Reduction of the microbiological load on hospital surfaces through probiotic-based cleaning procedures: A new strategy to control nosocomial infections

Traditional chemical disinfectants used in cleaning procedures in hospitals display several disadvantages such as limited in time biocide action, rapid bacterial re-contamination of treated surfaces, development of multidrug resistance by microorganisms (although so far demonstrated only in vitro) environmental pollution and potential onset of chemical sensitivity in patients, workforce and cleaners. According to recent experimental studies, cleaning techniques based on microbial bio-stabilization by using probiotic-based products are promising. This study was aimed to evaluate the efficacy of a new procedure of sanitation with cleaning products containing spore forms of Bacillus spp, in comparison with a traditional chlorine-based treatment. Results from in vitro data, obtained under contamination-controlled conditions, prompted us to conduct an experimental study within two wards and outpatient departments in a study-model hospital. The total microbial count as well as Staphylococcus aureus, Coliforms, Pseudomonas spp., and Candida spp. titers were monitored for 4 months on several surfaces. A total of 11.223 microbiological samples were collected, both 7 and 24 hours after the scheduled cleaning procedures, setting the pre-cleaning microbial load as a control parameter. Our data showed that, differently from traditional chemical-based disinfectants, the effect of the probiotic-based product led to a significant reduction (>80%) of the microbial load of Staphylococcus aureus, Coliforms, Pseudomonas spp. and Candida spp., with a stable effect over time. Data obtained in the present study show that probiotic-based detergents significantly reduce the presence of pathogenic bacteria on contaminated surfaces, and support the hypothesis of a mechanism mediated by bio-stabilization of the microbial load.