Spectrum of early-onset and late-onset bacteremias after liver transplantation: implications for management.

Bacteremia is a significant cause of morbidity and mortality after liver transplantation. The characterization of the microbiological spectrum of bacteremia after liver transplantation may help physicians in choosing the initial empirical antimicrobial therapy for patients presenting with sepsis. The clinical and microbiology records of patients who received liver transplantation from January 1997 to March 2006 were reviewed. One hundred twenty-three of the 737 liver recipients (16.7%) developed bacteremia during the median follow-up period of 5.8 years (interquartile range = 2.5-8.8 years); 92 patients (12.5%) had gram-positive bacteremia (GPB), whereas 47 (6.4%) had gram-negative bacteremia (GNB). Nosocomial bacteremia was significantly more frequent among patients with early-onset GPB or GNB versus patients with late-onset GPB (66.7% versus 23.7%, P < 0.001) or GNB (70.6% versus 20.0%, P = 0.001). Peritonitis (33.3% versus 7.9%, P = 0.004) and wound infections (13.0% versus 0%, P = 0.04) as sources were more common in patients with early-onset GPB versus patients with late-onset GPB. Likewise, peritonitis was a more common source of early-onset GNB than late-onset GNB (41.2% versus 6.7%, P = 0.007). Staphylococcus aureus and Enterococcus faecium were the most common pathogens in patients with early-onset GPB, whereas Enterococcus faecalis and Streptococcus species were most common in patients with late-onset GPB. Pseudomonas aeruginosa and anaerobes were the most common pathogens in patients with early-onset GNB, whereas Escherichia coli was most common in patients with late-onset GNB. In conclusion, the microbiological spectra of early-onset and late-onset bacteremias differ, and this should be considered by those determining the initial empirical treatment of liver transplant recipients suspected to have bacteremias.