Evaluation of bacterial survival on inert surfaces in a hyperbaric environment

Introduction: Surface cleaning and hand hygiene within hyperbaric chambers are challenging because of the risk of fire with currently used products containing alcohol or glycerine. This study aimed to investigate if hyperbaric conditions could have inhibitory effects on bacteria present on inert materials. Methods: We deposited Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) on inert materials in an experimental chamber (Comex1200Alu) and compressed the chamber environment with air (253 kPa, 95 minutes) (referred to as indoor). The control was contaminated materials placed outside the chamber (referred to as outdoor). We chose inert materials including plastic, metal, and seat upholstery (imitation leather). We measured bacterial growth and survival and compared the groups using a Student’s t-test. Results: Regardless of the surface types tested, there were no significant differences in bacterial reduction between indoor and outdoor conditions for either E. coli or S. aureus and any of the materials (P > 0.05). Conclusions: We found that pressurised air (253 kPa for 95 minutes) has neither proliferative nor bactericidal action on S. aureus and E. coli colonies deposited on inert surfaces compared to those present outside a hyperbaric chamber in normobaric air conditions.