Parenteral infusions as culture media from a viewpoint of nosocomial bacteremia.

OBJECTIVE: To assess the growth patterns of selected organisms in common parenteral solutions, in order to ascertain implications for nosocomial bacteremia. DESIGN: A microbial suspension of approximately 300 CFU/mL was sequentially inoculated into common parenteral infusions from three different manufacturers and incubated at room temperature. Initially, 11 bacterial isolates and one Candida species from clinical specimens were studied. Eight gram-negative rods (GNR) were tested at varying pH's. Species variability was examined by testing an additional 39 isolates. RESULTS: The eight GNR grew in Ringer's lactate (RL) from two manufacturers and only two grew in dextrose 5% in water (D5/W) (Klebsiella pneumoniae and Serratia marcescens). No organism grew in saline or dextrose 5% in saline. The gram-positive cocci and Candida did not grow in any solution. No significant changes in growth were found after modifying the pH of solutions. Significant inter- and intra-species growth variability was noted. CONCLUSIONS: RL is a good culture media for GNR and D5/W is a poor culture media with the exception of some bacteria of the Tribe Klebsielleae. We recommend to follow high standards of nursing practice for administering intravenous infusions and to avoid nutrient-containing solutions for prolonged parenteral use, when possible.

Parenteral infusions bacterial contamination in a multi-institutional survey in Mexico: considerations for nosocomial mortality.

BACKGROUND: Parenteral infusions can be contaminated during administration (extrinsic contamination). A previous survey found that extrinsic contamination was not uncommon in a hospital in Mexico with lapses in aseptic techniques. To determine whether this problem exists in other similar institutions, we undertook a multi-institutional study. METHODS: We surveyed 6 hospitals (A to F) lacking an infection control committee to determine the level of extrinsic contamination. We visited each hospital and obtained samples of all the parenteral infusions in use, drawing 0.5-1 mL from the tubing injection port. Quantitative and qualitative bacterial cultures were performed. Chlorine levels of the tap water were measured. Visits were repeated until the survey was completed. RESULTS: A total of 751 infusions were cultured, of which 16 (2.13%) were contaminated. Hospital contamination rates varied from zero to 5.56%. Klebsiella pneumoniae was the most common isolate (10 cases). During the first sampling day in hospital C, the 7 infusions from the pediatric ward were found to be contaminated with a similar K pneumoniae strain. In-service education was started in this hospital. Infusion contamination was eliminated followed by a reduction in mortality rate. Overall, a higher risk for infusion contamination was noted for pediatric patients (P =.01, odds ratio = 3.28, 95% CI, 1.10-9.91) and in wards with inadequate water chlorine levels (P =. 02, odds ratio = 3.64, 95% CI, 1.08-13.51). CONCLUSIONS: If the hospitals surveyed are representative of others in developing countries, an endemic level of parenteral infusion contamination could exist in many hospitals throughout the world.