Effectiveness of steam cleaning technology on reducing the occurrence of ESKAPE organisms and Escherichia coli in the stables of an equine referral hospital.

Overview

• This study assessed how effective steam cleaning is in decreasing the presence of multidrug-resistant “ESKAPE” bacteria and Escherichia coli on surfaces within an equine referral hospital’s stables.
• The study found that steam cleaning significantly reduced these organisms on smooth surfaces, suggesting it may be a useful, eco-friendly alternative to chemical disinfectants.

Background

• ESKAPE Organisms: A group of bacteria known for their resistance to multiple antibiotics and their role in hospital-acquired infections in both humans and animals.
• These bacteria pose a concern particularly in veterinary hospitals where they can contaminate environmental surfaces, leading to infection risks.
• Controlling environmental contamination is critical for infection prevention, often involving chemical disinfectants;
• Steam cleaning offers a potential alternative method that uses high temperature rather than chemicals.

Objectives

• To evaluate whether steam cleaning effectively reduces the presence of ESKAPE bacteria and Escherichia coli on environmental surfaces in an equine hospital stable setting.
• To compare bacterial reductions on different surface types: smooth metallic doors versus rough rubber walls.
• To determine the utility of ATP bioluminescence swabs as quick cleanliness indicators compared to standard microbiological culture.
• To characterize antibiotic resistance genes in bacteria surviving steam cleaning.

Methods

• Sampling locations: Smooth metallic doors and rough rubber stable walls in the horse stables.
• Timepoints: Environmental samples were collected before and after steam cleaning.
• Microbiological analysis: Samples cultured specifically for ESKAPE organisms and Escherichia coli presence.
• ATP bioluminescence swabs: Taken alongside to quickly measure organic material indicative of contamination.
• Settle plates: Used to detect aerosolized bacteria to assess airborne contamination.
• Whole Genome Sequencing (WGS): Performed on selected isolates found after steam cleaning to identify antimicrobial resistance genes.

Results

• Reduction in ESKAPE organisms:
  • Significant reduction on smooth metallic doors (52% reduction).
  • Only a minor reduction on rough rubber walls (10% reduction).
  • Statistical significance was strong (p = 0.004), indicating that smoother surfaces are more amenable to effective steam cleaning.
• ATP bioluminescence findings:
  • ATP swabs provided a rapid cleanliness assessment but had no significant correlation with bacterial culture results (Spearman’s ρ=0.082, p=0.467).
  • This suggests ATP readings alone may not be reliable to indicate presence or absence of ESKAPE bacteria.
• Aerosol contamination:
  • No ESKAPE organisms were detected on settle plates before or after cleaning, indicating minimal airborne contamination under study conditions.
• Whole Genome Sequencing (WGS):
  • Seventeen ESKAPE isolates recovered after steam cleaning were sequenced.
  • All showed resistance genes to at least four antimicrobial classes, confirming their multidrug resistant nature.
  • Six isolates also carried “qacE” genes, which confer resistance to quaternary ammonium compounds, common chemical disinfectants.
  • This highlights the potential benefit of steam cleaning over chemical methods in managing resistant strains.

Conclusions

• Steam cleaning effectively reduces the contamination of multidrug-resistant ESKAPE organisms on smooth environmental surfaces such as metallic doors in equine hospital stables.
• The technology showed less efficacy on rough surfaces like rubber walls, indicating surface texture influences cleaning effectiveness.
• ATP bioluminescence alone is not a reliable indicator of multidrug-resistant bacteria presence.
• Steam cleaning may provide an environmentally friendly alternative method to chemical disinfectants, especially important where bacteria carry resistance to common disinfectant agents.
• The research supports integrating steam cleaning as part of infection control protocols in veterinary settings, particularly focusing on surface types for maximal effect.