There is a lack of data whether colonization and infection with Enterobacteriaceae of the third group (EB3) affect the outcomes for ICU patients. This study evaluated the effects of EB3 colonization and infection on ICU mortality, ICU length of stay (LOS) and broad-spectrum antibiotic exposure. We focused on the sub type Enterobacter regarding its a priori higher risk of resistance.

Inclusion Criteria:

• adults critically ill patients admitted to the the participating ICUs during the study period
• with colonization and/or infection with a third group enterobacteriacea
• and with a lenght of stay > 24h

Exclusion Criteria:

• minors patients
• lenght of stay < 24h

All adults (≥ 18 years-old) patients admitted in the participating ICUs with LOS ≥ 24 hours during the study period were enrolled if they had presented a colonization and/or an infection caused by an EB3 (Enterobacter cloacae, Enterobacter aerogenes, Morganella morganii, Serratia marcescens, Hafnia alvei et Citrobacter freundii), from 1st January 2016 to 31th December 2016.

Participating ICUs of the university hospital of Nancy:

• two Medical ICU
• 3 surgical ICU