Xisto Sena Passos

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.

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.

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.

Antifungal susceptibilities of clinical and environmental isolates of Cryptococcus neoformans in goiânia city, Goiás, Brasil

We evaluated the antifungal activities of amphotericin B, fluconazole, itraconazole and voriconazole in 70 Cryptococcus neoformans strains obtained from cerebrospinal fluid from AIDS patients and 40 C. neoformans strains isolated from the environment. Four clinical isolates were identified as C. neoformans var. gattii. The susceptibility test was done using a broth microdilution method according to NCCLS M27-A2. Range minimal inhibitory concentrations (MICs) for C. neoformans clinical isolates were 0.06-1.0 microg/mL for amphotericin B, 0.125-8 microg/mL for fluconazole, 0.03-0.5 microg/mL for itraconazole and 0.03-0.25 microg/mL for voriconazole. C. neoformans environmental isolates showed range MICs 0.015-0.125 microg/mL, 0.25-2.0 microg/mL, 0.007-0.125 microg/mL and 0.03-0.25 microg/mL for amphotericin B, fluconazole, itraconazole and voriconazole respectively. The MICs results obtained from clinical and environmental isolates showed similar pattern of susceptibility and no resistance has been found in our isolates.

Asymptomatic oral carriage of Candida species in HIV-infected patients in the highly active antiretroviral therapy era

Oropharyngeal candidiasis is the most common opportunistic fungal infection in individuals infected with human immunodeficiency virus. CD4+ lymphocytes count and the quantification of viral RNA in blood plasma have been found to be the main markers of HIV disease progression. The present study was conducted to evaluate Candida sp. diversity in the oral cavity of HIV-infected patients and to determine whether there was association of CD4+ cell count and viral load with asymptomatic oral Candida carriage. Out of 99 HIV-positive patients studied, 62 (62.6%) had positive culture for Candida (oral carriage) and 37 patients (37.4%) had Candida negative culture (no oral carriage). The etiologic agents most common were C. albicans and C. tropicalis. The range of CD4+ was 6-2305 cells/mm3 in colonized patients and 3-839 cells/mm3 for non-colonized patients, while the viral load was 60-90016 copies/mL for colonized patients and 75-110488 copies/mL for non colonized patients. The viral load was undetectable in 15 colonized patients and in 12 non colonized patients. Our results showed that there was no significant difference of the variables CD4+ cell count and viral load between oral candida carriage and no oral candida carriage patients.

Antifungal activity of Ocimum gratissimum towards dermatophytes

The development of more effective and less toxic antifungal agents is required for the treatment of dermatophytosis. Plants and their preparations have been used as medicines against infectious diseases. Extracts of Ocimum gratissimum leaves were investigated for in vitro antifungal activity, using agar dilution technique against dermatophytes. The extracts (hexane, chloroform fractions, the essential oil and eugenol) produced antifungal activities against Microsporum canis, M. gypseum, Trichophyton rubrum and T. mentagrophytes. Trichophyton rubrum, the most common aetiological agent of dermatophytosis in Goiânia, state of Goiás, Brazil, was also the most susceptible dermatophyte. The hexane fraction and eugenol were the most active. Hexane fraction inhibited the growth of 100% of dermatophytes at a concentration of 125 μg ml−1, while eugenol inhibited the growth of 80% of dermatophytes at this same concentration. These results show that extracts of O. gratissimum are active in vitro against human pathogenic dermatophytes.

Atividade antifúngica de Caryocar brasiliensis (Caryocaraceae) sobre Cryptococcus neoformans

The widespread occurrence of cryptococcosis mainly in immunocompromised patients and the side effects of available drugs which are effective against this mycosis have led investigators to search for new antimycotic agents. Caryocar brasiliensis derived compounds were investigated against Cryptococcus neoformans using the agar dilution method. Based on MIC values, the best results were obtained with a concentration of < 250 g/mL of cuticular waxes of the Caryocar brasiliensis leaf collected during the dry period (170.8mm of precipitation) which inhibited the growth of 91.3% (21/23) Cryptococcus neoformans isolates.

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.

Influence of fruit biotypes on the chemical composition and antifungal activity of the essential oils of eugenia uniflora leaves

A analise multivariada da composicao quimica dos oleos essenciais das folhas de Eugenia uniflora com diferentes cores de fruto indicou a presenca de tres grupos de oleos em relacao ao biotipo do fruto das amostras. O primeiro grupo incluiu amostras de frutos amarelos, vermelhos escuros e roxos contendo altas percentagens de germacreno B (11,1-30,7%), germacrona (9,8-54%) e atractilona (0-19,9%). No grupo II, com amostras de frutos vermelhos claro, os constituintes majoritarios foram o curzereno (42,0-43,2%), germacreno D (8,7-9,0%) e germacreno A (5,9-8,9%), enquanto que o grupo III incluiu amostras com frutos vermelho-alaranjado, caracterizadas por um alto conteudo de selina-1,3,7(11)-trien-8-ona (40,3-55,4%) e epoxido de selina-1,3,7(11)-trien8-ona (12,7-24,4%). Os oleos essenciais foram investigados frente ao fungo Paracoccidioides brasiliensis pela tecnica de macrodiluicao em caldo. O resultado mais significativo foi obtido com o oleo do grupo II, com a forma leveduriforme de P. brasiliensis sendo inibida completamente na concentracao de 62,5 mg mL -1 . The multivariate chemical analysis of essential oils of Eugenia uniflora leaves with different fruit colours indicated the presence of three oil clusters regarding sample biotypes. The first cluster included yellowish, dark red and purple fruits with high percentages of germacrene B (11.1-30.7%), germacrone (9.8-54%) and atractylone (0-19.9%). In cluster II, with bright red fruit samples, the major constituents were curzerene (42.0-43.2%), germacrene D (8.7-9.0%) and germacrene A (5.9-8.9%), whereas cluster III included red-orange fruit samples containing high contents of selina-1,3,7(11)-trien-8-one (40.3-55.4%) and selina-1,3,7(11)-trien-8-one epoxide (12.7-24.4%). The clustered oils were investigated against the systemic fungus Paracoccidioides brasiliensis via the broth macrodilution method. The oil from cluster II revealed the most significant result. The yeast form of P. brasiliensis was completely inhibited at a concentration of 62.5 mg mL -1