Efficacy of voriconazole in experimental rat paracoccidioidomycosis

INTRODUCTION: Amphotericin B, azole or sulfamide drugs are used for treatment of patients with paracoccidioidomycosis. Among the azole drugs, voriconazole was active in vitro against Paracoccidioides brasiliensis and showed efficacy in the treatment of patients infected with this fungus.In the present study the antifungal activity of voriconazole and of other drugs was compared in a rat model of paracoccidioidomycosis. METHODS: Wistar rats were inoculated intravenously with the BOAS strain of P. brasiliensis and antifungal drugs were administered to the animals by gavage at the following doses (mg/kg weight/day): voriconazole (5 to 20), ketoconazole (12 to 15), fluconazole (6), itraconazole (4), and sulfamethoxazole-trimethoprim (120 to 150). The antifungal activity of the drugs was assessed by determining the P. brasiliensis colony forming units in the lungs and spleen of the animals at the end of treatment and by a survival study. RESULTS: Voriconazole reduced the total tissue fungal burden of P. brasiliensis, particularly at doses of ≥10mg/kg weight/day but its antifungal activity was less intense than that of fluconazole, itraconazole and sulfamethoxazole-trimethoprim. The mean survival of animals treated with the last three drugs, 29.1±10.7, 26.1± 10.1 and 28.4±9.6 days, respectively, was higher than that achieved with voriconazole 10mg/kg weight/day (18.5±8.3 days) and that observed in untreated animals (15.7±3.6 days). CONCLUSIONS: At doses similar to those used for clinical treatment, voriconazole showed lower antifungal activity in experimental rat paracoccidioidomycosis than that obtained with itraconazole and sulfamethoxazole-trimethoprim.

Paracoccidioidomycosis in a western Brazilian Amazon State: Clinical-epidemiologic profile and spatial distribution of the disease

Introduction: Paracoccidioidomycosis (PCM) is a systemic infection caused by the fungus Paracoccidioides brasiliensis. PCM is considered one of the most important systemic mycoses in Latin America. Methods: This is a clinical, epidemiological, retrospective, quantitative study of PCM cases in patients attending the National Health Service in the State of Rondônia in 1997-2012. The examined variables included sex, age group, year of diagnosis, education level, profession, place of residence, diagnostic test, prior treatment, medication used, comorbidities and case progress. Results: During the study period, 2,163 PCM cases were registered in Rondônia, and the mean annual incidence was 9.4/100,000 people. The municipalities with the highest rates were located in the southeastern region of Rondônia, and the towns of Pimenteiras do Oeste and Espigão do Oeste had the highest rates in the state, which were 39.1/100,000 and 37.4/100,000 people, respectively. Among all cases, 90.2% and 9.8% were observed in men and women, respectively, and most cases (58.2%) were observed in patients aged between 40 and 59 years. Itraconazole was used to treat 91.6% (1,771) of cases, followed by sulfamethoxazole in combination with trimethoprim (4.4% [85] of cases). One hundred thirty-one (6%) patients died. Conclusions: The State of Rondônia has a high incidence of PCM, and the municipalities in the southeastern region of the state were found to have the highest incidence rates of this disease. Our findings suggest that Rondônia is the state in the northern region with the highest mortality rate for PCM.

Eco-epidemiologic study of emerging fungi related to the work of babaçu coconut breakers in the State of Maranhão, Brazil

