Airborne bacterial profiling and air disinfection efficacy in small animal hospitals in South Korea

초록

Importance: Airborne bacteria contribute to environmental hygiene challenges and may increase infection risk in veterinary hospitals. Objective: To evaluate the efficacy of a high-pressure spray system using neutral electrolyzed water (NEW) to reduce airborne bacterial concentrations in veterinary hospitals and to characterize clinically relevant airborne pathogens and antimicrobial resistance. Methods: Active air sampling was performed before and after disinfection in multiple room types across five small animal hospitals in South Korea. TAB concentrations were quantified as colony-forming units per cubic meter. Representative colonies were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, with confirmatory sequencing for selected isolates. Susceptibility testing was performed for Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp. using disk diffusion. Results: Pre-disinfection TAB levels averaged 358.2 CFU/m(3) across hospitals (range, 175.0-745.8 CFU/m(3)). Post-disinfection levels decreased to 150.6 CFU/m(3) (range, 65.7-406.7 CFU/m(3)), representing a 58% reduction (p < 0.05). Waiting rooms had the highest pre-disinfection levels (319.1 CFU/m(3)), and operating rooms the lowest (154.7 CFU/m(3)). Among 848 bacterial isolates, Micrococcus luteus, Staphylococcus spp., and Bacillus spp. were most frequent. Eight isolates (0.9%) were clinically important pathogens; two met multidrug resistance criteria. No targeted pathogens were detected after disinfection. Conclusions and Relevance: High-pressure neutral electrolyzed water spraying significantly reduced airborne bacterial loads in veterinary clinical environments, supporting routine air disinfection and microbial surveillance as components of infection prevention programs.

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