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Published on: May 5, 2016
Norfloxacin and ursolic acid: in vitro association and postantibiotic effect against Staphylococcus aureus
A Filocamo1, C Bisignano, M D'Arrigo
1Pharmaco-Biological Department, University of Messina, Messina, Italy.
Aims:
We investigated the effectiveness in vitro of the association between norfloxacin (NOR) and ursolic acid (UA) against Staphylococcus aureus.
Methods And Results:
The minimal inhibitory concentrations (MICs), the minimal bactericidal concentrations, the bacterial killing and the postantibiotic effect (PAE) of NOR and UA were determined both singly and in combination. A synergistic interaction was observed against Staph. aureus ATCC 29213: the mean PAEs were 3 h for NOR, -1.2 h for UA (1 × MIC) and 2.0 h for UA (2 × MIC). Synergism was observed with longer PAEs and postantibiotic sub-MIC effects after NOR/UA exposure. UA was also active against clinical isolates and methicillin-resistant Staph. aureus.
Conclusions:
The application of antimicrobial combinations may address the rising resistance to established classes of both systemic and topical agents.
Significance And Impact Of The Study:
In vitro interactions between NOR and UA may contribute to the development of novel topical agents for the treatment of skin infections as well as for topical formulations.
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