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- ItemAcesso aberto (Open Access)Antifungal susceptibility testing of yeast isolated from corneal infections(Conselho Brasileiro de Oftalmologia, 2003-10-01) Mascaro, Vera Lucia Degaspare Monte [UNIFESP]; Hofling-Lima, Ana Luisa [UNIFESP]; Gompertz, Olga Fischman [UNIFESP]; Yu, Maria Cecília Zorat [UNIFESP]; Matta, Daniel Archimedes da [UNIFESP]; Colombo, Arnaldo Lopes [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Hospital do Servidor Público Estadual Cornea SectorPURPOSE: To report the antifungal susceptibility profile of yeast isolates obtained from cases of keratitis. METHODS: Susceptibility testing of 15 yeast strains isolated from corneal infections to amphotericin B, fluconazole, itraconazole and ketoconazole was performed using the NCCLS broth microdilution assay. RESULTS: Most episodes of eye infections were caused by Candida albicans. The antifungal drugs tested showed the following minimal inhibitory concentration values against yeast isolates: 0.125-0.5 µg/ml for amphotericin B; 0.125->64.0 µg/ml for fluconazole; 0.015-1.0 µg/ml for itraconazole and 0.015-0.125 µg/ml for ketoconazole. Despite the fact that all Candida isolates were judged to be susceptible to azoles, one isolate showed a minimal inhibitory concentration value significantly higher than a 90% minimal inhibitory concentration of all tested isolates. Rhodotorula rubra was resistant to fluconazole and itraconazole. CONCLUSIONS: Despite the fact that most yeast isolates from corneal infections are usually susceptible to amphotericin B and azoles, they exhibit a wide range of minimal inhibitory concentration values for antifungal drugs. The identification of strains at species level and their susceptibility pattern to antifungal drugs should be considered before determining the concentration to be used in topical antifungal formulations in order to optimize therapeutic response in eye infections.
- ItemAcesso aberto (Open Access)Caracterização da produção de biofilme por isolados de Aspergillus spp. e o seu impacto biológico(Universidade Federal de São Paulo (UNIFESP), 2017-03-15) Trindade, Mario Roberto de Sousa [UNIFESP]; Colombo, Arnaldo Lopes [UNIFESP]; Gonçalves, Sarah Santos [UNIFESP]; http://lattes.cnpq.br/1018708169217296; http://lattes.cnpq.br/4512261018429681; http://lattes.cnpq.br/2416431642602733; Universidade Federal de São Paulo (UNIFESP)In the last decade, the biomedical literature has described that Aspergillus spp. isolates are able to grow adhered to biotic and abiotic surfaces, surrounded by a polysaccharide extracellular matrix that provides protection from physical and chemical agents, such as the immune system and antifungal drugs. This study aims to characterize the biofilm formation by 18 isolates of Aspergillus section Flavi and section Fumigati, also to evaluate its impact in the antifungal susceptibility “in vitro” and in the virulence. The identification of Aspergillus spp. isolates was realized through a polyphasic approach, including phenotypic tests and molecular identification. The in vitro susceptibility profile was evaluated using the broth microdilution method (CLSI, document M38-A2). The biofilm formed by isolates of Aspergillus spp. was quantified using the crystal violet technique and the impact of this biofilm in the antifungals activity was evaluated by the XTT tetrazolium salt. Isolates with higher biofilm formation capacity were selected for micromorphological characterization by confocal microscopy before and after treatment with amphotericin B and voriconazole. The virulence of the strains with higher and lower biofilm formation capacity were evaluated using the experimental model of infection in Galleria mellonella, generating a survival curve. The identification using a polyphasic approach, allowed the accurate identification of all 18 isolates, namely: six A. tamarii, six A. flavus and six A. fumigatus. All isolates presented MIC values against the antifungals tested in accordance to data described in the literature. The A. fumigatus isolates produced more biofilm than A. tamarii and A. Flavus isolates, with no difference between the later two. Biofilm cells from all isolates of Aspergillus spp. were resistant to triazoles and presented varied susceptibility to amphoterin B. The confocal microscopy analyses demonstrated that the biofilm is composed of well delineated and metabolically active hyphae, however, this aspect was greatly altered after exposure to antifungals. Using the G. mellonella invertebrate model, we observed that all isolates were capable of 100% mortality, in 24 hours for invertebrates infected with A. tamarii and A. flavus and in 96 hours for invertebrates infected with A. fumigatus. The high biofilm-forming phenotype did not affect the survival of the invertebrates Our results demonstrate that the antifungals tested have some level of action on the biofilm formed by Aspergillus spp. even at concentrations lower than the MIC value for these isolates. It was not possible to establish a relationship between the biofilm formation capacity and the survival time.
- ItemAcesso aberto (Open Access)Clinical treatment of corneal infection due to Fonsecaea pedrosoi: case report(Conselho Brasileiro de Oftalmologia, 2005-04-01) Hofling-Lima, Ana Luisa [UNIFESP]; Guarro, Josep; Freitas, Denise de [UNIFESP]; Godoy, Patricio [UNIFESP]; Gené, Josepa [UNIFESP]; Souza, Luciene Barbosa de [UNIFESP]; Zaror, Luis; Romano, Andre C. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universitat Rovira I Virgili Facultat de Medicina I Ciencies de la Salut; University Austral de Chile Microbiology Unitat ClinicTo report an unusual case of fungus keratitis due to Fonsecaea pedrosoi that developed after corneal trauma. Case report: A 18-year-old male presented with a corneal ulcer in the right eye, 28 days after a trauma with glass fragments. Corneal scrapings were collected for smears and culture. Dematiaceous hyphae were seen on wet mounts of the scrapings and dark pigmented colonies grew repetitively on the culture media; all colonies were identical, and were subsequently identified as Fonsecaea pedrosoi. Treatment was initiated with topical natamycin at one hour intervals, 200 mg oral ketoconazole per day and later changed to a combination of 200 mg ketoconazole and amphotericin B. In humid tropical regions Fonsecaea pedrosoi is one of the primary causes of human chronic cutaneous mycosis, chromoblastomycosis. Combination of systemic and topical antifungal medications may provide the best option for cure in corneal chromoblastomycosis.
