The recombinant plasmids expressing pentapentidic proteins in E. coli DH10B increased the MICs from 4 to 12 folds for nalidixic acid, from 6 to 24 folds for ofloxacin, from 2 to 47 folds for norfloxacin, from 12 to 32 folds for ciprofloxacin, from 4 to 21 folds for levofloxacin, and from 4 to 32 folds for moxifloxacin.