title: Human skin flora as a potential source of epidural abscess.
abstract: BACKGROUND
  The mechanism of epidural infection associated with epidural block is not clearly understood. Resident organisms in skin specimens were studied after skin was prepared with disinfectants.
  
  
  METHODS
  Sixty-nine paired skin specimens were excised at incisional sites after skin disinfection with 10% povidone-iodine (10% PVP-I) or 0.5% chlorhexidine in 80% ethanol (0.5% CHE) from 60 patients having back surgery. One of the specimen pairs was placed in 10 ml brain-heart infusion broth and incubated in air at 37 degrees C for 96 h. The other specimen was sectioned at 3 microns and prepared with Gram's stain for examination with the microscope.
  
  
  RESULTS
  Thirteen gram-positive staphylococcal species (Staphylococcus epidermidis, 69.2%; S. hyicus, 15.4%; and S. capitis, 15.4%) were isolated from cultures. The isolates were found in a significantly greater proportion of the skin specimens disinfected with 10% PVP-I than in those disinfected with 0.5% CHE (11 of 34 cultures [32.4%] vs. 2 of 35 cultures [5.7%]; P < 0.01). Many gram-positive cocci were observed with the microscope in 4 (11.8%) and 5 (14.3%) of 34 and 35 skin specimens disinfected with 10% PVP-I and 0.5% CHE, respectively. The cocci formed a dense colony in each follicle and in the stratum corneum. No organism was present in any of 17,584 sweat glands examined.
  
  
  CONCLUSIONS
  In a large proportion of patients, isolation of viable organisms from excised skin specimens after disinfection with 10% PVP-I suggests that contamination of the epidural space by the skin flora may be a potential mechanism of epidural infection associated with epidural block.
authors.affiliation: Department of Anesthesiology, School of Medicine, Fukuoka University, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Sato
authors.forename: T
authors.initials: T
authors.lastname: Sakuragi
authors.forename: K
authors.initials: K
authors.lastname: Dan
mesh_terms: D000038:Abscess / Q000382:microbiology / Q000517:prevention & control*; D000767:Anesthesia, Epidural / Q000009:adverse effects*; D000891:Anti-Infective Agents, Local / Q000627:therapeutic use*; D001415:Back / Q000601:surgery; D002710:Chlorhexidine / Q000627:therapeutic use*; D000431:Ethanol / Q000627:therapeutic use*; D006801:Humans; D011206:Povidone-Iodine / Q000627:therapeutic use*; D012867:Skin / Q000187:drug effects / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification*; D013212:Staphylococcus epidermidis / Q000187:drug effects / Q000302:isolation & purification*
chemical_list: D000891:Anti-Infective Agents, Local; D000431:Ethanol; D011206:Povidone-Iodine; D002710:Chlorhexidine