Fig. 3
Pathogen contamination in enrolled trains. Surfaces (floor, door, handrails, and seats) and air filters were sampled using RODAC plates. Assayed pathogens included Staphylococcus spp., Enterobacteriaceae spp., Pseudomonas spp., Clostridium spp., Candida spp., and Aspergillus spp. a Contamination levels in tested surface (floors, seats, handrails, and doors) and air filter samples. Results are expressed as median values of CFU/m2 ± S.D. b Prevalence of assayed pathogens in total surface and air samples. Results are expressed as median values of CFU/m2 ± S.D. Values on the left Y axis refer to Staphylococcus spp., whereas values on the right Y-axis refer to the other microbes. c, d Pathogenic contamination levels before (T0) and after (T1–T5) the introduction of PCHS sanitation on surfaces (c) and air filters (d). The results are expressed as CFU/m2: median values (lower part of the box) and Q3 values (upper part of the box, representing the 75% percentile values) are shown, together with min and max values. e, f Comparison between the median levels of contamination detected in the control train (CTR), normalized to 100%, and those detected in the PCHS-train, expressed as percentage values of PCHS train versus the number of CFU/m2 detected in the control train, taken as 100%