A Study to Assess How Vaborem® is Taking up in the Body and Tolerated in Paediatric Patients With Gram Negative Infections, Including But Not Restricted to Complicated Urinary Tract Infections

Main Inclusion Criteria: * Written informed consent before initiation of any study-related procedures. * Male or female, from birth to \< 18 years of age, inclusive. * Require hospitalization and a minimum of 3 days of IV antibiotic treatment for suspected or confirmed Gram negative infection as per Investigator's judgement. * Gram negative infection, according to diagnostic criteria for complicated urinary tract infection/acute pyelonephritis (cUTI/AP), complicated intra-Abdominal Infections (cIAI), Hospital-Acquired Pneumonia/Ventilator Associated Pneumonia (HAP/VAP), Blood-Stream Infection (BSI). Main Exclusion Criteria: * History of any moderate or significant hypersensitivity or allergic reaction to beta-lactam antibiotics or to any component of the investigational medical product. * Gram negative infection that in the opinion of the Investigator is unlikely to respond to the study treatment. * In treatment with immunosuppressive agents, valproic acid, or probenecid.