Gladis Aver Ribeiro

Cutaneous pythiosis in horses from Brazil.

Summary. Equine pythiosis was studied in five animals from two farms located in a swampy region of southern Brazil (Rio Grande do Sul State). Granulomatous lesions exuding necrotic material and containing a central yellow and firm tissue core, the ‘kunker’, were observed on the top of the nose of one horse, on the abdomen of two horses and on the hind limbs of two other animals. Direct microscopic preparations, histo‐pathological examination of lesion material, and macroscopic and microscopic characteristics of the isolates confirmed the diagnosis of pythiosis. Surgical intervention of the inflammatory processes, intravenous potassium iodide and topical appiication of copper sulphate were used without success.

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.

Antimicrobial activity of ethanol extracts of Agaricus brasiliensis against mutans streptococci

This study evaluated the antimicrobial activity of three different ethanol extracts of Agaricus brasiliensis S. Wasser et al. (Agaricaceae) on the growth and cell adherence of mutans streptococci. Crude ethanol extracts (100% EtOH, 75% EtOH, and 50% EtOH, v/v) obtained from dried basidiomes of A. brasiliensis were assessed against Streptococcus mutans UA159 and Streptococcus sobrinus 6715 by the agar diffusion method, determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), and inhibition of cell adherence to a glass surface. In the agar diffusion method, only the 100% ethanol extract revealed inhibition of bacterial growth. Yet, in MIC and MBC tests, the three extracts presented antimicrobial properties and MIC and MBC values between 87.4 and 444.5 μg mL−1. The MBC was predominantly similar to MIC against S. mutans, but only the 75% ethanol extract was bactericidal against S. sobrinus. Among the ethanol extracts tested, the 100% ethanol extract was the most active (MIC 87.4 μg mL−1). The cellular adherence also was inhibited at concentrations from 100 to 400 μg mL−1 of 50% and 75% ethanol extracts. These results provide promising baseline formation for the potential use of A. brasiliensis against mutans streptococci. These findings warrant more in-depth studies of the active principles of this mushroom ethanol extract.

Potential allelopathic and antibacterial activity from Alternanthera philoxeroides

Alternanthera philoxeroides is a promising species in the search for new molecules with biological effects. To accelerate this bioprospection process of A. philoxeroides, the chosen methods (allelopathy and discdiffusion technique) are excellent alternatives. The purpose of this study was to evaluate the allelopathic effects and verify the antibacterial properties of extracts from A. philoxeroides. To evaluate the antibacterial activity, disc diffusion technique was used with five reference strains. The germination test was conducted with the extracts at concentrations of 0, 1.0, 2.0 e 3.0 mg mL-1 in a petri dish with 30 lettuce seeds and for the growth trial 10 seeds were used. The experimental design was completely randomized in factorial 4 × 2 × 4 (four extracts, two sources, four concentrations), with four replicates.The results indicate that the lettuce germination was influenced by ethyl acetate fraction obtained from leaves of A. philoxeroides at the highest concentrations; however, the germination speed and the radicle growth were significantly affected by all the extracts starting at 1mg mL-1 concentration. Those results demonstrate allopathic effect of different extracts of this plant, although they have not interfered with the strains growth used in this experiment.