PhD defence A.S. (Anja) van der Schoor

Below is a brief summary about the dissertation:

Multidrug-resistant microorganisms (MDRO) are increasing worldwide and are leading to increased healthcare costs, morbidity, and mortality (1, 2). They are a frequent source of healthcare-associated infections (HAI), hindering antimicrobial treatment (3). HAI can have an endogenous source, i.e., body sites such as the skin, or an exogenous source, e.g., the hospital environment, its surfaces, or healthcare workers. This thesis focused on endogenous sources by screening patients upon admission to the hospital, and on exogenous sources, specifically the hospital environment, of MDRO and Staphylococcus aureus. We aimed to determine the effect of transitioning to a newly constructed hospital with 100% single-occupancy rooms and private bathrooms on the microbial safety of the hospital. We consider the microbial safety of the new hospital as improved when the environmental contamination in general and/or with MDRO is lower, and/or when the acquisition and/or transmission of MDRO is lower compared to the old hospital. The studies in this thesis were divided into patient related and environmental related research. In the patient related research chapter (Chapter 2), we determined the effect on acquisition of ESBL-E (Chapter 2.1). Additionally, we aimed to determine screening methods to identify patients colonized with MDRO upon admission (Chapter 2.2 and Chapter 2.3). Furthermore, we aimed to determine the dynamics between patients and the hospital environment for Staphylococcus aureus (Chapter 2.4). In the environmental related research chapter (Chapter 3), we performed a survey to determine current sampling practices throughout Europe (Chapter 3.1). Finally, we determined the effect of the new environment, i.e., single rooms, on environmental contamination of the patient room and bathroom (Chapter 3.2).