Maria do Rosário Rodrigues Silva

Antifungal activity of volatile constituents of Eugenia dysenterica leaf oil

The essential oil from the hydrodistillation of Eugenia dysenterica leaves consisted mainly of beta-caryophyllene and alpha-humulene as the major sesquiterpene, while limonene and alpha-thujene were the major monoterpene hydrocarbons. The main oxygenated mono and sesquiterpene constituents were alpha-terpineol and beta-caryophyllene oxide, respectively. The oil was investigated against eight strains of Candida albicans, 35 strains of Cryptococcus neoformans var. neoformans, and two C. neoformans var. gattii isolated from HIV-infected individuals with candidosis or cryptococcal meningitis using the agar dilution method. Based on the minimal inhibitory concentration (MIC) values, the most significant results were obtained against Cryptococcus strains. It was observed that 22 strains were inhibited at a concentration of 250 microg/ml, whereas four exhibited potent inhibition with MIC values below 125 microg/ml against 10(6) UFC/ml organisms. We found MICs > or = 3.12 microg/ml for 91.6, 50 and 30% of all Cryptococcus strains in relation of amphotericin B, fluconazole and itraconazole, respectively.

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 microg/ml and eugenol inhibited 4 isolates (16%) at a concentration of 0.9 microg/ml. This screening may be the basis for the study of O. gratissimum as a possible antifungal agent.

Candiduria in hospital patients: A study prospective

The presence of Candida species in the urine is frequent among hospitalized patients. We studied sample urine of 205 hospitalized patients during a 1-year period to determine the incidence of nosocomial candiduria. The yeasts were isolated in 22% (45/205) urine cultures and risk factors in these patients were analyzed. Candida albicans was isolated in 35.6% and C. tropicalis (22%) was the second most frequent species isolated. Most patients were women (57.8%) with a mean age of 48.7 years. The principal risk factors that were observed in patients with candiduria included antibiotics therapy (100%), urinary catheterization (84.4%), surgical procedure (66.7%), female sex and extended hospitalization. The efficacy of fluconazole therapy to eradicate Candida from urine was demonstrated (p = 0.05). Of the 23 individuals who received antifungal therapy, candiduria persisted in 9 (39.2%) and of 22 patients who received no antifungal therapy, the candiduria persisted in 15 (68.2%).

Candida colonization in intensive care unit patients' urine

The objective of this study was to identify possible predisposing factors for candiduria in intensive care unit (ICU) patients from Hospital das Clínicas, Universidade Federal de Goiás, Goiânia, Brazil, during one year. Urine samples from 153 ICU patients were obtained by catheterization on admission day and every seven days. Data such as sex, age, antifungal therapy, and variables as antibiotics, underlying diseases or comorbid conditions and stay in the hospital, were collected from patients who had at least one urine culture that yielded > 10(3) yeast colonies/ml. Candiduria was recovered in 68 patients and the commonest predisposing factors were antibiotic therapy (100%) and indwelling urinary catheter (92.6%). The percentage of Candida spp. isolation increased during the extended periods in which patients remained in the ICU. C. albicans was isolated in 69.1%, and the other species non-albicans as C. glabrata, C. kefyr, C. parapsilosis, C. famata, C. guilliermondii, C. krusei, and C. tropicalis were isolated in lower percentage. The high frequency of candiduria and the possible predisposing factors found in ICU patients show that candiduria surveillance should be performed to help reducing nosocomial infections.

Avaliação do cetoconazol em camundongos inoculados com Paracoccidioides brasiliensis pela histopatologia de fígado e baço e pela intradermorreação de paracoccidioidina

Male albino mice were inoculated intravenously with 0.5 x 10(7) viable yeast forms of P. brasiliensis (strain 2052). These animals were treated with two doses of ketoconazole (50 and 100 mg/kg) during fifty days and the sacrificed. We studied the presence of P. brasiliensis, the inflammatory granulomatous response of liver and spleen and the anti P. brasiliensis delayed hypersensitivity response measured by the footpad test after 48 hours. It was observed that: 1. animals infected and treated with ketoconazole showed reduction in the number of fungi in the organs studied; 2. there was no difference in the number of granulomas among animals treated and non-treated; 3. the cutaneous delayed tests intensity was similar in all animals.

