The growth of micro-organisms in parenteral nutrition solutions containing amino acids and sugars

Abstract

The viability of various micro-organisms in solutions containing crystalline amino acids with and without the inclusion of a carbohydrate was studied. The fungus, Candida albicans, proliferated in all solutions examined. Addition of dextrose in several concentrations or sorbitol did not influence the growth of the fungus. Bacterial growth was, in comparison, considerably inhibited in solutions containing crystalline amino acids alone or in combination with dextrose. Previous publications have indicated that solutions containing crystalline amino acids do not permit bacterial multiplication. In contrast, strains of Pseudomonas aeruginosa and Enterobacter aerogenes employed for this study were observed to multiply in solutions containing 4.25% w/v crystalline amino acid and 25% w/v dextrose. The substitution of dextrose with sorbitol resulted in further inhibition of the majority of bacteria.