<prompt> Treatment of choice for extended spectrum beta- lactamase producing enterococci:Amoxicillin-clavalunic acidPiperacillin-TazobactamAmpicillin onlyAmpicillin Sulbactam  <response>: Ans. b. Piperacillin-Tazobactam Ref: Katzung 11e p599Piperacillin-Tazobactam is the treatment of choice for extended spectrum beta-lactamase producing enterococci.Extended Spectrum Beta-LactamaseDefinition: 3rd generation cephalosporin resistanceESBL ClassificationAmblerBusch-Joyce A, B, C, D based upon their amino add sequence Drug of Choice:- A: Carbapenam serine beta- lactamase- B: Monobactam require Zn2 for its activity- C: 4th generation cephalosporin- D: No DOC chelating agentNaCI Resistance sensitivity testing into 1, 2, 3, 4 with subgroupsExtended spectrum beta lactamases ESBLsESBLs are beta-lactamases that hydrolyze extended-spectrum cephalosporins with an oxyimino side chainQ.These cephalosporins include cefotaxime, ceftriaxone, and ceftazidime, as well as oxyimino-monbactam AztreonamQ.The clinical relevance of ESBLs has been well documented by numerous published case reports describing clinical failures with the use of third- generation cephalosporins such as these oxyimino-cephalosporins cefotaxime, ceftriaxone, ceftazidime as well as with the use of cefoxitin and the fourth generation cephalosporin, cefipime.Most ESBLs are inhibited by beta-lactamases inhibitors such as clavulanate, sulbactam, or tazobactam in vitro; but the clinical effectiveness of beta- lactambeta-lactamase inhibitor combinations cannot be relied on consistently for therapy. In fact, the therapy of choice for infections caused by ESBL- producing members of the Enterobacteriaceae is a carbapenam. 