Molecular epidemiology of Enterococcus faecalis in liver transplant patients at University Hospital Groningen.

We report the molecular epidemiology of Enterococcus faecalis in liver transplant patients transplanted at the University Hospital Groningen (The Netherlands) as determined by amplified fragment length polymorphism (AFLP) typing. A total of 133 E. faecalis isolates were cultured from the faeces and throat (95 isolates) or clinical sites (35 isolates) of 43 liver transplant patients. Among these 133 isolates, 15 different AFLP types could be identified with 90% AFLP similarity. Of these 15 groups, nine contained isolates from more than one patient, which may indicate transmission of E. faecalis isolates between patients. In five of these groups transmission could be explained by the fact that patients carrying identical strains were staying in the same ward at the same time. One of these epidemic isolates (AFLP type K) distinguished itself by colonizing 23 liver transplant patients during 15 months. Antimicrobial susceptibility testing did not reveal any multi-resistant isolates. This study showed that transmission of susceptible E. faecalis isolates occurs frequently on the liver transplant wards. Detection of this transmission and understanding of the mechanism is important, as it might also be an indicator of possible transmission of enterococci resistant to antibiotics.