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Safe measurements to prevent the transmission of (multidrug-resistant) mycobacteria such as disinfection are essential in healthcare settings. In Europe chemical disinfectants are tested for their tuberculocidal and mycobactericidal efficacy by the internationally accepted test procedure described in EN 14348. However, especially for amine-based disinfectants, invalid results may occur by this procedure due to insufficient neutralization. In this multi-laboratory study the procedure described in EN 14348 was optimized by a combination of chemical neutralization and membrane filtration in order to obtain a valid and secure method especially for amine-based disinfectants., (Copyright © 2021 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.)

Background: Since the first appearance of Candida auris in 2009, this yeast has become a relevant pathogen in the clinical field. C. auris has been detected on various surfaces in health facilities, and is therefore a target for appropriate disinfection procedures. Preventive measures have to be implemented based on disinfectants with proven efficacy against C. auris., Aim: The chemical tolerance of C. auris was compared with the surrogate test organism Candida albicans as established in the European standards (EN). In this way, conclusions will be drawn as to whether the disinfectants tested according to EN 13624 and EN 16615 are at least equally effective against C. auris., Methods: The chemical susceptibility of C. auris and C. albicans was investigated using standardized EN test protocols. EN 13624 and EN 16615 were used in this study to examine two commercially available surface disinfectants based on alcohol and quaternary ammonium compounds (QACs), respectively. In addition, the survival rates of the two yeast species were studied on a defined test surface simulating practical conditions., Findings: In comparison with C. albicans, C. auris was found to be significantly more susceptible to the alcohol- and QAC-based disinfectants used in this study. C. albicans was found to be more tolerant to drying on the test surface in EN 16615, yielding higher recovery rates., Conclusion: C. albicans is a suitable surrogate test organism when targeting yeasticidal efficacy, which, based on EN 13624 and EN 16615, includes efficacy against the human pathogen C. auris., (Copyright © 2020 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.)

Background: A rapid test system using fluorescent Mycobacterium terrae to evaluate the tuberculocidal efficacy of disinfectants has recently been published. Results were obtained in a significantly shorter time than was previously possible., Aim: To compare the European Standard test system with the fluorescence assay and to validate the rapid test system, including particularly the quantitative suspension test., Methods: Quantitative suspension tests and quantitative carrier tests were carried out according to EN 14348 and EN 14563, respectively. Quantitative carrier tests and subsequent green fluorescent protein (GFP)-based determination of germicidal efficacy were carried out as described previously. A peracetic acid-based formulation was used as a test germicide., Findings: Testing of the germicide in the quantitative suspension test EN 14348 and in the quantitative carrier test EN 14563 revealed tuberculocidal efficacy at a concentration of 1% after 15 min contact time. Accordingly, data obtained from the fluorescence assay demonstrated that a germicide concentration of 1% was effective after 15 min, indicating no live mycobacteria following this treatment. Thus, identical in-use parameters for tuberculocidal efficacy were obtained either by applying the quantitative suspension and quantitative carrier tests EN 14348 and EN 14563 or by using the GFP-based rapid test system., Conclusion: The GFP-based rapid test system compares well with the established European Standard test procedure including both phase 2, step 1 and phase 2, step 2 tests and provides a rapid and sensitive tool for testing germicides for relevant in-use concentrations and contact times., (Copyright © 2019 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.)