5.1 The quantity and quality of the spores produced by this practice may be used to assess environmental surface disinfectants for sporicidal activity (4). The method is applicable to standard as well as clinically isolated toxigenic and non-toxigenic strains of C. difficile.

1.1 This practice describes the production and semipurification of C. difficile spores (also called endospores) primarily for use in testing the sporicidal activities of environmental surface disinfectants (Test Methods E2111and E2197); such spores can also be used to study their structure, chemistry and germination.

1.2 While the practice described is based on the use of 500-mL volumes of the liquid culture medium in an anaerobic incubator, anaerobic jars with smaller volumes of the same medium can also be used.

1.3 It is the responsibility of the investigator to determine whether Good Laboratory Practice (GLP) regulations are required and to follow them when appropriate (40 CFR, Part 160 for EPA submissions and 21 CFR; Part 58 for FDA submissions).

1.4 Warning—This standard may involve hazardous materials, chemicals, and microorganisms and should be performed only by persons with formal training in microbiology.

1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.