Cefazolin

BACKGROUND: Ceftolozane/tazobactam (TOL/TAZ) is a novel cephalosporin/beta-lactamase inhibitor with activity against several gram-negative pathogens. Daptomycin (DAP) has demonstrated synergistic activity with beta-lactams against methicillin-resistantS. aureus(MRSA) with reduced lipopeptide and glycopeptide susceptibilities. Our objective was to determine if DAP and TOL/TAZ possess synergy in hollow-fiber pharmacokinetic/pharmacodynamic (PK/PD) models.

Cascade reporting (CR) involves reporting the susceptibilities of broad-spectrum agents only when the organism is resistant to more narrow-spectrum agents. The purpose of this study is to evaluate the impact of CR on antibiotic de-escalation practices and to characterize the impact of CR on clinical outcomes. CR rules were implemented in the microbiology laboratory at Atlantic Health System (AHS) in June 2013. A retrospective chart review was conducted at two community teaching hospitals in adult patients who had a blood culture positive for a Gram-negative organism susceptible to cefazolin and who were empirically treated with broad-spectrum beta-lactam (BSBL) antibiotics. De-escalation practices were compared in the pre-CR (July 2012-December 2012) and post-CR (July 2013-December 2013) periods. The primary endpoint was the percentage of patients whose BSBL agent was de-escalated to agents listed on the post-CR antibiotic susceptibility report within 48 h of the final report.