Identifying and quantifying ESKAPEE pathogens in and around sinks in high burden hospitals

Area of Science:

• Microbiology
• Infectious Diseases
• Environmental Health

Background:

• Hospital-acquired infections (HAIs) pose a significant threat to patient safety.
• ESKAPEE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp., and Escherichia coli) are major drivers of HAIs.
• Premise plumbing, including sinks and drains, can act as reservoirs for these pathogens, leading to environmental contamination via aerosolization.

Purpose of the Study:

• To quantify viable ESKAPEE pathogens and characterize microbial communities in and around hospital sinks.
• To investigate the role of sinks as a source of microbial contamination in two high-burden hospitals in La Paz, Bolivia.
• To compare microbial contamination levels and community composition between different hospital environments.

Main Methods:

• A prospective observational study was conducted from May to August 2025.
• Surface swabs (n=233) and air samples (n=39) were collected from sink-related areas and room air.
• Samples were analyzed using selective culture media for ESKAPEE identification and quantification (CFU), and 16S rDNA gene sequencing (PacBio Revio) for microbial community analysis.

Main Results:

• Viable presumptive ESKAPEE pathogens were detected in 74.7% of surface swabs and 74.4% of air samples.
• Sink basins showed the highest contamination (mean 31 CFU/100 cm²), with concentrations decreasing away from the drain.
• Klebsiella/Enterobacter spp. were most abundant, while Staphylococcus aureus was most frequently detected (54.4%). Significant hospital-specific differences in contamination and community composition were observed.

Conclusions:

• Hospital sinks serve as a significant reservoir for ESKAPEE pathogens, contributing to environmental contamination.
• The high prevalence of these pathogens underscores the urgent need for targeted infection control measures focusing on sink hygiene.
• Understanding hospital-specific microbial profiles is crucial for developing effective strategies to mitigate HAI risks.