Resistant Bacteria in Children in France

Inclusion Criteria: * Children under 18 years of age * Hospitalized in France in a hospital center working with the ACTIV/GPIP network * Treated with one or more of the following antibiotics: * Colimycin (Colistimethate sodium) * Cefiderocol * Aztreonam in combination * Ceftolozane-Tazobactam * Ceftazidime-avibactam * Meropenem/vaborbactam * Imipenem/Relebactam * Tigecycline * Daptomycin * Ceftaroline fosamil * Tedizolid phosphate * Fidaxomicin * Ceftobiprole * Dalbavancin In association with a documented infection performed by: * Blood culture * Normally sterile site * Cerebrospinal fluid * Pleural fluid * Pleura * Peritoneum * Joint fluid * Other * Urine sampling if the bacteria was considered responsible for the infection (associated with a leukocyturia ≥10,0000) * Respiratory specimens if the bacteria was considered responsible for the infection * Sampling on material such as:Intubation probe, Orthopedic, Urological, Central Nervous System (CNS),.... * Related to colonization with multidrug-resistant bacteria without documentation. Exclusion Criteria: * Refusal of participation by the patient or his/her parent * Medical history of mucoviscidosis