PeterPen-SPICE-M will expland the PeterPen trial. In PeterPen we recruit patients with bacteremia caused by 3rd generation cephalosporin-resistant E. coli or Klebsiella pneumoniae. In SPICE-M we will recruit also patients with bacteremia caused by 3rd generation cephalosporin-resistant Serratia marcescens, Providencia stuartii & rettgeri, Indole positive Proteus spp. (Proteus vulgaris), Citrobacter freundii, Enterobacter cloacae, Klebsiella aerogenes and Morganella morganii. In both trials patients will be allocated within 72 hours of blood culture taking to piperacillin-tazobactam vs. meropenem to complete at least 7 days of covering antibiotic therapy.
Data regarding optimal treatment for extended-spectrum beta-lactamase (ESBL) producing Enterobacterales bloodstream infection are lacking. Observational studies show conflicting results when comparing treatment with combination beta-lactam-beta-lactamase inhibitor and carbapenems. The investigators aim to evaluate the effect of definitive treatment with meropenem vs. piperacillin-tazobactam on the outcome of patients with bacteremia due to cephalosporin-non-susceptible Enterobacteriaceae. The investigators hypothesize that piperacillin-tazobactam is non-inferior to meropenem.