The MERINO Trial was a landmark study published in 2018 that investigated piperacillin-tazobactam versus meropenem for the treatment of bloodstream infections caused by ceftriaxone-resistant Escherichia coli or Klebsiella pneumoniae. An international network was developed to recruit subjects, and since publication that network has expanded to encompass randomised trials for blood stream infections by ESCaPM antibiotic-resistant gram-negative bacteria (MERINO2) and ESBL and AmpC-producing enterobacterales (MERINO3), with a fourth study on the way.