title: Development of a sporicidal test method for Clostridium difficile.
abstract: BACKGROUND
  Disinfectants with claimed activity against Clostridium difficile must be evaluated to ensure efficacy against the spores that comprise an environmental source of patient infection. Unfortunately there is, at present, no generally accepted method for evaluating these disinfectants. In the absence of such a method, laboratories have to adapt protocols that were not designed for products used in medical environments and consequently may use inappropriate test organisms, exposure times, and pass criteria.
  
  
  OBJECTIVE
  To develop and evaluate a method for testing the activity of disinfectants against C. difficile spores using exposure times and pass criteria which are relevant to clinical application.
  
  
  METHODS
  A Joint Working Party of the Healthcare Infection Society (HIS) and the Advisory Committee on Antimicrobial Resistance and Healthcare Associated Infections (ARHAI) of the Department of Health in England was assembled. The Working Party adapted a previously described enzyme-based method for spore purification (the Clospore method) using an exposure time of 5 min and a 5 log10 kill as a pass criterion.
  
  
  RESULTS
  Evaluation of the method by three laboratories demonstrated that the method is simple to follow and that the results are repeatable and reproducible.
  
  
  CONCLUSIONS
  The method described by the Working Party produces a clean suspension with a high titre of spores. It is recommended that, for a disinfectant used in the environment, the product should demonstrate a 5 log10 reduction in 5 min under clean or dirty conditions to fulfil the requirements of the test.
authors.affiliation: Hospital Infection Research Laboratory, Queen Elizabeth Hospital, Birmingham, UK. Electronic address: adam.fraise@uhb.nhs.uk.
authors.forename: A P
authors.initials: AP
authors.lastname: Fraise
authors.affiliation: Hospital Infection Research Laboratory, Queen Elizabeth Hospital, Birmingham, UK.
authors.forename: M A C
authors.initials: MA
authors.lastname: Wilkinson
authors.affiliation: Hospital Infection Research Laboratory, Queen Elizabeth Hospital, Birmingham, UK.
authors.forename: C R
authors.initials: CR
authors.lastname: Bradley
authors.affiliation: Public Health England, Porton Down, Wiltshire, UK.
authors.forename: S
authors.initials: S
authors.lastname: Paton
authors.affiliation: Public Health England, Porton Down, Wiltshire, UK.
authors.forename: J
authors.initials: J
authors.lastname: Walker
authors.affiliation: School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK.
authors.forename: J-Y
authors.initials: JY
authors.lastname: Maillard
authors.affiliation: School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK.
authors.forename: R L
authors.initials: RL
authors.lastname: Wesgate
authors.affiliation: Public Health England, Colindale, London, UK.
authors.forename: P
authors.initials: P
authors.lastname: Hoffman
authors.affiliation: Scottish Microbiology Reference Laboratories, Glasgow, UK.
authors.forename: J
authors.initials: J
authors.lastname: Coia
authors.affiliation: BluTest Laboratories Ltd, Glasgow, UK.
authors.forename: C
authors.initials: C
authors.lastname: Woodall
authors.affiliation: Department of Health in England, London, UK.
authors.forename: C
authors.initials: C
authors.lastname: Fry
authors.affiliation: Department of Microbiology, University of Leeds, Leeds, UK.
authors.forename: M
authors.initials: M
authors.lastname: Wilcox
mesh_terms: D016360:Clostridioides difficile / Q000187:drug effects*; D004202:Disinfectants / Q000494:pharmacology*; D004739:England; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods*; D050296:Microbial Viability / Q000187:drug effects*; D013171:Spores, Bacterial / Q000187:drug effects*
chemical_list: D004202:Disinfectants
keywords: Clostridium difficile; Disinfectant; Testing