Low-level microbial contamination of liquid in syringe hubs leads to an unacceptable risk to the end product

J Pharm Pharmacol. 2011 Feb;63(2):164-8. doi: 10.1111/j.2042-7158.2010.01201.x. Epub 2010 Nov 16.

Abstract

Objectives: The aim of this study was to assess the risk associated with microbial contamination in the hub-fluid in Luer-lock syringes to the end-product, and ultimately patients.

Method: The hub-fluid of 48 sterile syringes prefilled with broth was contaminated with a low number of Staphylococcus epidermidis or spores of Bacillus subtilis. After incubation for three weeks, the syringe fills were tested for the presence of bacterial contaminants and some syringes were used to inoculate an end product broth that was then investigated for the presence of microorganisms.

Key findings: After three weeks of incubation only 20.8% of syringe fills showed turbidity, although following further investigation 70.8% were positive for the presence of viable bacteria, whereas 95.6% of end products became contaminated following injection of the syringe fill.

Conclusions: These findings add quantitative data that support the current practice of discarding syringes with residue around the cap.

MeSH terms

  • Bacillus subtilis / growth & development*
  • Equipment Contamination*
  • Risk Factors
  • Staphylococcus epidermidis / growth & development*
  • Syringes / microbiology*