Patrícia da Silva Nascente

Essential oil of the leaves of Eugenia uniflora L.: Antioxidant and antimicrobial properties

Essential oil (EO) of the leaves of Eugenia uniflora L. (Brazilian cherry tree) was evaluated for its antioxidant, antibacterial and antifungal properties. The acute toxicity of the EO administered by oral route was also evaluated in mice. The EO exhibited antioxidant activity in the DPPH, ABTS and FRAP assays and reduced lipid peroxidation in the kidney of mice. The EO also showed antimicrobial activity against two important pathogenic bacteria, Staphylococcus aureus and Listeria monocytogenes, and against two fungi of the Candida species, C. lipolytica and C. guilliermondii. Acute administration of the EO by the oral route did not cause lethality or toxicological effects in mice. These findings suggest that the EO of the leaves of E. uniflora may have the potential for use in the pharmaceutical industry.

DROGAS ANTIFÚNGICAS PARA PEQUENOS E GRANDES ANIMAIS

The antifungal drugs are classified in classic and current chemical agents and in antibiotics. The chemists classic agents are those medicines that present in a general way reduced action spectrum against fungi, having a fungistatic effect in an indirect way when modifying the local conditions, as for instance the iodine, acids fat and derived, acid salicilic, tolnaftate and tolciclate. The current chemical agents are represented by imidazole and triazole, flucytosine and allylamines and the antibiotics represented by the polyene (amphotericin B, nystatin and natamycin) and the griseofulvin. The discretion of each antifungal drug will be presented in the work.

Synthesis, antifungal and cytotoxic activities of 2-aryl-3-((piperidin-1-yl)ethyl)thiazolidinones.

A series of sixteen novel thiazolidinone derivatives were synthesized from the efficient one-pot reaction of 2-(piperidin-1-yl)ethylamine, arenealdehydes and mercaptoacetic acid in good yields. Identification and characterization of products were achieved by NMR and GC-MS techniques. The in vitro antifungal activities of all synthesized compounds were evaluated against seven fungi: Candida albicans, Candida parapsilosis, Candida guilliermondii, Cryptococcus laurentii, Geotrichum sp, Trichosporon asahii and Rhodotorula sp. The results are expressed as the Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC) and the best results were found against the Rhodotorula sp yeast. Two thiazolidinones (4h and 4l), MIC and MFC (16.5 μg/mL) proved to be 1.6 times more active than fluconazole and four of them (4b, 4e, 4g and 4k (MIC and MFC 25 μg/mL)) showed similar activity of standard drug to Rhodotorula sp. In addition, the cytotoxicity of thiazolidinones 4a-p was evaluated on cultured Vero cells and most of them displayed low toxicity (above 98 μg/mL). These preliminary and important results could be considered a starting point for the development of new antifungal agents.

Suscetibilidade in vitro de isolados de Sporothrix schenckii frente à terbinafina e itraconazol

The study objective was to determine the in vitro activity of terbinafine and itraconazole through the microdilution technique in broth (NCCLSM27-A2), adapted for dimorphic fungus, in relation to 12 isolates of Sporothrix schenckii. Six were from feline sporotrichosis, three from human sporotrichosis, one from a dog and two from human isolates originating from Instituto Oswaldo Cruz. The inoculum and antifungal concentrates were distributed on microplates that were incubated at 35 degrees C for five days. Minimum inhibitory concentration readings were made at the end of this period. The MIC for terbinafine ranged from 0.055 microg/ml to 0.109 microg/ml, and the MIC for itraconazole ranged from 0.219 microg/ml to 1.75 microg/ml. For both drugs, the MIC from the isolates from IOC was 0.875 microg/ml. The present study demonstrates the high susceptibility of Sporothrix schenckii to terbinafine. Further studies to correlate the in vitro susceptibility tests with the clinical response of patients with sporotrichosis are needed.

An ethnomedicinal survey on phytotherapy with professionals and patients from Basic Care Units in the Brazilian Unified Health System.

