Alberta Vandini

Impact of a Probiotic-Based Cleaning Intervention on the Microbiota Ecosystem of the Hospital Surfaces: Focus on the Resistome Remodulation.

Background Contamination of hospital surfaces by clinically-relevant pathogens represents a major concern in healthcare facilities, due to its impact on transmission of healthcare-associated infections (HAIs) and to the growing drug resistance of HAI-associated pathogens. Routinely used chemical disinfectants show limitations in controlling pathogen contamination, due to their inefficacy in preventing recontamination and selection of resistant strains. Recently we observed that an innovative approach, based on a cleanser added with spores of non-pathogenic probiotic Bacilli, was effective in stably counteracting the growth of several pathogens contaminating hospital surfaces. Methods Here, we wanted to study the impact of the Bacillus-based cleanser on the drug-resistance features of the healthcare pathogens population. In parallel, the ability of cleanser-derived Bacilli to infect hospitalized patients was also investigated. Results Collected data showed that Bacilli spores can germinate on dry inanimate surfaces, generating the bacterial vegetative forms which counteract the growth of pathogens and effectively substitute for them on treated surfaces. Strikingly, this procedure did not select resistant species, but conversely induced an evident decrease of antibiotic resistance genes in the contaminating microbial population. Also importantly, all the six HAI-positive patients hosted in the treated areas resulted negative for probiotic Bacilli, thus adding evidences to their safety-to-use. Conclusions These results indicate that this probiotic-based procedure is active not only in controlling surface microbial contamination but also in lowering drug-resistant species, suggesting that it may have relevant clinical and therapeutical implications for the management of HAIs.

Hard surface biocontrol in hospitals using microbial-based cleaning products.

Background Healthcare-Associated Infections (HAIs) are one of the most frequent complications occurring in healthcare facilities. Contaminated environmental surfaces provide an important potential source for transmission of many healthcare-associated pathogens, thus indicating the need for new and sustainable strategies. Aim This study aims to evaluate the effect of a novel cleaning procedure based on the mechanism of biocontrol, on the presence and survival of several microorganisms responsible for HAIs (i.e. coliforms, Staphyloccus aureus, Clostridium difficile, and Candida albicans) on hard surfaces in a hospital setting. Methods The effect of microbial cleaning, containing spores of food grade Bacillus subtilis, Bacillus pumilus and Bacillus megaterium, in comparison with conventional cleaning protocols, was evaluated for 24 weeks in three independent hospitals (one in Belgium and two in Italy) and approximately 20000 microbial surface samples were collected. Results Microbial cleaning, as part of the daily cleaning protocol, resulted in a reduction of HAI-related pathogens by 50 to 89%. This effect was achieved after 3–4 weeks and the reduction in the pathogen load was stable over time. Moreover, by using microbial or conventional cleaning alternatively, we found that this effect was directly related to the new procedure, as indicated by the raise in CFU/m2 when microbial cleaning was replaced by the conventional procedure. Although many questions remain regarding the actual mechanisms involved, this study demonstrates that microbial cleaning is a more effective and sustainable alternative to chemical cleaning and non-specific disinfection in healthcare facilities. Conclusions This study indicates microbial cleaning as an effective strategy in continuously lowering the number of HAI-related microorganisms on surfaces. The first indications on the actual level of HAIs in the trial hospitals monitored on a continuous basis are very promising, and may pave the way for a novel and cost-effective strategy to counteract or (bio)control healthcare-associated pathogens.

Experimental evaluation of the efficacy of sanitation procedures in operating rooms.

BACKGROUND There remains much debate on how to define an adequate sanitation protocol in hospital environments. METHODS The efficacy of a sanitation protocol in the operating room (OR) of a modern hospital was evaluated by measuring bacterial load on different types of finishing materials of all internal surfaces (ie, walls, floors, and furnishings). Samples were obtained before cleaning and over the subsequent 24 hours. A total of 2124 microbiological samples were collected using RODAC plates and sterile swabs. RESULTS The data demonstrate a very significant postsanitation reduction of bacterial load on floors and furnishings; however, no significant data on walls were obtained, because of the low levels of initial contamination (1.50 to 5.98 cfu/100 cm2). The increase in postsanitation bacterial load over time was greater on smooth materials than on porous materials, on which a further reduction in contamination was seen. The study outcomes were confirmed by simulation experiments in which different materials were contaminated with a predetermined bacterial load and then subjected to the sanitation protocol. These simulation experiments were carried out both in vitro and in an eddy-flux testing room that simulated a full-scale OR similar (in terms of architectonic systems) to a real setting. CONCLUSION Our data demonstrate that the spatial (vertical/horizontal) disposition of materials affects the initial contamination level, which is always much lower on vertical surfaces than on horizontal ones. Moreover, postsanitation bacterial load recovery is dependent on the physical properties of the surface.