Background: Biofilm removal is a challenge during surgical instrument processing. We analyzed the time required for Staphylococcus epidermidis to form biofilms on surgical instruments, and how cleaning methods removed them.
Methods: Different areas (ratchet, shank, and jaw) of straight crile forceps were contaminated by soaking in Tryptic Soy Broth containing 106 colony forming units (CFU)/mL of S epidermidis for 1, 2, 4, 6, 8, and 12 hours. S epidermidis adhesion and removal, after manual or automated ultrasonic cleaning, was evaluated by microbiological culture and scanning electron microscopy.
Results: Microbial load increased with time (101-102 CFU/cm2 after 1 hour; 104 CFU/cm2 after 12 hours). Exopolysaccharide was detected after 2 hours and gradually increased thereafter. Bacterial load was reduced by 1-2 log10 after manual cleaning and 1-3 log10 after automated cleaning, but biofilms were not completely eliminated. In general, bacterial load was lower in shank fragments. This difference was significant at 6 hours.
Conclusions: Rapid adhesion of S epidermidis and exopolysaccharide formation was observed on surgical instruments. Automated cleaning was more effective than manual cleaning, but neither method removed biofilms completely. The precleaning conditions and the forceps design are critical factors in processing quality.
Keywords: Biofilm; Cleaning; Infection control; Medical device reprocessing; Patient safety; Surgical instrument.
Copyright © 2019 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.