Impact of the contamination time by Escherichia coli on biofilm formation in surgical instruments

Rev Bras Enferm. 2021 Jul 14;74(3):e20200759. doi: 10.1590/0034-7167-2020-0759. eCollection 2021.
[Article in English, Portuguese]

Abstract

Objectives: to evaluate the microbial load and adherence of Escherichia coli in different areas of the surgical instrument surface exposed to experimental contamination over time.

Methods: experimental study in which fragments of crile forceps (serrated, rod and rack) were contaminated by immersion in Tryptic Soy Broth, containing 106 CFU/mL of E. coli, for 1, 2, 4, 6, 8, 12 and 24 hours. Microbial load and bacterial adherence were evaluated using microbiological culture and scanning electron microscopy, respectively.

Results: there was an increase in the microbial load on the surgical instrument, proportional to the contamination interval, ranging from 102 after 1 hour to 105 CFU/cm2 in 24 hours. The presence of exopolysaccharide was detected after two hours of contamination.

Conclusions: microbial load and adhesion of E. coli increased over time, reaching 105 CFU/cm2 after 24 hours of contamination, starting biofilm formation after two hours.

MeSH terms

  • Biofilms
  • Colony Count, Microbial
  • Escherichia coli*
  • Humans
  • Stainless Steel*
  • Surgical Instruments

Substances

  • Stainless Steel