Comparison of risk factors and outcome in patients with Enterococcus faecalis vs Enterococcus faecium bacteraemia

The purpose of our study was to determine retrospectively the risk factors for the acquisition of Enterococcus faecalis vs E. faecium bacteraemia, as well as the clinical outcomes of these patients. 62 patients with Enterococcus faecalis bacteraemia were compared to 31 patients with E. faecium bacteraemia. Haematologic malignancies, neutropenia, high-risk source and previous use of aminoglycosides, carbapenems, cephalosporins and clindamycin were significantly associated with E. faecium bacteraemia. Instead, urinary catheterization was found to be related to Enterococcus faecalis bacteraemia. The mortality rates within 7 d and 30 d were 13% and 27%, respectively, in patients with E. faecalis bacteraemia and 6% and 29%, respectively, in patients with E. faecium bacteraemia. There was no difference in mortality between E. faecalis and E. faecium bacteraemia, nor was there a difference in seriousness of disease at the time of bacteraemia. In the subgroups of patients with monomicrobial or clinically significant E. faecalis vs E. faecium bacteraemia, the mortality rates were similar to the results of all subjects. Our results do not support the theory that E. faecium would be a more virulent organism than E. faecalis.