title: Duodenoscope reprocessing surveillance with adenosine triphosphate testing and terminal cultures: a clinical pilot study.
abstract: OBJECTIVE
  Recent reports of infectious outbreaks linked to duodenoscopes have led to proposals for duodenoscope surveillance culturing, which has inherent limitations. We aimed to assess the feasibility of real-time adenosine triphosphate (ATP) testing after manual cleaning and its ability to predict reprocessing adequacy, as determined by terminal duodenoscope cultures.
  
  
  METHODS
  Clinically used duodenoscopes underwent reprocessing per current guidelines. After manual cleaning, ATP samples were obtained from the elevator, within the proximal biopsy port, and by flushing of the biopsy channel. After high-level disinfection (HLD), aerobic cultures of the elevator and biopsy channel were obtained using sterile technique. Duodenoscopes with any ATP sample ≥200 relative light units underwent repeated cycles of cleaning, ATP testing, HLD, and terminal culturing.
  
  
  RESULTS
  Twenty clinically used duodenoscopes were included; 18 underwent a second reprocessing cycle, and 6 underwent a third reprocessing cycle because of detection of high ATP. After the initial reprocessing cycle, 12 of 20 (60%) duodenoscopes had positive culture results, most commonly yielding gram-negative bacilli (GNB, n = 11 from 9 duodenoscopes), and catalase-positive gram-positive cocci (CP-GPC, n = 7 from 7 duodenoscopes), suggesting staphylococcal organisms. Ambient environmental controls also showed GNB and CP-GPC growth. The overall sensitivity and specificity of ATP testing compared with terminal cultures were 30% and 53%, respectively.
  
  
  CONCLUSIONS
  ATP sampling appears to correlate poorly with terminal culture results and cannot be recommended as a surrogate for terminal cultures. The performance and interpretation of cultures remains complicated by the potential recovery of environmental contaminants.
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Kavel
authors.initials: K
authors.lastname: Visrodia
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Hanada
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Kelly M
authors.initials: KM
authors.lastname: Pennington
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Pritish K
authors.initials: PK
authors.lastname: Tosh
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Topazian
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Bret T
authors.initials: BT
authors.lastname: Petersen
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis*; D001431:Bacteriological Techniques; D002374:Catalase / Q000378:metabolism; D004203:Disinfection / Q000592:standards*; D020698:Duodenoscopes / Q000382:microbiology*; D004866:Equipment Contamination; D005240:Feasibility Studies; D006090:Gram-Negative Bacteria / Q000302:isolation & purification; D006095:Gram-Positive Cocci / Q000201:enzymology / Q000302:isolation & purification; D017408:Guidelines as Topic; D010865:Pilot Projects; D012680:Sensitivity and Specificity
chemical_list: D000255:Adenosine Triphosphate; D002374:Catalase