cells in the lung and brain. The HH condition did not affect this process. Conclusions: In the present study we have observed that peritoneal phagocytes migrate to tissues infected by C. albicans and the HH condition did not interfere in this process. © 2013 Fraga-Silva et al.; licensee BioMed Central Ltd.

Freqüência de fungos dermatófitos em (Felis catus) infectados e não infectados pelo vírus da imunodeficiência felina

Pós-graduação em Medicina Veterinária - FMVZ

Desinfecção de próteses totais por micro-ondas: efeito da frequência de irradiação no tratamento da estomatite protética

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

Influência da condição de hipoinsulinemia-hiperglicemia na candidíase experimental sistêmica: avalição da atividade macrofágica e da distribuição das subpopulações de monóciotos sanguíneos

Pós-graduação em Doenças Tropicais - FMB

Accumulation of a complex of pigments in sorghum mesocotyls in response to wounding

Sorghum mesocotyls upon mechanical injury with an abrasive (carborundum) or inoculation with the fungi Helminthosporium carbonum (non-pathogen) or Colletotrichum graminicola (pathogen) accumulate a methanol-soluble pigment complex with an absorption maximum around 480-490 nm. Spectral and thin-layer chromatographic analyses showed that the complexes which accumulated either in response to wounding or inoculation are similar. Thus, it is suggested that the accumulation of the pigmented phytoalexins in sorghum mesocotyls is a non-specific response of the tissues towards mechanical injury or fungal infection.