Induction of L1 and L2 β-lactamase production in Stenotrophomonas maltophilia is dependent on an AmpR-type regulator

A divergently oriented ampR has been located upstream of bla(L2) in Stenotrophomonas maltophilia. AmpR is necessary for L1 and L2 beta-lactamase induction in response to beta-lactam challenge, and activation of AmpR is sufficient to induce L1 and L2 production. L1 induction requires more activation of AmpR than does L2 induction.