Survival of Beta-Lactamase-Producing and -Nonproducing Bacteria in Intravenous Solutions

Abstract

The survival of beta-lactamase-producing (β-lac+) and non-beta-lactamase-producing (β-lac-) Bacillus and Staphylococcus spp. has been investigated in dextrose 5% injection, NaCl 0.9%, and dextrose 5% in NaCl 0.9% solutions. Tests were performed under static and turbulent conditions of incubation, with and without antibiotics added to the fluids, and with or without 1% citrated blood. All solutions were inoculated with about 1000 organisms/mL, and sampled for viable bacteria at specific time intervals. Under static conditions, there was no significant decrease in viability (p > 0.01) of the bacilli, except for the staphylococci (p < 0.01). However, when cultures were agitated, all species showed significant decline in viability (p < 0.01). When antibiotics were present, S. aureus (β-lac+) declined gradually throughout 24 hours (p > 0.01). B. cereus (β-lac+) concentrations were static in all solutions. All organisms multiplied rapidly in solutions containing blood. The results suggest that the growth characteristics of both β-lac+ and β-lac- bacteria in intravenous fluids are essentially similar, except in solutions containing beta-lactamase-sensitive antibiotics in which (β-lac+ bacteria tend to survive.

How should we handle epidural solutions? One view

“…Several studies have shown that IV solutions and drugs are at least bacteriostatic 13,14 and, often, bactericidal over time 15 for a wide variety of microorganisms, essentially because they lack the nutrients the bacteria need to survive. One study has shown that refrigerated solutions remain sterile for several months.…”