Background: A surgical instrument can have areas that pose different challenges to cleaning, hindering the removal of dirt. This can directly impact the effectiveness of its processing while potentially promoting cross contamination. Moreover, structural changes (ie, cracks or fissures) on the instrument surface, although rarely addressed, can act as reservoirs for microorganisms, contributing to organic matter retention, microbial growth, and biofilm formation. Our aim was to determine the effect of irregularities in the microstructure of surgical instruments on microbial adherence. Methods: We analyzed 18 fragments of 3 distinct areas of new crile forceps: the ratchet, shank, and jaw. Of these fragments, 15 were artificially contaminated by immersion in tryptic soy broth containing 10 6 CFU/mL of Escherichia coli (ATCC 25922), for 4, 6, 8, and 12 hours of incubation at 37C with agitation at 100 rpm. The other 3 fragments were used as controls. All fragments were subjected to scanning electron microscopy to evaluate the adhesion of the microorganism. Results: An irregular surface was found in 3 of 6 shank fragments (50%) (Fig. 1) and in all the jaw and ratchet fragments, grooves, and cracks. Initially, there was less adherence of E. coli to the smooth shank surface after contamination, but the concentration of the microorganism increased progressively over time in relation to that in the jaw or ratchet at the same time, and a higher concentration occurred in the cracks and grooves. Conclusions: Structural damage was observed in all fragments, especially in the ratchet and jaw areas, favoring microbial accumulation. Microorganisms housed in the cracks and grooves were better protected from removal by scrubbing with a brush (being unlikely to reach them), making these areas a microbial reservoir and source of contamination. Prolonged contact of the instrument with the contaminating microorganism allowed for greater adherence, even on the smooth areas. The results support the relevance of the early onset of cleaning, considering that even microscopic changes on the surface of the instrument may represent an additional challenge to its effective processing.

Funding: None

Disclosures: None