ETHNOPHARMACOLOGICAL RELEVANCE In this study, an ethnomedicinal survey was conducted in the city of Pelotas, Brazil, with professionals and patients in the Unified Health System (SUS). With the approval of the National Policy on Medicinal Plants and Herbal Medicines, and with the adoption of a National Policy on Integrative and Complementary Practices in the SUS in Brazil, there is growing concern regarding Brazilian medicinal plants and their proper use in medicine. The expansion of the therapeutic options offered to the users of the SUS includes access to medicinal plants and herbal drugs, as well as related services, such as phytotherapy. For improving health and for the social inclusion of phytotherapies, safety, efficacy, and quality are important strategies. MATERIALS AND METHODS Interviews of both professionals and patients were conducted at five Basic Care Units, and a sample size of 393 was obtained. RESULTS Of the patients attending the Basic Care Units, 91.6% had experienced the use of medicinal plants at least once to treat certain diseases. Of the professionals, 65% had used medicinal plants but only 10% prescribed phytotherapeutics to their patients. Generally, the users were homemakers (26%) of the female gender (71.5%) who were older than 60 years (26%) and had a family income between 1 and 2 Brazilian minimal salaries. The professionals were predominantly female (80%), and a high proportion (80%) believed in the positive effects of phytotherapy (80%), even though these professionals had not been taught phytotherapy as undergraduate students (75%) and had not discussed the topic with their teachers (85%). Patients (81.5%) and professionals (45%) reported that their knowledge of medicinal plants came from their parents or grandparents. From a total of 66 different herbs used by the subjects, mauve (24%) was the most commonly used, often to treat toothaches (24.2%). CONCLUSION It is concluded that a high proportion of users and professionals made use of medicinal plants, and of the large number of plants mentioned in the questionnaire, mauve was the most commonly used, mainly for the treatment of toothaches. The major source of the transmission of knowledge concerning herbal medicine was parents or grandparents.

Occurrency of Malassezia pachydermatis and other infectious agents as cause of external otitis in dogs from Rio Grande do Sul state, Brazil (1996/1997)

The purpose of this work was to evaluate the frequency of Malassezia pachydermatis infection and other infectious agents in dogs with external otitis and with healthy auditory tubes. Clinical manifestations of external otitis were evaluated. Samples from the auditory tube of 102 dogs with otitis and from 32 healthy dogs were submitted to direct microscopic examination and cultured in blood agar and Sabouraud dextrose agar with chloramphenicol and cycloheximide. Direct examination showed more than ten cells of M. pachydermatis in 52.0% of the samples from dogs with otitis, but in only 21.8% of the healthy auditory tube samples. M. pachydermatis was isolated in 37.5% of the samples from dogs with healthy auditory tube and 76.5% (p 0.05). Infection by M. pachydermatis was prevalent in the following breeds: Cocker Spainel, German Shepherd and Brazilian Fila. No differences were found in frequency of the infection in relation to age, sex and ear anatomy of the dogs. Otomycosis were predominantly ceruminous and erythematous. M. pachydermatis was the most frequent agent in external otitis.

Occurrence, isolation and differentiation of Candida spp. and prevalence of variables associated to chronic atrophic candidiasis.

The purpose of this study was to survey the frequency of Candida spp. in patients with chronic atrophic candidiasis (CAC), to differentiate Candida species and to assess the prevalence of certain infection‐associated variables to this disease. Patients with CAC and wearing partial or complete dentures were recruited. Data were obtained by means of a questionnaire with details involving identification of the subject, demographic characteristics, behaviour and medical history, clinical and mycological evaluation and identification of yeast. The sample collection was carried out in the palate or palate and tongue of the subjects using sterilised swabs. Data were submitted to statistical analyses using Fischer’s test. Forty‐three (53%) cases of CAC showed the presence of Candida albicans. Females (75.2%) wearing complete dentures (60.1%) for more than 10 years (58%) were risk factors to CAC development. It could be concluded that: (a) the results did not confirm a significant difference among patients with CAC concerning the presence or absence of Candida spp.; (b) the occurrence of Candida was negatively related to important factors associated to this opportunistic infection; and (c) mycological findings did not indicate that the variables investigated have a significant effect on oral infections by C. albicans or other Candida species.

