Parenteral infusions as culture media from a viewpoint of nosocomial bacteremia

Objective. To assess the growth patterns of selected organisms in common pa renteral solutions, in order to ascertain implications for nosocomial bacte remia. Design. A microbial suspension of approximately 300 CFU/mL was seque ntially inoculated into common parenteral infusions from three different ma nufacturers and incubated at room temperature. Initially, 11 bacterial isol ates and one Candida species from clinical specimens were studied. Eight gr am-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 dextr ose 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 intr a-species growth variability was noted. Conclusions. RL is a good culture m edia for GNR and D5/W is a poor culture media with the exception of some ba cteria of the Tribe Klebsielleae. We recommend to follow high standards of nursing practice for administering intravenous infusions and to avoid nutri ent-containing solutions for prolonged parenteral use, when possible.