Characterising the Hospital Microbiota: A Descriptive Study of Environmental Monitoring

The hospital environment is widely recognised as a source of microorganisms that collectively constitute the so-called “hospital microbiota”. The aim of this study was to investigate this microbiota, providing as accurate a picture as possible of the actual level of environmental contamination within the hospital. We conducted a 2-year surveillance study in a large acute-care hospital to map the microbiological profiles of the various wards and identify areas requiring improvement. The analysis revealed substantial contamination of surfaces by ESKAPEE microorganisms, well-known causes of healthcare-associated infections. Near-patient surfaces and some critical items such as IV poles, medication carts, and infusion pumps, were found to be contaminated. Among wards, the highest level of contamination was found in the medical area, followed by emergency and surgical wards. A substantial amount of antibiotic-resistant microorganisms was detected, including methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, multidrug-resistant Acinetobacter baumannii and carbapenem-resistant Enterobacteriaceae. The presence of these microorganisms on particularly critical surfaces and in critical wards poses a serious risk. Monitoring environmental contamination could help identify critical issues and assess the necessity of improving environmental disinfection protocols in addition to the well-known procedures for preventing healthcare-associated infections.