Evaluation of Malassezia pachydermatis antifungal susceptibility using two different methods

Malassezia pachydermatis is recognized as a normal inhabitant and an opportunistic pathogen of the external ear canal and skin of dogs and cats. In especial clinical conditions, and mainly in the cases of therapeutic failure related to external otitis and dermatitis complicated by this yeast, it is recommended test susceptibility to antifungal drugs. The purpose of this work was to evaluate the susceptibility of 44 isolates of M. pachydermatis from the external ear canal and skin of dogs and cats using two different in vitro antifungal susceptibility methods: the Etest® and the broth microdilution method. Thirty-five samples were tested using the Etest®, twenty-four samples were tested using the broth microdilution method and fifteen samples were tested using both tests. The antifungal agents used were ketoconazole (KTZ), fluconazole (FLZ) and itraconazole (ITZ). In the broth microdilution method the yeast was less susceptible to ITZ while KTZ had the strongest activity. On the other hand, the Etest® showed that M. pachydermatis was more susceptible to ITZ while the less active drug was FLZ. The simultaneous evaluation using both methods identified FLZ as the antifungal drug with the highest activity (64.3%), followed by KTZ (57.1%) and ITZ (28.6%). These results showed that there is an urgent need to standardize of the values considered as parameters for growth inhibition of this yeast so a simple and efficient method can be used routinely in the laboratory practice.

Ocorrência de Cryptococcus neoformans em excretas de pombos na cidade de Pelotas, Estado do Rio Grande do Sul

INTRODUCTION Cryptococcus neoformans is an encapsulated yeast and is the etiological agent for human and animal cryptococcosis. It is found in sources within the environment, including pigeon excrement, and is an important cause of mortality among immunocompromised individuals worldwide. METHODS Seventy different environments in the city of Pelotas, Rio Grande do Sul, were surveyed for the purpose of investigating Cryptococcus neoformans occurrences in pigeon excreta. The environments included buildings, public squares and outdoor locations in the city. After collection, chloramphenicol saline solution was added to the excreta, which were then homogenized and seeded onto Sabouraud agar with chloramphenicol and onto Niger agar, and incubated at 32 degrees C. Identification was performed by direct examination and by means of the phenoloxidase and urease tests, carbohydrate assimilation and culturing in CGB medium. RESULTS Out of the sites investigated (n = 70), 26 (37.1%) of them contained pigeon excreta. These included historical buildings (n = 8), a church tower (n = 1), rice mills and warehouses (n = 7), a public square (n = 1) and outdoor locations (n = 9). Cryptococcus neoformans was isolated from 26.9% (n = 7/26) of these locations. CONCLUSIONS This study draws attention to isolation of this fungus in urban areas that present large accumulations of pigeon excrement. This represents a risk to public health, especially for immunocompromised individuals.

Fungal ovicidal activity on Toxocara canis eggs

BACKGROUND Visceral toxocariasis is a parasitic zoonosis caused by Toxocara canis. The prevalence of this parasite in dogs, soil contamination and the resistance of eggs increase human exposure to the disease. Moreover, the difficulties of the control measures justify the need for alternative ones. AIMS The objective of this study was to evaluate the in vitro ovicidal activity of fungi isolated from soils from public places in the city of Pelotas, Rio Grande do Sul, Brazil, on Toxocara canis. METHODS Samples of soil from ten localities were inoculated onto Petri dishes with 2% water-agar (WA) that contained antibiotics, and incubated at 25°C/21 days. Isolated fungi were tested in vitro for ovicidal activity, with five replicates. One mL of an embryonated Toxocara canis egg suspension (10(3) eggs) was poured over the fungal cultures after 10 days of growth. At intervals of 7, 14 and 21 days, 100 eggs were removed from each plaque and evaluated by optical microscopy. RESULTS Acremonium, Aspergillus, Bipolaris, Fusarium, Gliocladium, Mucor and Trichoderma were isolated from the soil. A significant ovicidal type 3 effect was observed in Trichoderma, Fusarium solani complex and Acremonium. Those isolates from the genus Trichoderma showed their ovicidal effect on the 14th day of fungus-egg interaction. The other fungal genera tested showed a type 2 effect. CONCLUSIONS These results suggest that the use of Trichoderma and Fusarium solani complex in biological control of T. canis is promising; however, further studies should be performed.