Influência da quantidade de matriz extracelular na atividade antifúngica de nanopartículas de prata contra biofilmes de espécies de Candida

• Autor(a) principal: Feresin, Leonardo Perina [UNESP]
• Data de Publicação: 2014
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/149636; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2017-01-30/000865968.pdf
• topic: Candidíase bucal; Biofilmes; Candida; Candidiasis, Oral

The aim of the present study was to evaluate the influence of the amont of extracellular matrix on the antifungal activity of silver nanoparticles (SN) against single and mixed biofilms of Candida albicans and Candida glabrata. SN were synthesized by silver nitrate reduction with sodium citrate and stabilized with ammonia. Single and mixed biofilms of Candida species were formed (48 hours) under agitation of 10 and 120 rpm to form lower and higher amounts of extracellular matrix, respectively on the surfaces of acrylic resin specimens inside 24-wells microtiter plates. Then, biofilms were exposed to different concentrations of SN (54 and 108 μg/mL) for 24 h. Chlorhexidine digluconate (CHG) in a concentration of 108 μg/mL was used as positive control. After the treatment period, biofilms were assessed by total biomass quantification (by crystal violet staining) and colony forming units (CFU) enumeration. The structure of Candida biofilms was analyzed by scanning electron microscopy (SEM) images. The results indicated that the amount of extracellular matrix affected the antifungal activity of SN in decreasing total biomass of single and mixed biofilms of oral clinical isolates, with higer reductions for those formed at 10 rpm. Interestingly, the comparisons of different incubation conditions (10 and 120 rpm) at the same SN concentration showed statistical difference (p < 0.05) in the number of CFUs only to reference strain of C. albicans in mixed biofilms treated with SN at 54 μg/mL. By SEM, Candida biofilms treated with SN and CHG revealed structural differences, when compared to the negative control groups. In general, the amount of extracellular matrix affected differently the total biomass and the number of cultivable cells of Candida biofilms. Moreover, given the antifungal effect of SN in decreasing total biomass and number of CFUs...