Sensitizing of β-lactam resistance by tannic acid in methicillin-resistant S. aureus

In this study, after minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) of sole tannic acid and β-lactam were investigated for each isolate, the synergistic activities of β-lactams combined with tannic acid against one MRSA ATCC 43300 and four MRSA clinical isolates were investigated with the concentrations starting at four fold of MICs of sole treatments of tannic acid and β-lactam by using checkerboard assay. To investigate sole and combination activities of tannic acid an d β-lactams, MIC and MBCs were observed. Results of this study showed that the activities of β-lactams combined with tannic acid were synergistic and partially synergistic against MRSA isolates with FIC indexes ranged from 0.174 to 0.477 and 0.562 to 0.850, respectively. MIC of β-lactams were dec reased 2–16 fold by sub-inhibitory concentrations of tannic acid without toxicity. Alternative treatment options of natural compounds such as tannic acid and β-lactams must be investigated further and developed to overcome the emergence of β-lactam resistance and treat MRSA infections by sensiti zing the resistance of β-lactams.
Source: World Journal of Microbiology and Biotechnology - Category: Microbiology Source Type: research