Bacteria isolated from bile samples of liver recipients in the early period after transplantation: epidemiology and susceptibility of the bacterial strains.

OBJECTIVE: We estimated the frequency and susceptibility to antibacterial agents of bacterial isolates from bile samples obtained from 83 liver recipients in the early period after transplantation.

PATIENTS AND METHODS: We prospectively collected data on 83 adult patients undergoing orthotopic liver transplantation (OLT), including bile samples taken during the first 30 days after OLT from adult liver recipients suspected to have bile infections. The isolation/identification of cultured bacteria was performed according to standard microbiological procedures and commercially available tests. Susceptibility of the strains to antibacterial agents was determined according to the Clinical and Laboratory Standards Institute (CLSI) guidelines.

RESULTS: Among 210 bile samples obtained from 79 liver recipients, bacterial cultures were positive in 110 samples from 59 (75%) recipients yielding 156 bacterial strains. The most commonly isolated species were as follows: gram-positive cocci (109 isolates) with dominance of coagulase-negative staphylococci (52%) and enterococci (36%); and gram-negative bacteria, 21 strains from the Enterobacteriaceae family and 14 of non-fermenting rods. We identified some multidrug-resistant (MDR) bacterial strains. In the first week after OLT, we investigated samples from 59 patients, yielding 36 bacterial strains. From the second to the end of the fourth week after OLT, 120 bacterial strains were isolated from 65 recipients.

CONCLUSION: Gram-positive bacteria comprised 68.5%. The dominance of MDR gram-positive bacteria may be related to selection by perioperative antibiotic prophylaxis.