Francisco Afrânio Cunha

Airborne fungi isolated from Fortaleza City, State of Ceara, Brazil

Airbone fungi are considered important causes of allergic rhinitis and allergic asthma. The knowledge of these fungi in a city or region is important for the ecological diagnosis and specific treatment of allergic manifestations induced by inhalation of fungal allergens. The airborne fungi of Fortaleza, State of Ceará, Brazil, were studied during a one year period. Five hundred and twenty Petri dishes with Sabouraud dextrose agar medium were exposed at ten different locations in the city. The dishes exposed yielded one thousand and five hundred and twenty one colonies of twenty four genera. The most predominants were: Aspergillus (44.7%), Penicillium (13.3%), Curvularia (9.8%), Cladosporium (6.8%), Mycelia sterilia (6.0%), Fusarium (3.5%), Rhizopus (3.1%), Drechslera (2.6%), Alternaria (2.4%) and Absidia (2.2%). The results shown that Aspergillus, Penicillium, Mycelia sterilia, Fusarium and Alternaria were found during all months in the year. Absidia was more frequent during the dry season. Anemophilous fungi and the high concentration of spores in the air are important because may result in an increased number of people with allergic respiratory disease.

Antifungal activity and mode of action of carvacrol against Candida albicans strains

In this study, the minimal inhibitory concentration (MIC), minimal fungicidal concentration (MFC) and mode of action of carvacrol were determined. MIC was determined according to the standard broth microdilution method, and MFC was taken as the lowest concentration in culture plates with Sabouraud dextrose agar, at which growth was less than 3 CFU. The effect of ergosterol or sorbitol on carvacrol was investigated using the broth microdilution method. MIC was 256 μg/mL and MFC was 512 μg/mL. This phytoconstituent acts by binding to sterols in the fungal membrane and does not act by modifying the fungal cell wall. This study is important because it shows the mode of action of carvacrol. However, more studies are necessary to define the exact mechanism of action.

ANTIFUNGAL ACTIVITY OF SILVER NANOPARTICLES OBTAINED BY GREEN SYNTHESIS

Silver nanoparticles (AgNPs) are metal structures at the nanoscale. AgNPs have exhibited antimicrobial activities against fungi and bacteria; however synthesis of AgNPs can generate toxic waste during the reaction process. Accordingly, new routes using non-toxic compounds have been researched. The proposal of the present study was to synthesize AgNPs using ribose as a reducing agent and sodium dodecyl sulfate (SDS) as a stabilizer. The antifungal activity of these particles against C. albicans and C. tropicalis was also evaluated. Stable nanoparticles 12.5 ± 4.9 nm (mean ± SD) in size were obtained, which showed high activity against Candida spp. and could represent an alternative for fungal infection treatment.

Freqüência e percentual de suscetibilidade de bactérias isoladas em pacientes atendidos na unidade de terapia intensiva do Hospital Geral de Fortaleza

INTRODUCTION: Nosocomial infections are prominent problem in hospital environment, mainly in intensive care units (ICU), where innumerous factors favoring the development of these infections are found. Objectives: To determine the frequency and the antibiotic resistance pattern of bacteria isolated from ICU patients in the General Hospital of Fortaleza (HGF). MATERIAL AND METHODS: Bacteria were isolated in culture medium and the identification and test of susceptibility to antimicrobials was performed using MicroScan WalkWay automation device. RESULTS: From January to December of 2002, 34% of specimens from tracheal secretion; 10% from catheter cultures; 26% from urine and 30% from the blood yielded isolates. Specimens more frequent in tracheal secretion were Pseudomonas aeruginosa (16%) e Klebsiella pneumoniae (15%). In catheter cultures, we found high prevalence of Staphylococcus negative coagulase (SNC) (25%) and Staphylococcus aureus (25%); in urine, Klebsiella pneumoniae (16%) and Pseudomonas aeruginosa (14%) were the most prevalent. From blood, we isolated mostly SNC (41%) and Staphylococcus aureus (17%). About antimicrobial susceptibility patterns of Pseudomonas aeruginosa isolated from tracheal secretion, we found a high sensitivity to piperacilin and high resistance to ceftriaxone and cefotaxime. Klebsiella pneumoniae isolated fom tracheal secretion showed high sensibility to imipenem, but no resistance to other antimicrobials althogeter. Susceptibility to ceftazidime was 54%. Isolates from catheters showed broad resistance pattern (ampicillin/sulbactam, cefepime, cefotaxime, ceftazidime, ceftriaxone, cefuroxime, gentamicin, piperacillin/tazobactam, piperacillin, ticarcillin/clavulani acid and tobramycin) but imipenem susceptibility. In urine, the susceptibility to ciprofloxacin was 55%. Staphylococcus aureus e SNC were isolated mainly from catheter, with high susceptibility to vancomycin (100%). DISCUSSION: Antibiotic resistance is an increasing problem challenging ICUs worldwide. Infections due to multiresistant bacteria correlate with increased morbidity and mortality in severely ill patients. Conclusion: The most important pathogens causing infections in ICU of HGF were P. aeruginosa. K. pneumoniae, Acinetobacter baumannii, S. aureus and SNC.

