Impact of Specific Antimicrobials and MIC Values on the Outcome of Bloodstream Infections Due to ESBL- or Carbapenemase-producing Enterobacterales in Solid Organ Transplantation: an Observational Multinational Study.

Inclusion Criteria: * Solid Organ Transplant patients, including multivisceral transplantation and transplant in HIV-infected recipients. * Episodes of clinically significant monomicrobial BSI due to cephalosporin-resistant Enterobacterales (CRE), specifically ESBL or carbapenemase-producing Enterobacterales, including community and nosocomial ones. Characterization of the resistance mechanisms should be based on the following criteria: * For cephalosporin resistance: a susceptibility phenotype based on a microdilution antibiogram. * For ESBL-producers: one phenotypic confirmation test according to current endpoints (i.e. CLSI, EUCAST) or PCR-based characterization. * For carbapenemase-producers: molecular detection of the carbapenemase gene or if the isolate showed an identical phenotype to previously characterized carbapenemase-producers detected at the same site. * Subsequent episodes in a patient caused by the same microorganism may be included if the interval between them is \>3 months. Exclusion Criteria: * Polymicrobial or non-clinically significant episodes. Episodes in which a potential contaminant (e.g., coagulase-negative staphylococci) is isolated only in one set of blood cultures and there is not a typical source of infection for that kind of organism (e.g. catheter-related) that can be included. * Unavailability of key data (such cases should be counted to analyse a potential selection bias). * Episodes occurring before January 2004.