Antimicrobial activity of Hyptis ovalifolia towards dermatophytes

The essential oil and the aqueous, hexane and methanolic fractions from Hyptis ovalifolia leaves were evaluated for their antifungal activity in vitro against 60 strains of dermatophytes: 10 strains of Microsporum canis, 10 of M. gypseum, 20 of Trichophyton rubrum and 20 of T. mentagrophytes. The extracts inhibited growth of the dermatophytes tested at different concentrations. The most biologically active was the essential oil from the leaves which inhibited 57 isolates (95%) at a concentration of 500 g/ml.

Epidemiologia e etiologia das dermatofitoses em Goiânia, GO, Brasil

Dermatophytes are a group of closely related fungi that have the capacity to invade keratinized tissue (skin, hair, and nails) of humans and animals to produce infections called dermatophytosis. In order to review the etiology and epidemiology of dermatophytosis in Goiânia, GO, 1955 specimens with diagnostic suspicion of dermatophytic lesions, were collected from January to December, 1999, from the Mycology Laboratory in the Institute of Tropical Pathology and Public Health, Federal University of Goiás. A total of 445 (22.8%) samples were positive for dermatophytes and Trichophyton rubrum was the most frequently isolated species (49.4%) followed by Trichophyton mentagrophytes (30.8%) and Microsporum canis (12.6%). Concerning the location of the lesions, the inferior limbs, feet and nails together with tinea capitis were the most frequently found clinical pattern in the majority of patients. Correlation between sex, age, location of the lesions and etiologic agents is considered in the study.

Epidemiological and mycological data of onychomycosis in Goiania, Brazil

Onychomycosis defined as fungal infection of the nail represents more than 50% of all onychopathies. Epidemiological studies have shown that this mycosis is worldwide in occurrence, but with geographical variation in distribution. The direct microscopy and culture of the nail samples were performed to identify the causative agent. Out of 2273 patients with nail infection examined between January 2000 and December 2004 in Goiania, state of Goias, Brazil, diagnosis of onychomycosis was confirmed in 1282 cases, with dermatophytes and Candida species being the most common aetiological agents isolated. Dermatophyte onychomycosis was more common in toenails than in fingernails, while onychomycosis caused by yeast had a similar frequency in both toenails and fingernails. Among the species identified, Candida albicans was responsible for 492 cases (38.4%) of onychomycosis, Trichophyton rubrum was found in 327 cases (25.6%) and Trichophyton mentagrophytes in 258 cases (20.1%). Other fungi isolated from nail infections included Aspergillus sp., Trichosporon sp., Geotrichum sp. and Fusarium sp. In our study, yeast of the genus Candida were the dominant cause of onychomycosis in women and dermatophytes were the principal cause of this condition in men.

In vitro susceptibility testing of dermatophytes isolated in Goiania, Brazil, against five antifungal agents by broth microdilution method

The antifungal activities of fluconazole, itraconazole, ketoconazole, terbinafine and griseofulvin were tested by broth microdilution technique, against 60 dermatophytes isolated from nail or skin specimens from Goiania city patients, Brazil. In this study, the microtiter plates were incubated at 28 masculineC allowing a reading of the minimal inhibitory concentration (MIC) after four days of incubation for Trichophyton mentagrophytes and five days for T. rubrum and Microsporum canis. Most of the dermatophytes had uniform patterns of susceptibility to the antifungal agents tested. Low MIC values as 0.03 microg/mL were found for 33.3%, 31.6% and 15% of isolates for itraconazole, ketoconazole and terbinafine, respectively.

Characterization of Cryptococcus neoformans isolated from urban environmental sources in Goiânia, Goiás State, Brazil

Cryptococcus neoformans is an opportunistic fungal pathogen that causes meningoencephalitis as the most frequent clinical presentation in immunocompromised patients, mainly in people infected by HIV. This fungus is an environmental encapsulated yeast, commonly found in soil enriched with avian droppings and plant material. A total of 290 samples of pigeon and the other avian droppings, soil, ornamental trees and vegetable material associated with Eucalyptus trees were collected to study environmental sources of Cryptococcus species in Goiânia, Goiás State. The determination of varieties, serotypes and the susceptibility in vitro to fluconazole, itraconazole and amphotericin B of C. neoformans isolates were performed. C. neoformans var. grubii (serotype A) was found in 20.3% (36/177) of pigeon dropping samples and in 14.3% (5/35) of samples of Eucalyptus. None of the environmental isolates of C. neoformans showed in vitro resistance to three antifungal agents. The knowledge of major route for human cryptococcal infection (inhalation of infectious particles from saprophytic sources) and a total of 60 C. neoformans isolates obtained from AIDS patients with cryptococcal meningitis between October 2001 and April 2002 justify the study of the habitats of these yeasts as probable sources of cryptococcosis in this city.