2. Ensuring Sterility of Enteral Feeding SystemsThe TheoryThe feeding solution provides a medium for microbial contam- ination and a biofilm is highly likely on the internal surfaces of the feeding tube and delivery system. If this occurs, gut symp- toms might result from infusion of contaminated liquid into the gastrointestinal tract. Indeed, in an intensive care unit in which 50 patients underwent feedings for a period of at least 4 days, 4% of initially sterile feeds were contaminated with Enterobacter cloacae, Klebsiella oxytoca and Enterococcus spp.The most frequent site of retrograde growth of endogenous bacterial contamination are both the feeding tube and delivery system.The hang time is important; 24% of delivery sets are reported to be unacceptably contaminated after 24 hours