STAPHYLOCOCCUS-AUREUS NASAL COLONIZATION AND ASSOCIATION WITH INFECTIONS IN LIVER-TRANSPLANT RECIPIENTS

Background. Staphylococcus aureus has emerged as a leading cause of ba cterial infections after liver transplantation. However, the role of n asal colonization in the development of S aureus infections has never been explored in liver transplant recipients. The objectives of this s tudy were to determine whether nasal carriage of S aureus was a risk f actor for S aureus infections in liver transplant recipients. Methods, Over a a-year period, 30 consecutive liver transplant recipients were studied. Beginning when the recipients were transplant candidates, na sal cultures were performed at each admission and monthly thereafter u ntil discharge or death, Results, Overall, 67% (20/30) of the patients were nasal carriers, 70% of the carriers had methicillin-resistant S aureus (MRSA), 15% had methicillin-sensitive S aureus, and 15% had bot h MRSA and methicillin-sensitive S aureus, Infections were significant ly associated with the carrier state; 100% (9/9) of the infected patie nts were carriers as compared with 50% (11/21) of the noninfected pati ents (P=0.01), All infections were a result of MRSA, and 56% (5/9) of the infections were bacteremia. Median time to the onset of S aureus i nfections was 16 days after transplant. Pulse field gel electrophoresi s (with digestion of S aureus with SmaI restriction enzyme) in seven i nfected patients demonstrated that the isolates from the anterior nare s matched the invasive isolates in all cases. A total of 43% (3/7) of these infected patients shared the same restriction pattern. Conclusio n. MRSA colonization of the anterior nares was a significant predictor of MRSA infections in liver transplant recipients, Infections occurre d only in those colonized with MRSA and were a result of the endogenou sly colonizing S aureus strains in all cases.