Enteral nutrient solutions. Limiting bacterial growth.

Bacterial contamination of enteral nutrient solutions ( ENS ) in FFcess of food product standards is known to occur in the hospital setting. The large amounts of bacteria often given with ENS have been shown to create a reservoir for nosocomial infections, and nonpathogenic bacteria have been implicated. Patient tolerance is dependent on immune status and the bacterial load delivered to the gut. The purpose of this study was to evaluate the bacterial growth-sustaining properties of various ENS and to devise methods to limit bacterial growth. Five commercial products were prepared under sterile conditions. After inoculation with approximately 5 X 10(3) organisms/cm3 of Enterobacter cloacae, each solution was hung at room temperature for 24 hours with samples drawn at fixed intervals and plated for bacterial counts. Bacterial growth rates in Ensure, Travasorb , and Vital were markedly higher than those in Precision and Vivonex. Vivonex was noted to contain potassium sorbate (KS) used as a fungistatic agent. Recent studies have identified KS as a broad-spectrum bacteriostatic food preservative that is federally approved for this use. KS (0.03%) was added to Travasorb inoculated with 5 X 10(3) organisms/cm(3) of E. cloacae. The bacterial growth rate was reduced by 75 per cent, and the final count of 2-3 X 10(4) organisms/ml was within the federally regulated limit for milk. This study suggests that initial inoculum, growth rate, and hang time can be altered to provide a significant reduction in final bacterial counts in ENS .