- ItemAcesso aberto (Open Access)Contaminação de halos doadores córneo-esclerais em ceratoplastia penetrante no Hospital de Clínicas de Porto Alegre(Conselho Brasileiro de Oftalmologia, 2008-02-01) Borowsky, Cláudia Martins; Wallau, Anelise Dutra [UNIFESP]; Reetz, Aline; Kwitko, Sérgio [UNIFESP]; Rymer, Samuel; Locatelli, Claudete Inês; Universidade Federal do Rio Grande do Sul Hospital de Clínicas de Porto Alegre; Universidade Federal de São Paulo (UNIFESP); Universidade de Passo Fundo; Hospital de Clínicas de Porto Alegre; UFRGS Faculdade de Medicina; UFRGS Hospital de Clínicas de Porto Alegre; UFRGSPURPOSE: To determine the incidence of positive corneoscleral rim cultures preserved in Optisol GS medium, to identify pathogens involved and possible recipient eye infection. METHODS: A hundred sixty-three corneoscleral rim cultures penetrating keratoplasties performed from January 2001 to January 2003 in the Hospital de Clínicas de Porto Alegre were reviewed. Enucleations and corneal storage were done as aseptic as possible and gentamicin 0.3% was instilled. Corneoscleral rim was divided into two segments, half was inoculated into Sabouraud broth and the other half into thioglycolate broth; inoculation into blood agar, chocolate agar and MacConkey agar was done later if necessary for pathogen identification. The receiver's eye data were reviewed. RESULTS: There were eleven positive cultures (6.7%) out of 163 evaluated corneoscleral rim cultures. Of these, four were Staphylococcus epidermidis, one was Staphylococcus aureus, one was Serratia sp., one was Pseudomonas aeruginosa and the other four were different subtypes of Candida (two Candida sp., one Candida albicans and one Candida parapapilosis). All pathogens were resistant to gentamicin. None of the eleven cases of positive corneoscleral rim cultures resulted in ocular infection at the receiver's eyes (six months follow-up). CONCLUSIONS: We found low rates of positive corneoscleral rim cultures after penetrating keratoplasty at the Porto Alegre Clinical Hospital. The most frequent involved pathogens were Staphylococcus sp and Candida sp. Although we did not identify any postoperative infection at the receiver's eyes, we recommend corneoscleral rim culture for guidance of postoperative infection, a rare but possible devastating ocular event.
- ItemAcesso aberto (Open Access)Effect of topical 0.5% povidone-iodine compared to 5% natamycin in fungal keratitis caused by Fusarium solani in a rabbit model: a pilot study(Conselho Brasileiro de Oftalmologia, 2008-12-01) Oliveira, Lauro Augusto De [UNIFESP]; Takata, Thales Takeo [UNIFESP]; Shiguematsu, Alvio Isao [UNIFESP]; Melo Júnior, Luiz Alberto Soares [UNIFESP]; Gompertz, Olga Fischman [UNIFESP]; Sousa, Luciene Barbosa De [UNIFESP]; Mannis, Mark J.; Universidade Federal de São Paulo (UNIFESP); University of CaliforniaPURPOSE: To evaluate the efficacy of topical administration of 0.5% povidone-iodine in experimental Fusarium solani keratitis in rabbits. METHODS: Fungal keratitis caused by Fusarium solani was induced in the right eye of 24 New Zealand rabbits. The rabbits were randomly divided into 3 different treatment groups: Group I (povidone-iodine) - treated with topical 0.5% povidone-iodine; Group II (natamycin) - treated with topical 5% natamycin; and Group III (control) - treated with topical saline solution. In all groups the rabbits were treated for three days and then sacrificed. The corneas were excised, macerated and immersed in 10 mL BHI. Culture samples were plated daily on Sabouraud's agar for 7 days, and the number of colony-forming units (CFU) was counted. The rabbits were clinically evaluated during the treatment period. RESULTS: The povidone-iodine and natamycin groups demonstrated better efficacy than the control group based on the number of rabbits with no colonies growing. However, there were no statistically significant differences between the three groups when the number of CFU was analyzed (p>0.05). CONCLUSIONS: Our study demonstrates important methodological considerations in the use of in vivo animal models for the testing of antifungal agents. Using this sample size and methodology of counting CFU, topical 0.5% povidone-iodine demonstrated no benefit in the treatment of experimental Fusarium solani when compared with topical 5% natamycin.
- ItemAcesso aberto (Open Access)Use of oral voriconazole as adjunctive treatment of severe cornea fungal infection: case report(Conselho Brasileiro de Oftalmologia, 2006-06-01) Freda, Roberto [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Hospital Banco de Olhos de Porto Alegre Setor de Córnea e Doenças ExternasA case of Aspergillus flavus keratitis was successfully treated with oral voriconazole and penetrating keratoplasty after conventional antifungal medical therapy failure.