An Improved Protocol for Indoor Airborne Bacterial Enumeration and Elimination Using a Cold- Plasma Air Sanitizer: A pilot study
DOI:
https://doi.org/10.54878/r2x84577Keywords:
Airborne-bacteria, Elemination, Bacterial-enumeration, Cold-Plamsa technology, Indoor-Air qualityAbstract
Airborne bacteria pose significant health risks in indoor environments, particularly for immunocompromised individuals. Air sanitizers represent a promising intervention for reducing microbial contamination in enclosed spaces. Objectives: This study evaluated the efficacy of a cold-plasma air sanitizer in reducing airborne bacterial contamination and developed a standardized protocol for bacterial enumeration in indoor air samples. Methods: Air samples (500 L per sample) were collected using a Sugold FX-100ST microbial air sampler (flow rate 100 L/min for 5 minutes) from microbiology and hematology teaching laboratories (1000 m³ room volume) at Gulf Medical University. Samples were collected immediately before sanitizer activation (baseline) and at 30-minute intervals during cold-plasma treatment (TPA Air Technology, Germany) for 24 hours. Samples were directly inoculated onto Chocolate agar, CLED agar, and Chromogenic UTI agar and incubated at 37°C for 24-48 hours. Total airborne particle counts (0.3-10 μm) were measured using an Atmotech particle counter. Experiments were performed in triplicate on three separate days (n=9 per time point). Bacterial identification was performed using Gram staining and biochemical tests. Statistical analysis employed paired t-tests and one-way ANOVA (p<0.05). Results: Significant bacterial reductions were observed following sanitizer activation. Baseline bacterial concentrations were 75.4±12.3 CFU/500L on Chocolate agar, 59.2±10.8 CFU/500L on CLED agar, and 26.4±6.7 CFU/500L on Chromogenic agar. Mean reduction rates at 24 hours were 94.7%, 96.5%, and 96.1%, respectively. Predominant organisms were Micrococcus spp. (62%) and Bacillus spp. (28%). Coagulase-positive Staphylococcus aureus (n=2) and Gram-negative species including Burkholderia cepacia and Stenotrophomonas maltophilia were also isolated. Strong positive correlation was observed between particle counts and bacterial concentrations (r=0.89, p<0.001). Conclusion: Cold-plasma air sanitization effectively reduced airborne bacteria by >90% within 24 hours. The standardized enumeration protocol developed in this study provides a simplified approach for indoor air quality assessment. Implementation of cold-plasma technology in healthcare settings could reduce respiratory infection risks for susceptible populations.
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