Microbial methods in evaluation of cleaning procedures

Gun Wirtanen, Satu Salo, Tiina Mattila-Sandholm

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review


Cleaning procedures with or without disinfectant treatment for both open and closed systems were used in developing an assessment system based on various microbial methods for detection of residual surface-attached microbes and soil on surfaces after sanitation. The microbial methods tested were cultivation, microscopy using image analysis after staining with acridine orange, viability staining, impedance measurements, viable counts with TTC agar and ATP measurements. Conventional cultivation, combined with impedance measurements and image analysis of surfaces stained with acridine orange gave results that were comparable and complementary. Combination of these methods enabled a total evaluation of both the removal of biofilm and the killing of bacterial cells. Some of the cleaning procedures tested neither removed all of the bacterial cells from the surfaces nor killed the bacteria. The above-mentioned testing protocol can also be used for evaluating the sensitivity of microbial testing methods for use in certain industrial premises.
Original languageEnglish
Title of host publication30th R3-Nordic Contamination Control Symposium
Place of PublicationEspoo
PublisherVTT Technical Research Centre of Finland
ISBN (Print)951-38-5268-7
Publication statusPublished - 1999
MoE publication typeA4 Article in a conference publication
Event30th R3-Nordic Contamination Control Symposium
- Helsinki, Finland
Duration: 30 May 19992 Jun 1999


Conference30th R3-Nordic Contamination Control Symposium

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