Purpose: Antimicrobial resistance (AMR) is one of the major threats to human health, and the high frequency of resistant pathogens in the hospital environment can contribute to the transmission of difficult-to-treat health care-associated infections (HAIs). We recently reported that, compared with conventional chemical cleaning, the use of a microbial-based sanitation strategy (Probiotic Cleaning Hygiene System [PCHS]) was associated with remodulation of hospital microbiota and reduction of HAI incidence. Here, we aimed to analyze the impact of PCHS on AMR and related effects, such as HAI-associated antimicrobial drug consumption and costs. Patients and methods: Five Italian hospitals, enrolled in a multicenter study where conventional sanitation methods were replaced with PCHS, were included in the analysis. The study period included a 6-month observation for each sanitation type. Surface microbiota AMR was analyzed using microarray, nested PCR, antibiogram, and microdilution tests. Drug consumption data and related costs were obtained from the medical records of all hospitalized patients affected by HAIs. Results: PCHS use was associated with up to 99% decrease of the AMR genes harbored by surface hospital microbiota, independently of the resistance types originally present in each individual setting (P_c<0.01). Functional assays confirmed the molecular data, demonstrating a 33%–100% decrease of resistant strains depending on the antibiotic type. Antimicrobial drug consumption associated with HAI onset showed a global 60.3% decrease, with a 75.4% decrease of the associated costs. Conclusion: The spread of AMR in the hospital environment can be limited by the use of sanitation methods to remodulate the hospital microbiota, leading to lower antimicrobial consumption and costs. This approach might be considered as part of broader infection prevention and control strategies.

Indoor air quality (IAQ) plays a vital role in supporting both the physical and mental well-being of individuals in enclosed spaces, and the role of mechanical ventilation systems has gained increasing attention due to building design’s focus on energy efficiency and thus airtight constructions. This study investigated the pre–post effects of installing a heat recovery mechanical ventilation system (MVHR) on indoor air quality in a high school classroom in Ferrara, Italy. The analysis focused on experimental measurements of temperature (T), relative humidity (RH), and carbon dioxide (CO₂) both inside and outside the same classroom, which had constant occupancy (17 students) for an entire school year, allowing a comparison between natural and mechanical ventilation. With a comprehensive approach, particulate matter (PM_2.5), volatile organic compounds (VOCs), and radon levels (Rn) were monitored as well, after the installation of the MVHR. By comparing natural and mechanical ventilation, the study highlights the strengths and limitations of the ventilation system implemented, together with an evaluation of the system’s energy consumption, including a 2 kW post-heating battery. In terms of results, the MVHR demonstrated clear benefits in managing CO₂ levels and improving sensory, olfactory, and psychophysical well-being, as well as the attention levels of students. In detail, under natural ventilation, peak concentrations exceeded 4500 ppm, while mechanical ventilation kept them below 1500 ppm. The average CO₂ concentration during occupancy dropped from 2500 ppm to around 1000 ppm, achieving a 62% reduction. However, beneficial effects were not observed for other parameters, such as PM_2.5, VOCs, or radon. The latter displayed annual average values around 21 Bq/m³ and peaks reaching 56 Bq/m³.

The poultry industry is facing the growing need to decrease the use of antibiotics to prevent increasing antimicrobial resistance (AMR). Toward this aim, probiotics and bacteriophages have been suggested as an alternative to antibiotics to reducing Salmonella in broilers, which poses risks to food safety and public health. Previous results showed that selected Bacillus probiotics can significantly limit broiler contamination, and anti-Salmonella phages are already available in the US and EU. However, a comprehensive evaluation of the impact of probiotics and phages on commercial poultry farms is still lacking. To this aim, a pre-post study was conducted in a poultry farm experiencing recurrent Salmonella outbreaks, to assess the anti-Salmonella effectiveness of a combined probiotic-phage approach. The study included two complete rearing cycles: T1, conducted in standard conditions and used as a control, and T2, when probiotics and phages were applied. Salmonella monitoring was performed in both the environment and broilers throughout the study periods, showing a significant 90 % decrease in Salmonella presence in T2 compared to T1 cycle (P ≤ 0.001). The decrease was observed at both the environmental and animal (caeca) levels. Notably, the whole broiler caecal microbiome was modified in T2 compared to T1 broilers, evidencing a significant increase in biodiversity accompanied by an earlier appearance of Ruminococcus, Clostridium, and Faecalibacterium genera. In parallel, broiler mortality was reduced by 72 % and broiler weight was increased by 6.4 % in T2 vs. T1 broilers (P ≤ 0.01). The findings indicate that a combined probiotic/phage approach could be a promising strategy to combat the Salmonella burden, while reducing the requirement for antibiotics and improving broiler health.