Antifungal resistance of Candida tropicalis isolated in the State of Ceará

In this study, the resistance to antifungal drugs was investigated among 51 strains of Candida tropicalis isolated from clinical samples in the State of Ceará, Brazil. Antifungal resistance was a rare finding in our study and was restricted to three (5.9%) of the strains of Candida tropicalis. These exhibited resistance to both fluconazole and itraconazole.

Frequency and enzymatic activity of Candida albicans isolated from the oral cavity of HIV-positive patients at Fortaleza, Ceará

Candida albicans and other species are usually involved in opportunistic infections in patients with acquired immunological deficiency syndrome (AIDS). The virulence mechanisms by which this yeast expresses its pathogenicity include adherence patterns, ability to form pseudomycelia and production of extracellular enzymes, among others. The objective of this research was to verify the frequency of Candida and the production of proteinase and phospholipase in 52 strains of Candida albicans from the oral cavity of patients infected by HIV treated at Hospital Sao Jose, AIDS reference and training center in Fortaleza, Ceara. Samples were collected of patients, with or without oral lesions characteristic of candidosis. From 100 patients, 80% presented positivity for Candida: 65% (52) were identified as C. albicans, 27.5% (22) as C. tropicalis, 2.5% (2) as C. glabrata, 2.5% (2) as C. krusei and 2.5% (2) as C. guilliermondii. Among the strains of C. albicans isolated from the oral cavity, proteinase and phospholipase were detected in 69.2% and 73%, respectively. The results suggested that C. albicans was the most frequent species observed, with intermediate expression of proteinase and phospholipase.

Anti-Candida albicans effectiveness of citral and investigation of mode of action.

Context: Candidiasis is a mycosis caused by Candida species, which is of clinical importance due to the increase in resistant yeasts. Candida infection has been a serious health problem due to the inappropriate use of antibiotics. Therefore, it is necessary to study molecules with an antifungal action. Citral is a monoterpene with known pharmacological properties, including antimicrobial action. Objective: The aim of this work was to determine the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of citral and the probable mode of action. Materials and methods: The MIC of citral was determined by the broth microdilution method using Sabouraud dextrose medium. Additionally, the interference of citral in cell wall (sorbitol assay) and the binding of citral to ergosterol and cholesterol were studied, carried out by broth microdilution method. Results: The MIC and MFC of citral were 512 and 1024 µg/mL, respectively. The MIC of amphotericin B was 1 µg/mL. The mechanism of action did not involve either the cell wall or ergosterol. However, the presence of cholesterol increased the MIC of citral to 1024 µg/mL, indicating there is some interaction between citral and cholesterol. Amphotericin B was used as the positive control, and it showed a high MIC in the presence of ergosterol (32 µg/mL), while in the presence of cholesterol MIC increased to 4 µg/mL. Conclusion: Citral inhibits the growth of C. albicans. The probable mechanism of action did not involve the cell wall or ergosterol. Citral is able to interact with cholesterol. More studies are necessary to describe their effects completely.

