Cleanability of floor surface materials in terms of removal of microorganisms at a low contamination level

Cleanability of 12 different surfaces used for floor coating (3 epoxy resins, 5 polyurethane resins and 4 ceramics with tile's joint) was evaluated as percent removal of adhered bacterial cells or fungal spores. Escherichia coli, Listeria innocua, Pseudomonas aeruginosa, Staphylococcus aureus and Aspergillus niger were separately investigated as markers of hygienic conditions. The Rodac plate technique was employed for the recapture of the microorganisms from the specimens. Distilled water and alkaline detergent were employed as washing solution. All the surfaces contaminated with bacteria, aside from the kind of coating or the presence of tile's joint, proved to be cleanable when the washing operation was done with the alkaline detergent. Besides, in the applied working conditions, the treatment with distilled water showed a high percentage (97 - >99%) of cell the removal for E. coli, L. innocua and P. aeruginosa, whereas it was not sufficient for the complete detachment of S. aureus cells (83 - >99%). In case of contamination with A. niger spores the rate of cleanability decreased either using water (45%) and alkaline detergent (91%). The detachment of microorganisms from synthetic resins was comparable with the one obtained for ceramic materials. Furthermore, the presence of tile's joint on ceramics did not appear to be a preferential point for microbial adhesion. A standardised protocol of contamination and recapture of microorganisms is proposed.