Assessment of air infectious contamination during wound care in a burn intensive care unit using shotgun metagenomics.

Background: Airborne microbial contamination in burn intensive care units (BICUs) poses a significant risk to immunocompromised patients. Wound care procedures, including dressing removal, may contribute to the aerosolization of pathogens and antimicrobial resistance genes. This study employs clinical metagenomics to analyze the microbial composition of air during wound care in a BICU.

Methods: Air and skin samples were collected over 3 days from a BICU patient with extensive burns (70% total body surface area). Air sampling was performed using 3 high-efficiency aerosol samplers. Microbial analysis included multiplex PCR for respiratory and herpes viruses, bacterial and fungal cultures, and metagenomic sequencing for taxonomic and resistome profiling.

Results: HSV-1 DNA was detected in air samples on days when dressing removal occurred, with the highest viral loads observed during intensive wound care. Bacterial diversity and antibiotic resistance gene prevalence were also highest on these days, with Enterobacterales and Micrococcales dominating the bacterial profile. Candida albicans was detected in skin cultures but not in air samples, likely due to its reduced airborne persistence.

Conclusions: This study demonstrates the significant impact of wound care on airborne microbial contamination in BICUs. Clinical metagenomics provides an advanced culture-independent approach to assess aerobiological risks, supporting improved infection control strategies in health care settings.