Formation and Prevention of Biofilms on Airway Management Devices

Polymicrobial biofilm formation on airway management devices such as endotracheal and tracheostomy tubing is a significant risk factor for the onset of ventilator-associated pneumonia. The most common colonising microbes found within biofilms are reported to be similar for both endotracheal and tracheostomy tubing, with the most common bacteria including P. aeruginosa, Klebsiella spp., S. aureus and coagulase-negative Staphylococci, and the most common fungal pathogen being C. albicans. Characterisation of polymicrobial biofilms on tracheal tubing is generally limited to microbial culture-based analysis, and we postulate this may have underestimated the role that fungi play. We propose that the interplay between Candida species and co-colonising bacteria is critical to the development of biofilms that form on airway management devices. This review also argues for increased consideration of host factors and conditioning films in the characterisation of tracheal tube biofilms and the development of prevention strategies. Host factors such as mucin and bile found on tracheostomy tubing can significantly alter microbial behaviour, but we have much to learn as to their role in biofilm formation and maturation. Significant efforts have been made to determine the composition of polymicrobial biofilms; however, much remains to be determined if more effective management strategies are to reach the clinic and improve patient outcomes.