Bacterial infections after liver transplantation.

Infection is a common complication of orthotopic liver transplantations and a major cause of mortality. Of the different types of infection, severe bacterial infections are the most common. The majority (81%) of bacterial infections occur within the first two months after liver transplantation. The most frequent site of infection is the abdomen (intrahepatic or extrahepatic abscesses, cholangitis, and peritonitis). Bacteremia is a marker of mortality, and the majority of bacteremia cases are secondary to another bacterial infection site. The causative organisms vary among different centers. In some, gram-negative organisms are more common (66%); in one center, however, gram-positive microorganisms predominate (66%). In the latter center, the use of nonabsorbable antibiotics, which eradicate gastrointestinal aerobic gram-negative microorganisms, may explain this microbiologic difference. The main risk factor predisposing to bacterial infection appears to be the duration of the transplantation operation, especially beyond 12 hours. Of the deaths resulting from infection, 81% were caused by bacterial infection.