The main objective of the study is to describe the antimicrobial resistance profile of E. coli isolated in patients from the community - defined as those with cultures collected within 48 hours of hospital admission - and admitted to the intensive care unit.

Background: The growing antimicrobial resistance in bacterial pathogens represents a severe public health problem. Isolation of Escherichia coli ESBL has been identified more frequently over the years due to the worldwide dissemination of strains with this phenotypic profile. The ICU has a fully functioning Antimicrobial Stewardship team, with data managed daily. Thus, the investigators identified increasing E. coli ESBL isolates resistant to standard empiric antimicrobial therapy in community-based severe infections.

Purpose: The choice of empirical antimicrobial therapy is an increasingly present challenge in clinical practice, often determining the outcome of critically ill patients. As this is a highly relevant topic in managing this patient profile, antimicrobial stewardship protocols are essential in health services, enabling continuous community monitoring of emerging resistance profiles. The justification for this study is based on the possibility of adding knowledge on the topic, aiming to add to the global theoretical collection and alert about the locoregional occurrence of changes in the bacterial resistance profile.

Objectives: The main objective of the study is to describe the antimicrobial resistance profile of E. coli isolated in patients from the community - defined as those with cultures collected within 48 hours of hospital admission - and admitted to the ICU.

Inclusion Criteria:

• All 18 years and old patients admitted to the ICU
• Positive cultures for E. coli
• Any sample collected within 48 hours of hospital admission

Exclusion Criteria:

• Lack of necessary data

Adult patients with severe Escherichia coli infections, isolated from any culture material collected within less than 48 hours of hospital admission, admitted to the intensive care unit of a tertiary hospital.