Variation in microbial survival and growth in intravenous fluids

The survival and growth of aerobic and anaerobic bacteria, as well as a yeast, was studied in intravenous fluids over a 3-day period. Solutions were experimentally contaminated with pathogenic strains of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacteroides fragilis and Candida albicans. Samples of these solutions were tested on each day up to 3 days for determining viable numbers of the organisms by a membrane filtration method. Each organism showed a different survival/growth pattern in various infusion fluids. In 5% dextrose, C. albicans multiplied but only 2-3% of the initial viable cells of E. coli, P. aeruginosa, and S. aureus were detected after 3 days. In 0.9% sodium chloride, C. albicans and S. aureus showed growth and E. coli remained viable, but P. aeruginosa was not detected after 72 h. In lactated Ringer's solution, P. aeruginosa and C. albicans grew but E. coli and S. aureus were not detected after 72 h. In the amino acid solution, C. albicans, S. aureus and E. coli grew but P. aeruginosa and B. fragilis were not detected. Results indicate that the pattern of microbial survival and growth may be substantially different in various intravenous fluids