Stool cultures obtained before liver transplantation are useful for choice of perioperative anti biotic prophylaxisAbstract Bacterial infections, especially cholangitis, are still common complications after liver transplantation (LTx). During recent years, multiresistant enterococci have become a nosocomial problem in transplant units. The present prospective study on 26 patients, including 24 patients with chronic liver disease, demonstrated that enterococci were the predominant micro-organism involved in post-LTx bacterial infections. They were cultured in the feces and in other sites of 10 out of 13 (77 %) patients who underwent extensive examinations. Ampicillin-resistant Enterococcus faecium strains were isolated in urine or feces of 2 of the 13 patients prior to LTx. Similarly, resistance to ampicillin and gentamicin, the empirically used antibiotics for patients with fever of unknown origin, was found in E. faecium strains in 3 and 2 patients, respectively. Moreover, multiresistant E. faecium and E. faecalis strains were demonstrated in 46 % of the patients in the postoperative period (3 months). However, no vancomycin-resistant enterococci were isolated. The use of antibiotics within 4 months prior to LTx significantly increased the risk of developing ampicillin-resistant bacteria at the time of LTx and of infections with bacteria of enteric origin after LTx ( P = 0.03 and 0.01, respectively). We conclude that stool and urine cultures performed prior to LTX may be useful for selecting prophylactic antibiotic regimens.