Antimicrobial activity of bioactive glass S53P4 against representative microorganisms causing osteomyelitis – real-time assessment by isothermal microcalorimetry

Publication date: Available online 7 February 2020Source: Colloids and Surfaces B: BiointerfacesAuthor(s): Mercedes Gonzalez Moreno, Maria Eugenia Butini, Elena Maryka Maiolo, Laura Sessa, Andrej TrampuzAbstractBioactive glass (BAG) is a synthetic bone substitute with intrinsic antimicrobial properties, used for bone defect filling. We evaluated the antimicrobial activity of two formulations of BAG S53P4 against representative pathogens of osteomyelitis: Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Escherichia coli and Candida albicans. Antimicrobial activity of BAG S53P4 was assessed by isothermal microcalorimetry, a highly sensitive assay measuring metabolic-related microbial heat production in real-time. Standard CFUs-counting was performed in parallel. BAG granules (diameter 500-800 µm) and powder (<45 µm) were evaluated in two concentrations (400 and 800 mg/ml). Isothermal microcalorimetry was performed in glass ampoules containing growth medium, BAG and test microorganism, heat production was measured for 24 h. BAG S53P4 inhibited heat production of most tested microorganisms with heat reduction of 60% to 98% compared to positive control after 24 h of exposure to the highest tested concentration (800 mg/ml). BAG S53P4 in powder formulation (<45 µm) inhibited more microbial growth than in granule formulation (500-800 µm), with the exception of C. albicans for which both formulations presented similar inhibition rat...

Source: Colloids and Surfaces B: Biointerfaces - February 8, 2020 Category: Biochemistry Source Type: research