ESBL-producing Enterobacteriaceae Infections

The goals of this observational study are to identify risk factors for ESBL-producing Enterobacterales and carbapenemase-producing Enterobacterales (CPE) colonization in oncohematological patients with severe neutropenia, and to develop and validate a predictive model of infection caused by ESBL-producing Enterobacterales and CPE in patients previously colonized by the same bacteria. The main questions the study aims to answer are: * What are the risk factors for ESBL-producing Enterobacterales and CPE colonization in patients with severe neutropenia? * Can a predictive model be developed to accurately predict infections in the colonized patients? Study Design \& Participants: Participants will be screened after receiving neutropenia-inducing treatment (e.g., chemotherapy, chimeric antigen receptor T-cell (CAR-T) therapy, or others). A baseline rectal swab will be collected to assess initial colonization status, followed by weekly swabs throughout the duration of neutropenia. Patients will be followed for 90 days from initial screening, during which the study team will record any infections, with an additional 30-day follow-up period. All hospitalization data will be recorded.