with different species , such as enterobacter , citrobacter , indole-positive proteus , serratia , aeromonas , and pseudomonas , which produce an inducible chromosome-encoded cephalosporinase , antagonism will appear if one of the two combined antibiotics causes induction of the beta-lactamase and the other becomes inactivated by the increased amount of the enzyme .
C0728805
cephalosporinase
C0597979
beta-lactamase