Microbiological evaluation of piperacillin-tazobactam alone and in combination with amikacin versus meropenem against extended spectrum beta-lactamase-producing and non-producing Escherichia coli and Klebsiella pneumoniae clinical isolates

Extended-spectrum beta-lactamase (ESBL) expression in Escherichia coli and Klebsiella pneumoniae confers resistance to a wide range of beta-lactam antibiotics. Carbapenems are recommended therapeutic choice for severe ESBL-infections, although excessive usage has been associated with escalating prevalence of carbapenem-resistance. We aimed to evaluate pharmacodynamic activity of piperacillin-tazobactam alone and in combination with amikacin compared to meropenem against ESBL-producing and non-producing E. coli and K. pneumoniae clinical isolates in an in vitro dynamic hollow-fibre infection model.