Introduction: There are more than 300,000 extractors using the babaçu coconut as a source of income in the States of Maranhão, Pará, Tocantins and Piauí, and this activity is associated with fungal infections. The objective of this study was to examine the occurrence of emergent fungi in the conjunctiva, nails and surface and subcutaneous injuries of female coconut breakers in Esperantinópolis, Maranhão. Additionally, soil samples and palm structures were collected. Methods: The obtained samples were cultured in Petri dishes containing potato-dextrose-agar and chloramphenicol. The etiological agent was confirmed by a direct mycological exam and growth in culture. Results: In total, 150 domiciles were visited, and samples were collected from 80 patients. From the ground, the most frequently isolated fungus was Aspergillus niger (53. 8%). the most frequently detected fungus in babaçu coconut was Aspergillus niger (66.7%). Conjunctival fungal growth occurred in 76.3% of the women. The ocular fungal microbiota consisted of filamentous fungi (80.6%), and yeasts were present in 19.4% of cases. Onychomycosis was diagnosed in 44% (11/25) of the women. Conclusions: The identification of the genera Neosartorya, Rhizopus and Curvularia in onychomycoses shows that emergent filamentous fungi can be isolated. Aspergillus sp., Penicillium sp. and Scedosporium sp. were the predominant genera found in the babaçu coconut. From ocular conjunctiva, Candida spp. were the most prevalent species isolated, and Fusarium sp. was present only in one woman. The nearly permanent exposure of coconut breakers to the external environment and to the soil is most likely the reason for the existence of a mycotic flora and fungal infections, varying according to the individual's practices and occupation.

Daldinia eschscholtzii (Ascomycota, Xylariaceae) isolated from the Brazilian Amazon: taxonomic features and mycelial growth conditions

The Amazon has a high diversity of fungi, including species of the genus Daldinia (Ascomycota, Xylariaceae), which produce secondary metabolites with recognized nematicidal and antimicrobial activity. The ecological role of Daldinia is important, as stromata serve as refuges to many insects and arthropodes, and the fungi contribute to the degradation of vegetable organic matter. The aim of this study was to analyze the taxonomic features and mycelial growth conditions in vitro of a Daldinia specimen collected in the Brazilian Amazon. Morphological and molecular studies of the fungus identified it as D. eschscholtzii. To evaluate mycelial growth, we cultivated the fungus at 20, 25, 30, 35, and 40 °C in malt extract-peptone agar (MEPA), malt extract-peptone (MEP), potato dextrose (PD), and minimum medium (MM). The best mycelial growth occurred at 35 °C, although the greatest amount of biomass was obtained at 25 °C and 30 °C. PD proved to be the best medium for biomass production.

Diversity and capacity to promote maize growth of bacteria isolated from the Amazon region

ABSTRACT Maize plants can establish beneficial associations with plant growth-promoting bacteria. However, few studies have been conducted on the characterization and inoculation of these bacteria in the Amazon region. This study aimed to characterize endophytic bacteria isolated from maize in the Amazon region and to assess their capacity to promote plant growth. Fifty-five bacterial isolates were obtained from maize grown in two types of ecosystems, i.e., a cerrado (savanna) and a forest area. The isolates were characterized by the presence of the nifH gene, their ability to synthesize indole-3-acetic acid (IAA) and solubilize calcium phosphate (CaHPO4), and 16S rRNA partial gene sequencing. Twenty-four bacteria contained the nifH gene, of which seven were isolated from maize plants cultivated in a cerrado area and seventeen from a forest area. Fourteen samples showed the capacity to synthesize IAA and only four solubilized calcium phosphate. The following genera were found among these isolates: Pseudomonas; Acinetobacter; Enterobacter; Pantoea; Burkholderia and Bacillus. In addition, eight isolates with plant growth-promoting capacity were selected for a glasshouse experiment involving the inoculation of two maize genotypes (a hybrid and a variety) grown in pots containing soil. Inoculation promoted the development of the maize plants but no significant interaction between maize cultivar and bacterial inoculation was found. A high diversity of endophytic bacteria is present in the Amazon region and these bacteria have potential to promote the development of maize plants.

Infection by microorganisms on soybean seeds obtained from plants treated with growth regulators

This research, deals with the effects of exogenous growth regulators on infection by microorganisms on soybean (Glycine max cv. Davis) seeds. To study the influence of the chemicals, soybean plants were sprayed with gibberellic acid (GA) 100 ppm, (2-chloroethyl) trimethylammonium chloride (CCC) 2,000 ppm, succinic acid-2,2-dimethy1hydrazide (SADH) 4,000 ppm, indolylacetic acid (IAA) 100 ppm, 2,3,5-triiodobenzoic acid (TIBA) 20 ppm (three applications), and Agrostemin (1g/10 ml/ 3 1). Application of growth regulators did not affect infect ion by microorganisms on soybean seeds. The prominent fungus isolated was Phomopsis sojae. Alternaria and Fusarium spp. were isolated from seeds. The presence of a bacterium on the seeds was observed. The delay in harvest and high humidity increased the number of seeds from which Phomopsis was recovered.

