Hospital wastewater systems: origins of novel nosocomial bacteria
Date: December 7th, 2023
Time: 10:30 am PST
Speaker: Professor Colum Dunne, School of Medicine, University of Limerick, Ireland
Hospital-acquired infection (HAI) is a challenge globally, often associated with incidence of infectious agents exhibiting antimicrobial resistance (AMR). Internationally, there are numerous publications describing outbreaks of nosocomial infections, typically providing characterisation of recognised microorganisms, their antimicrobial susceptibilities and details of infection prevention and control (IPC) interventions. Environmental patient-facing wastewater (WW) apparatus such as handwashing sinks, showers and toilets are identified frequently as the sources of these infectious agents and associated AMR genes (ARGs). We have undertaken a large-scale metagenomic analysis of the WW system in a large teaching hospital in the Republic of Ireland that has experienced ongoing multidrug-resistant HAI outbreaks. Diverse taxonomic and resistome profiles were observed across all pipe sections studied, with members of phyla Proteobacteria and Actinobacteria dominating. The highest numbers of ARGs observed were those encoding resistance to tetracyclines, fluoroquinolones, diaminopyrimidines, β-lactams, and macrolides, all of which are significant clinically and are commonly used antibiotic classes. These unique large-scale analyses reinforce the need for regular decontamination of patient-facing hospital WW pipes and effective infection control policies to prevent the transmission of nosocomial infection and emergence of AMR within potential WW reservoirs.