Microbial contamination of surgical instruments used for laparotomy

Background: The aim of this study was to determine the risk of contamination of surgical instruments according to the type of instrument and the surgical procedure. Methods: Microbiologic examination was conducted on 140 pairs of forceps used in 24 elective laparotomies. These included 60 pairs of tissue forceps and 80 pairs of DeBakey forceps. Microbes on their surface were recovered using a membrane filter method. Adenosine triphosphate assay was also performed simultaneously in each pair of forceps. Results: A total of 66 strains of microbes was recovered from 44 collected instruments (31%), with microbial counts ranging from 0 to 296 colony-forming units. Among the recovered microbes, gramnegative cocci were dominant. The remaining microbes included 6 strains of gram-positive rods and 4 strains of gram-negative rods. The most common organism was Staphylococcus epidermidis, followed by S hominis and S warneri. Residual adenosine triphosphate was not correlated with the number of recovered microbes. Conclusion: Surgical instruments tend to be contaminated during operations by microbes that inhabit