Ensaios de Mycologia

Morphologically the fungus reminds one of the Microsporum species of man. The microscopic elements are: the shape of the mycelia within the hairs, size and disposition of spores intercalar and terminal chlamydospores, simple clusters, hyphae, pectinate and denticulate elements. Of the 17 species of Microsporum described up to now, none can be identified with Microsporum circuluscentrum. The microsporum described is of the pure-by human type. (Culture fairly vivacious, almost total absence of spindles.) Microscopically at first sight the culture might be taken for Microsporum fulvum URIBURU 1917 or for M. felineum. These are however from animals. The bean shaped culture on potatoes leaves a place apart for it among Microsporum fungi. The anomalous elements seen in the cultures are also found in other species of Microsporum. Besides the pseudo-perithecia described and interpreted I must mention that the pseudo-nodular organs are not an exception among these fungi, for Microsporum fulvum also shows what writers have described as nodular organs. The spiral elements are also not exclusive features of the trichophytes. Microsporum tardum also shows quite characteristic spiral forms.

Dermatite verrucosa leprotica (Estudo de 3 casos)

The writer has discovered in Curupaity (National Leprosarium, Rio de Janeiro), three cases of verrucous dermatitis in C 3 type lepers. He suspected it to be an association of leprosy with Dermatilis verrucosa blastomycetica (Chromoblastocycosis) but various attempts to cultivate the fungus (Acrotheca or Hormodendrum Pedrosoi) responsible for the disease gave negative results and also the histopathologic aspect of the verrucous tissue proved it to be a leprotic granuloma without mycotic association. The writer's conclusion, based upon the cultural and histopathological studies, is that the verrucous dermatitis observed is due to leprosy alone, considering it as a new syndrome of the disease and not a new clinical form. He has called it « Dermatitis verrucosa leprotica » and made suggestions to all doctors of leprosaria to look for new cases and to study their etiology and pathogeny. Electrocoagulation improved the lesions.

Verificação da infecção de moscas da família Tachinidae pela Empusa Cohn, 1855: essas moscas, sugando ulceras lepróticas, se infestaram com o bacilo de Hansen

The A. refers that, in his last study, in his last studying trip to Colonia Santa Fé, Minas Gerais State, last month of March (autumn), had captured many wild flies (all from Tachinidae family, according to various entomologists of the Instituto Oswaldo Cruz), on a leprotic ulceration of the left leg of a lepromatous case of leprosy. The microscopical examination of the abdominal material from sch flies proved the presence, in rather great number, of HANSEN bacilli and a fungus of the genus Empusa COHN 1855. The A. intends to continue, next summer, such interesting research.

A medium for inducing conversion of Histoplasma capsulatum var. capsulatum into its yeast-like form

Histoplasma capsulatum var. capsulatum is a dimorphic fungus that, under special conditions, converts from its more common mycelial form to a yeast-like form. Achieving this conversion, however, has been problematical for researchers. The present study tested conversion rates in ten Histoplasma capsulatum var. capsulatum strains using seven culture media, four of wich were conventional and three novel. One of our novel media, MLGema, induced complete conversion, of two strains within five days of incubation at 35 degrees centigrades, and of all strains that eventually converted by the time of the second subculturing transfer, under defined experimental conditions. MLGema is also inexpensive and easy to produce.

