FURTHER STUDIES ON THE GROWTH OF MICRO-ORGANISMS IN TOTAL PARENTERAL NUTRITION SOLUTIONS

Abstract

Summary The growth of vegetative bacteria in mixtures containing amino acids, dextrose, inorganic salts and vitamins was examined. Escherichia coli and Klebsiella pneumoniae grew rapidly in Aminoplex 14, Vamin-glucose and Aminofusin L600 with 10% w/v dextrose. Growth of E. coli was slower in Synthamin 14 with 10% w/v dextrose. K. pneumoniae was unable to grow in this solution unless vitamins were added. Higher concentrations of dextrose inhibited growth in Synthamin 14, but had little influence on the growth of E. coli or K. pneumoniae in the presence of Vamin-glucose, Aminoplex 14 or Aminofusin L600. Pseudo-monas aeruginosa grew slowly in solutions containing amino acid combinations other than Synthamin 14. Staphylococcus epidermidis was unable to grow in any solutions except those containing Aminofusin L600 where growth was shown to occur only after a long lag phase. Vitamin supplements had little influence on growth rates. No organism was able to grow in any solution stored at 4oC. Results indicate that, to prevent growth of micro-organisms, Total Parenteral Nutrition regimes mixed in 3-1 containers should be stored under refrigeration conditions unless used immediately.