title: The degree of bacterial contamination while performing spine surgery.
abstract: METHODS
  Prospective experimental study.
  
  
  OBJECTIVE
  To evaluate bacterial contamination during surgery.
  
  
  BACKGROUND
  The participants of surgery and ventilation system have been known as the most significant sources of contamination.
  
  
  METHODS
  Two pairs of air culture blood agar plate for G(+) bacteria and MacConkey agar plate for G(-) bacteria were placed at 3 different locations in a conventional operation room: in the surgical field, under the airflow of local air conditioner, and pathway to door while performing spine surgeries. One pair of culture plates was retrieved after one hour and the other pair was retrieved after 3 hours. The cultured bacteria were identified and number of colonies was counted.
  
  
  RESULTS
  There was no G(-) bacteria identified. G(+) bacteria grew on all 90 air culture blood agar plates. The colony count of one hour group was 14.5±5.4 in the surgical field, 11.3±6.6 under the local air conditioner, and 13.1±8.7 at the pathway to the door. There was no difference among the 3 locations. The colony count of 3 hours group was 46.4±19.5, 30.3±12.9, and 39.7±15.2, respectively. It was more at the surgical field than under the air conditioner (p=0.03). The number of colonies of one hour group was 13.0±7.0 and 3 hours group was 38.8±17.1. There was positive correlation between the time and the number of colonies (r=0.76, p=0.000).
  
  
  CONCLUSIONS
  Conventional operation room was contaminated by G(+) bacteria. The degree of contamination was most high at the surgical field. The number of bacteria increased right proportionally to the time.
authors.affiliation: Department of Orthopedic Surgery, Seoul Sacred Heart General Hospital, Seoul, Korea.
authors.forename: Dong Ki
authors.initials: DK
authors.lastname: Ahn
authors.forename: Hoon Seok
authors.initials: HS
authors.lastname: Park
authors.forename: Tae Woo
authors.initials: TW
authors.lastname: Kim
authors.forename: Jong Hwa
authors.initials: JH
authors.lastname: Yang
authors.forename: Kyung Hwan
authors.initials: KH
authors.lastname: Boo
authors.forename: In Ja
authors.initials: IJ
authors.lastname: Kim
authors.forename: Hye Jin
authors.initials: HJ
authors.lastname: Lee
keywords: Bacterial contamination; Source of contamination; Surgical site infection