Predictors of carried ESBL-producing Enterobacterales involvement in ICU-acquired infection: insights from a bicentric retrospective cohort study.

Rationale: Infections due to Extended-spectrum {beta}-lactamases-producing Enterobacterales (ESBL-PE) require empirical treatment with carbapenems. ESBL-PE carriage is considered as a risk factor for ESBL-PE involvement during ICU infection. Our aim was to determine factors that may predict the actual involvement of ESBL-PE. Methods: A two-periods bicentric ambispective study including ICU ESBL-PE carriers patients from April 2011 to January 2019. All ESBL-PE carriers who developed an infection were analyzed. Results: 6112 patients and 4902 patients were screened during the two periods. 384 and 232 ESBL-PE carriers were identified. Total number of infectious episodes were 146 and 114, respectively. A total of 144 pneumonias, 42 urinary tract infection and 45 digestive infections were studied. An ESBL-PE was involved in 35 (24.3%) episodes of pneumonia, and 44 (37.9%) of extra-pulmonary infections. The most frequent ESBL-PE involved were K. pneumoniae, E. cloacae and E. coli. Similar species and phenotypes were present in colonisation and infection in 29 (82.8%) of pneumonia and in 40 (90.9%) of extra-respiratory infection. Multivariate analysis identified Klebsiella pneumonia or Enterobacter cloacae carriage as risk factor for ESBL-PE involvement in pneumonia and E. coli carriage and detection of ESBL-PE carriage before ICU admission as protective factors. Conclusion: In our study an ESBL-PE involvement is infrequent in pneumonia. A known carriage before ICU admission and E. coli carriage are factors associated with the absence of ESBL-PE un the episode of respiratory infection. A confirmation of our findings could lead to a reduction in the empirical use of carbapenems in this population.