Extended spectrum beta lactamases (ESBLs) are characterized by activity against all except.: (A) Penicillinases, (B) Cephalosporinases, (C) Oxyimino-cephalosporinases, (D) Carbapenems
Answer is D. Ans. (D) Carbapenems(Ref: Katzung 10/e p739)Carbapenems like imipenem are the only beta lactams reliably efficacious against ESBL producing bacteria.