Inclusion Criteria:  Primary or secondary bloodstream infections by any specie of the Enterobacterales family with minimum inhibitory concentration (MIC) for meropenem >32mg/L; Agreement of the assistant team with the inclusion of the patient in the study; Agreement by the patient or legal guardian to sign the informed consent form.  Exclusion Criteria:  Known pregnancy; Patients belonging to the population deprived of their liberty; Known allergy to meropenem; Use of ceftazidime-avibactam (or any other new antimicrobial agent that become available in Brazil during the study period) for the treatment of the current infection; Infection by an Enterobacterales isolates without in vitro susceptibility to at least one antimicrobial drug; Bloodstream co-infection by another gram negative bacilli; Concomitant infection at any site by a pathogen which meropenem is indicated; Neutropenia (<1000 neutrophils cells/mm3) Death expected within 48 hours of eligibility assessment.