Understanding the individual role of hospital units in the formation of persistent microbial communities, ARG transfer and novel ARG emergence that are ultimately discharged into the urban network.

• Applicant: Professor Dr. Thomas U. Berendonk
• Subject Area: Medical Microbiology and Mycology, Hygiene, Molecular Infection Biology ; Microbial Ecology and Applied Microbiology
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 544004729

Infectious diseases pose an increasing challenge to current health care systems. Specifically, bacterial diseases represent a serious threat because of the increasing levels of antimicrobial resistance observed in the last years. Antimicrobial resistant bacteria (ARB) are not only widespread, they are also often associated with worse outcomes. Among the ARB, β-lactam resistant enterobacteria grouped among pathogens that represent a very high threat to healthcare systems. The detection of ARB pathogens, their sources and the emergence of novel antimicrobial resistance genes (ARGs) are of key relevance in the “antibiotic discovery-void era”. A major contributor to ARG and ARBs is the nosocomial setting. The increased rate of antibiotic treatment compared to the community in addition to the use of last resort drugs such as carbapenems or colistin and longer patient stays promote the selection of both virulent and multi resistant bacteria. Despite the presence of several studies addressing the role of hospitals as sources of ARBs and ARGs in urban waste water (WW), most of them analyse the total hospital effluent or samples that are potentially not independent from each other, in addition these reports focus on the effluent and the fate of ARBs and ARGs after being poured but fail to track the origin of these. Moreover, mixed nosocomial effluents overshadow the role of communities shaped by specific unit discharge (antibiotics, ARGs and pathogens) in ARG transfer and selection. In this project we aim to cover the mentioned knowledge gap in a robust and comprehensive way. Specifically, we aim to shed light on i) the most relevant sources within different hospital units of ARG and community diversity in hospital WW, ii) how is this diversity shaped by the differential pathogen and antimicrobial discharge of specific units and iii) how different microbial communities exposed to different antimicrobial pressure can interact favouring the emergence of novel ARGs with special focus un β-lactamases. For this, we focus our research in Argentina, a country with one of the best health care systems in South America that, on the other hand, is challenged by high antimicrobial consumption and antimicrobial resistance levels. A particular hospital model with individual WW collection tanks for each unit sets this project apart from all previous studies and will be the cornerstone for this uniquely diagrammed project. We consider the planned sampling (inpatient showers, toilettes, basins and WW collection tanks of 5 physically isolated wards) and combination of state-of-the-art techniques (WGS, metagenomics, novel β-lactamase prediction and modelling, massive community analysis and qPCR ARG quantification) with classical microbiology to be the ideal approach to properly answer the posed hypotheses while generating novel insight into a highly concerning topic.

• DFG Programme: Research Grants
• International Connection: Argentina
• Partner Organisation: Consejo Nacional de Investigaciones Científicas y Técnicas
• Co-Investigators: Dr. Uli Klümper; Dr. David Kneis
• Cooperation Partner: Dr. Barbara Ghiglione