CreC Sensor Kinase Activation Enhances Growth of Escherichia coli in the Presence of Cephalosporins and Carbapenems.

Mutants with enhanced growth in the presence of an antibiotic are more difficult to identify than mutants where the antibiotic's MIC increases, because they are not amenable to lethal selection in vitro We report that activatory mutations in the CreC signal sensor enhance growth of Escherichia coli in the presence of cefoxitin, cefotaxime, and meropenem, without increasing their MICs. Enhanced growth is dependent on overproduction of the inner membrane cre regulon protein CreD.