Histopathological alterations induced by non-viable cells and biochemical fractions from Paracoccidioides brasiliensis in mice

Non-viable cells and biochemical fractions from Paracoccidioides brasiliens were obtained for experimental inoculation in mice and posterior histopatological analysis. Dead total fungus, total fungus disrupted by sonorous waves, lipids of the fungus, supernatant of the lipid purification, integral and disrupted fungus free of lipids were obtained. The six preparations arised from masses of lyophilized yeasts of a recent isolate of P. brasiliensis (strain JT-1) and from a "Pool" equitably constituted by four strains maintained in laboratory for a long time (SN, 2, 18 and 192). Different doses of the 12 preparations were intraperitonially inoculated and histopathological analysis were done 30 days later. This analysis showed that all the inoculated preparations gave origin to inflamatory foci, except the one designated "supernatant of lipid purification". The alterations were detected exclusively in the liver of the animals and occurred from the smallest dose tested (1 mg), with exception of the lipids of the fungus, where the foci appeared only from a 3 mg dose onwards. No difference in the capacity of inducing histopathological alterations was found between the preparations obtained from the recent isolate (JT-1) and from the older ones ("Pool"). On the other hand, an increase of the number of inflammatory foci in function of the inoculated dose was observed.

Chromoblastomycosis murine model and in vitro test to evaluate the sensitivity of Fonsecaea pedrosoi to ketoconazole, itraconazole and saperconazole

An experimental model of murine chromoblastomycosis and in vitro tests with Fonsecaea pedrosoi were used to test the sensitivity of this fungus to three different antimycotics. The experimental model was standardized in BALB/c mice inoculated intraperitoneally with a 10(6) CFU/ml suspension of a F. pedrosoi isolate. Clinical infection was evident after 5 days of inoculation. Three groups of 27 mice each were used in the experiment. One group was treated with ketoconazole (KTZ), another with itraconazole (ITZ) and the other with saperconazole (SPZ). Antimycotic therapy was continued for 21 days. The control group consisted of 40 mice which were inoculated, but not treated. Infection was documented by macroscopic and microscopic examination of affected tissue in addition to culture of tissue macerates. Minimal inhibitory concentrations (MIC) and minimal fungicidal concentrations (MFC) for the F. pedrosoi strain used were done. The in vitro results showed that SPZ was the most active with MIC 0.01 mg/ml and MFC 0.1 mg/ml, followed by ITZ. SPZ was also the most effective in vivo since 63% of the treated animals (p=0.01) showed a curative effect after the observation period. We concluded that SPZ had the best in vitro and in vivo activity against F. pedrosoi.

The marsupial Didelphis albiventris is an improbable host of Paracoccidioides brasiliensis in an endemic area of paracoccidioidomycosis in Minas Gerais, Brazil

To determine whether Didelphis albiventris is naturally infected with Paracoccidioides brasiliensis, 20 specimens of this mammal were studied by both direct cultivation of their viscera (spleen, liver and lungs) and by inoculation of Swiss mice by the intraperitoneal route with a suspension of fragments of these viscera. No fungal growth or structures similar to this fungus were detected. Probably D. albiventris is not frequently infected with P. brasiliensis.

Polygodial, the fungitoxic component from the Brazilian medicinal plant Polygonum punctatum

Polygonum punctatum (Polygonaceae) is an herb known in some regions of Brazil as "erva-de-bicho" and is used to treat intestinal disorders. The dichloromethane extract of the aerial parts of this plant showed strong activity in a bioautographic assay with the fungus Cladosporium sphaerospermum. The bioassay-guided chemical fractionation of this extract afforded the sesquiterpene dialdehyde polygodial as the active constituent. The presence of this compound with antibiotic, anti-inflammatory and anti-hyperalgesic properties in "erva-de-bicho" may account for the effects attributed by folk medicine to this plant species.

The Histopathology of the Infection of Tilapia rendalli and Hypostomus regani (Osteichthyes) by Lasidium Larvae of Anodontites trapesialis (Mollusca, Bivalvia)

It is described the histopathology of the infection of Tilapia rendalli (Osteichthyes, Perciformes, Cichlidae) and Hypostomus regani (Osteichthyes, Siluriformes, Loricariidae) by lasidium larvae of Anodontites trapesialis (Mollusca, Bivalvia, Mycetopodidae). The larvae were encysted within the epidermis of the host, being surrounded by a thin hyaline membrane, 3-6 µm thick, of parasite origin. A proliferative host cell reaction did not occur. The histopathology of the infection shows that the lesions induced by the parasites are minimal. However, the numerous small lesions produced by the release of the larvae may provide optimal conditions for the infection by opportunistic pathogens, namely fungus, which may eventually cause the death of the host.