Integral risk assessment associated to aerobiome dynamics and environmental parameters during septic surgical...

Surgical site infections (SSIs) are a major public health concern due to their impact on morbidity, mortality, healthcare costs, and prolonged hospital stays. Although prevention strategies have mainly focused on antibiotic prophylaxis, skin antisepsis, and surgical technique, airborne microbiological contamination in operating rooms has been poorly investigated.

To evaluate the environmental and microbiological dynamics associated with septic surgical procedures and their potential implications for infection control and occupational exposure.

Microbiological and environmental parameters were evaluated in 20 septic surgical procedures. Air quality and airborne bacterial and fungal loads were measured before, during, and after each procedure. Bacteria were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF), and fungi were identified by conventional mycology. A Vester matrix was used to prioritize 24 environmental, microbiological, and operational variables.

The intraoperative phase showed increased temperature, all particulate matter fractions (notably PM0.5), and Gram-positive bacterial bioburden. Fungal diversity increased and persisted postoperatively. MALDI-TOF identified clinically relevant taxa, including Staphylococcus aureus and Pseudomonas aeruginosa. The Vester matrix identified seven risk-generating scenarios, highlighting environmental conditions associated with increased microbiological burden. Key active variables included increased microbial bioburden, door openings, transient temperature elevation, and the humidity-fungal persistence interaction.

Septic surgical procedures induce environmental and microbiological changes in the operating room, increasing microbiological burden and conditions associated with microbial exposure, with potential implications for infection prevention and occupational health.