Microorganisms are everywhere, bacteria and fungi contaminate our body, our houses, workplaces, pets and the whole environment. Fortunately, among many billions of bacteria, only 1,500 can be dangerous for our health, causing different diseases such as pneumonia or skin infections. The real problem is that the number of bacterial strains which develop resistances towards disinfectants and especially antibiotics is increasing very fast. Some of these resistant microorganisms are difficult to destroy and can survive for a longer time on the floor and other surfaces.