Freqüência e atividade enzimática de Candida albicans isoladas da mucosa bucal de crianças de uma creche da prefeitura de Fortaleza

As candidiases bucais (tambem chamadas sapinhos) que ocorrem em criancas sao causadas por uma deficiencia imunologica, bem como por outros fatores tais como ma higiene bucal e esterilizacao inadequada dos utensilios utilizados pelas mesmas, que potencializam a ocorrencia dessa infeccao fungica. Considerando esse fato, foram avaliadas a frequencia e a atividade enzimatica de Candida sp. isoladas em criancas de uma creche publica (Aprisco) na cidade de Fortaleza, Ceara. Foram coletadas amostras da mucosa bucal de 364 alunos de 1 a 5 anos de idade. Elas foram semeadas em agar Sabouraud dextrose com cloranfenicol, incubadas por 72 horas a 37oC e identificadas por testes micologicos. Verificou-se que 67 (18%) apresentaram leveduras do genero Candida. A Candida albicans foi a mais frequente, com 30 isolados (45%), seguida pelas C. tropicalis (31%), C. guilliermondii (17%), C. glabrata (4,5%) e C. stellatoidea (1,5%). Com relacao as atividades enzimaticas das cepas de Candida albicans, 20% produziram a enzima proteinase e 33%, a fosfolipase. As Candida albicans isoladas da mucosa bucal de criancas dessa creche da prefeitura apresentaram uma fraca atividade enzimatica. Assim, conclui-se que essas cepas parecem ter uma baixa virulencia.

Airborne fungi causing respiratory allergy in patients from Fortaleza, Ceará, Brazil

Os fungos anemofilos estao dispersos no ar atmosferico. O conhecimento dos fungos anemofilos em uma cidade e importante para o diagnostico ecologico e o tratamento especifico de manifestacoes alergicas induzidas pela inalacao de alergenos. Os fungos alergenicos sao usados para o diagnostico e o tratamento da alergia em todo o mundo, o que provavelmente persistira por muitos anos ainda. O objetivo deste trabalho foi fazer uma relacao entre os fungos anemofilos e a alergia respiratoria (asma e rinite) de pacientes da cidade de Fortaleza, Ceara. Primeiro foi feita uma pesquisa dos fungos alergenicos dispersos no ar atmosferico da cidade de Fortaleza. Os extratos fungicos alergenicos foram feitos a partir dos dez bolores mais predominantes do ar de Fortaleza, usando bicarbonato de sodio. Foram feitos testes da puntura em cinquenta pacientes com alergia respiratoria (asma e rinite) e dez pessoas saudaveis (sem alergia respiratoria). O teste positivo foi feito com histamina e o teste negativo com uma preparacao de bicarbonato de sodio. Os fungos predominantes no ar da cidade de Fortaleza foram: Aspergillus, Penicillium, Curvularia, Cladosporium, Mycelia sterilia, Fusarium, Rhizopus, Drechslera, Absidia e Alternaria. Como demonstrado pelo teste da puntura: tres extratos fungicos (Aspergillus, Alternaria e Drechslera) foram positivos em todos os pacientes; dois (Penicillium e Curvularia) foram positivos em trinta e cinco pacientes; dois (Cladosporium e Mycelia sterilia) foram positivos em trinta pacientes; e tres (Rhizopus, Absidia e Fusarium) foram positivos em nove pacientes. Todos os testes controles foram negativos. Todos os dez fungos anemofilos mais predominantes isolados no ar podem provocar reacoes nos testes cutâneos em individuos com alergia respiratoria na cidade de Fortaleza.

Cryptococcus neoformans causing meningitis in AIDS patients

Cryptococcus neoformans causes meningitis in AIDS patients. In the São José Hospital, reference center for patients with AIDS in Fortaleza--Ceará State--Brazil, 54 samples of the cerebrospinal fluid were analyzed from January 1st through December 31st 2000. Direct examination with India ink and culture in Sabourauds agar at 37 degrees C were done. Of the specimens studied 5(9.25%) were positive.