Compositions and methods for inhibiting the growth of Gram-negative and/or Gram-positive bacteria and pharmaceutical compositions for treating infections of such bacteria in humans and animals are provided. An exemplary method for inhibiting the growth of Gram-negative and/or Gram-positive bacteria includes contacting the bacteria or an environment containing the bacteria with a combination of bacitracin and a gallate ester. An exemplary pharmaceutical composition includes bacitracin and a gallate ester.