Antibacterial activity of polymers with norfloxacin moieties against native and norfloxacin-tolerance-induced bacteria

Antimicrobial characteristics were investigated for norfloxacin against 18 bacteria (4 gram‐positive bacteria and 14 gram‐negative bacteria) with the minimum inhibition concentration (MIC) test. Among the bacteria tested, B. cereus, V. fluvialis, and V. parahaemolyticus formed norfloxacin‐tolerant colonies. The release of ultraviolet‐absorbing substances from the cells in contact with norfloxacin was examined for the native bacteria and for the norfloxacin‐tolerance‐induced ones. Norfloxacin was grafted to polypropylene‐graft‐maleic anhydride (MAPP) and poly(styrene‐co‐maleic anhydride) (MAPS) to synthesize polymeric antimicrobial agents. The bioactivity of MAPP–norfloxacin and MAPS–norfloxacin was evaluated and compared with that of neat norfloxacin with the shake flask test and the MIC test. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 936–943, 2005