Microbial Biosystems Journal (Jun 2017)
Antibiofilm activity of Streptomyces toxytricini Fz94 against Candida albicans ATCC 10231
Abstract
Candida albicans is a significant cause of morbidity and mortality inimmunocompromised patients worldwide. Biofilm formation by Candida species is a significantvirulence factor for disease pathogenesis. Keeping in view the importance of Streptomyces'metabolites, the present study was initiated during the bioprospecting programme of EgyptianStreptomyces carried by the authors since 2013. Native Streptomyces isolates were recoveredfrom soil samples collected from different governorates. Antifungal activity of forty isolates ofStreptomyces were performed against planktonic (free cells) of C. albicans ATCC 10231 andresistant clinical Candida isolates. Streptomyces isolates showed high inhibition activity againstfree cells of Candida were further assayed against biofilm of C. albicans reference strain. Themost active Streptomyces sp. (no.6) was identified phenotypically, biochemically and by using16S rRNA. The 16S rRNA sequences obtained were compared with those deposited in theGenBank Database and registered with accession number KM052378 as S. toxytricini Fz94.Screening of S. toxytricini Fz94 extract capability in prevention and destruction of C. albicansreference strain biolfilm was assessed by resazurin dye adopted technique. In the pre-exposurescheme, the lowest concentration of 5 gL-1 showed biofilm viability inhibition of 92% after 120min, while Ketoconazole® gave 90 % inhibition at concentration of 2 gL-1. In post exposure, theconcentration of S. toxytricini Fz94 extract 7gL-1 caused 82 % inhibition of biofilms viabilityafter 120 min, while Ketoconazole did not show any destruction capability. The cytotoxicity ofS. toxytricini Fz94 crude extract results showed that it was nontoxic at 10 gL-1. S. toxytriciniFz94 is maintained in the Fungarium of Arab Society for Fungal Conservation (ASFC) withaccession number FSCU-2017-1110.
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