Positive cultures of organ preservation fluid predict postoperative infections in solid organ transplantation recipients.

OBJECTIVE: The significance of positive cultures of organ preservation fluid (OPF) in solid organ transplantation is not known. We sought to describe the microbiology and define the clinical impact of positive OPF cultures.
DESIGN: Retrospective cohort study.
SETTING: Tertiary care hospital. PATIENTS: A consecutive sample of all solid organ transplantations at our center between July 2006 and January 2009 was reviewed. A total of 331 allografts (185 kidneys, 104 livers, 31 pancreases, and 11 hearts) met the inclusion criterion of having OPF cultures taken from the transplanted allograft.
METHODS: Organisms recovered from OPF were classified as high or low risk according to their virulence. Clinical outcomes were compared between recipients of organs with positive OPF cultures and recipients of organs with negative OPF cultures.
RESULTS: OPF cultures were positive in 62.2% of allografts and yielded high-risk organisms in 17.8%. Normal skin flora constituted the majority of positive OPF cultures, while Enterobacteriaceae spp. and Staphylococcus aureus made up the majority of high-risk organisms. Recipients of allografts with positive OPF cultures developed more frequent bacterial infections, regardless of allograft type (relative risk, 2.39; 95% confidence interval [CI], 1.61-3.54). Moreover, isolation of a given organism in OPF samples was associated with the development of a clinical infection with the same organism, regardless of allograft type.
CONCLUSIONS: Positive cultures of OPF are common events in solid organ transplantation, frequently involve high-risk organisms, and are associated with the development of postoperative clinical bacterial infections. Further study is required to determine the optimal strategies for their prevention and management.