<prompt> Which of the following antimicrobial is effective against an organism producing extended spectrum beta lactamase?Amoxicillin-Clavulinic acidCefepimePiperacillin-TazobactamCeftriaxone  <response>: Ans. C Piperacillin-tazobactamRef: Harrison 18th1247Organisms producing ESBL-like Klebsiella are resistant to most beta-lactams except carbapenems.ESBL can be inhibited by beta lactamase inhibitors.Amoxicillin is not effective against Klebsiella whereas piperacillin has wide spectrum including Klesiella. 