Treatment of choice for extended spectrum beta- lactamase producing enterococci:

Ans. b. Piperacillin-Tazobactam (Ref: Katzung 11/e p599)Piperacillin-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 agent/NaCI)* Resistance sensitivity testing into 1, 2, 3, 4 with subgroupsExtended spectrum beta lactamases (ESBLs)ESBLs 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- lactam/beta-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.