No abstract

SuMMaryThe gelatinase, urease, lipase, phospholipase and DNase activities of 11 chromoblastomycosis agents constituted by strains of Fonsecaea pedrosoi, F. compacta, Phialophora verrucosa, Cladosporium carrionii, Cladophialophora bantiana and Exophiala jeanselmei were analyzed and compared. All strains presented urease, gelatinase and lipase activity. Phospholipase activity was detected only on five of six strains of F. pedrosoi. DNase activity was not detected on the strains studied. Our results indicate that only phospholipase production, induced by egg yolk substrate, was useful for the differentiation of the taxonomically related species studied, based on their enzymatic profile.

Purpose: The aim of this study was to assess the efficacy of peracetic acid (PAA) for the disinfection of dental acrylic resins experimentally contaminated with Candida albicans, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. Methods: Fifteen materials were used for each type of resin (thermosetting, self-curing and microwave-curing). Each material was placed in a test tube containing culture medium with a suspension of each microorganism and then incubated. The materials were rinsed and transferred to other tubes containing 50 mL of water for 5 min, 0.2% peracetic acid for 5 min or glutaraldehyde for 30 min. The materials were placed in the culture agar and incubated. Microbial growth was determined by colony counting after plating. Results: Candida albicans growth was inhibited by peracetic acid and glutaraldehyde treatments. The number of colonies on resins treated with saline was greater than 10 5 CFU/mL. In resins infected with E. coli, S. aureus and P. aeruginosa the colony growth was not inhibited by saline and peracetic acid, but it was totally inhibited by glutaraldehyde. Conclusion: Surface disinfection using peracetic acid effectively inhibited C. albicans growth on all acrylic resins.

Chromoblastomycosis is a subcutaneous fungal disease caused by dematiaceous fungi, especially by Fonsecaea pedrosoi, regarded as its major causative agent in Brazil. In recent years there has been a decline in the use of skin testing for delayed-type hypersensitivity (DTH) in epidemiological surveys of fungal infections, mainly because of the unpredictability of positive reactions and lack of specificity of the antigens used. The aim of the present study was to assess delayed-type skin tests in guinea pigs experimentally infected with F. pedrosoi using exoantigens prepared from two culture filtrates. Sixteen adult male guinea pigs were inoculated intratesticularly with fungal cells and submitted to sensitivity assays 4 weeks after inoculation. They received an intradermal injection with crude and fractionated antigens from Alviano's and Smith's cultures, and were assessed 24 and 48 h thereafter. Except for one animal, all of them had positive indurations after 48 h. There were no statistical differences between the measurements at 24 and 48 h for each exoantigen used, neither among the induration measurements at 48 h when different preparations were compared. Our results suggest that a delayed-type skin test using antigens produced in synthetic media may be useful for the assessment of primary exposure to chromoblastomycosis.

The lipase activity of nine strains of six chromoblastomycosis agents (Fonsecaea pedrosoi, Phialophora verrucosa, Cladophialophora bantianum, Cladophialophora carrionii, Rhinocladiela aquaspersa and Exophiala jeanselmei) grown on solid medium was investigated using Fourier transform infrared spectroscopy and hierarchical clustering analysis. The data was quantified by p-nitrophenyl palmitate assay using partial least squares (PLS) regression. These methods allowed the correlation of six genera and species within the 1230-1650 and 2800+3000 cm(-1) spectral ranges among strains grown for 14 days from their respective lipolytic activity with RMSEV=0.048 and R2val=0.95 and ten latent variables. The lipolytic activity also was predicted using PLS models with 1230-1650 and 2800-3000 cm(-1) and 900-1450 cm(-1) spectral ranges for strains grown for 21 days. The separate analysis of F. pedrosoi strains yielded a prediction model for biomass at 21 days with RMSEV=0.065 and R2val=0.95 with eight latent variables using (1100-1300)+(1330-1460)+(1550-1650) cm(-1) spectral regions The best model obtained with the clustering of P. verrucosa, C. bantianum, C. carrionii, R. aquaspersa and E. jeanselmei strains was constructed with the same spectral ranges, but with RMSEV=0.074 and R2val=0.94 and ten latent variables. Infrared spectroscopy is suitable for the quantitation of extracellular lipase activity linked to the biomass of chromoblastomycosis agents.

The aim of this study was to develop and characterize antigens for the diagnosis of aspergillosis. Nine strains of Aspergillus species Aspergillus fumigatus , Aspergillus flavus , and Aspergillus niger were grown in Sabouraud and Smith broth to produce exoantigens. The antigens were tested by immunodiffusion against sera from patients with aspergillosis and other systemic mycoses. The protein fraction of the antigens was detected by SDS–PAGE; Western blot and representative bands were assessed by mass spectrometry coupled to a nano Acquity UltraPerformance LC and analyzed by the Mascot search engine. Concurrently, all sera were tested with Platelia Aspergillus EIA. The most reactive antigens to sera from patients infected by A. fumigatus were produced by A. fumigatus MG2 Sabouraud and pooled A. fumigatus Sabouraud samples, both with a sensitivity of 93% and specificity of 100% and 97%, respectively. Aspergillus niger and A. flavus antigens were reactive against A. niger and A. flavus sera, each one with a sensitivity and specificity of 100%. Two proteins, probably responsible for antigenic activity, β-glucosidase in A. fumigatus and α-amylase in A. niger were attained. The commercial kit had a specificity of 22%, sensitivity of 100%, positive predictive value of 48%, and negative predictive value of 100%. The antigens produced showed high sensitivity and specificity and can be exploited for diagnostics of aspergilloma.

Durch Umsetzung von Aminopenicillansäure mit N‐Benzyloxycarbonylaminosäuren in Gegenwart von Dicyclohexylcarbodiimid und folgender Hydrierung wurden die Penicilline (III) rein erhalten.

The development of azole antifungals has allowed for the treatment of several fungal infections. However, the use of these compounds is restricted because of their hepatotoxicity or because they need to be administered together with other drugs in order to prevent resistance to monotherapy. Benzoxazole derivatives are among the most thriving molecular prototypes for the development of antifungal agents. 2-(2'-hydroxyphenyl) benzoxazoles are versatile molecules that emit fluorescence and have antibacterial, antiviral and antifungal properties. 2-(2'-hydroxy-5'-aminophenyl) benzoxazole (HAMBO) was tested against Candida yeast. The inhibition provided by HAMBO was lower than that of fluconazole, showing low antifungal activity against Candida spp., but equivalent to that of benzoxazoles tested in similar studies. HAMBO showed fungistatic activity against all analysed strains. This class of novel benzoxazole compounds may be used as template to produce better antifungal drugs.