title: Microbial contamination of surgical instruments used for laparotomy.
abstract: 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, gram-positive cocci were dominant [corrected]. 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.
  
  
  CONCLUSIONS
  Surgical instruments tend to be contaminated during operations by microbes that inhabit the skin and organs. Surgical instruments could act as fomites for the pathogens of surgical site infection even if the surgical field is not apparently contaminated, through application of appropriate practices adhering to surgical site infection guidelines.
authors.affiliation: Surgical Center, The University of Tokyo Hospital, Tokyo, Japan; Division of Infection Prevention and Control, Tokyo Healthcare University Postgraduate School, Tokyo, Japan. Electronic address: saitoyu-nur@h.u-tokyo.ac.jp.
authors.forename: Yuhei
authors.initials: Y
authors.lastname: Saito
authors.affiliation: Division of Infection Prevention and Control, Tokyo Healthcare University Postgraduate School, Tokyo, Japan.
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Kobayashi
authors.affiliation: Surgical Center, The University of Tokyo Hospital, Tokyo, Japan.
authors.forename: Yushi
authors.initials: Y
authors.lastname: Uetera
authors.affiliation: Surgical Center, The University of Tokyo Hospital, Tokyo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yasuhara
authors.affiliation: Division of Infection Prevention and Control, Tokyo Healthcare University Postgraduate School, Tokyo, Japan; Research and Development Division, Yoshida Pharmaceutical Co, Ltd, Tokyo, Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Kajiura
authors.affiliation: Division of Infection Prevention and Control, Tokyo Healthcare University Postgraduate School, Tokyo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Okubo
mesh_terms: D001419:Bacteria / Q000145:classification / Q000302:isolation & purification*; D015169:Colony Count, Microbial; D050456:Fomites / Q000382:microbiology*; D006801:Humans; D007813:Laparotomy; D013525:Surgical Instruments / Q000382:microbiology*
keywords: Aseptic technique; Endogenous flora; Intraoperative contamination; Sterilization; Surgical site infections