Enterobacter meningitis--treatment complicated by emergence of mutants resistant to cefotaxime.

A case of Enterobacter cloacae meningitis in a postoperative patient is reported. A slow response to cefotaxime necessitated the use of gentamicin and trimethoprim-sulfamethoxazole for cure. Two types of resistance in the strain of E. cloacae isolated to cefotaxime were demonstrated: an inducible beta-lactamase that likely was the cause of the poor response to cefotaxime and a constitutive beta-lactamase in a mutant strain detected by a disc susceptibility test.