The antimicrobial effect of Octenidine-dihydrochloride coated polymer tracheotomy tubes on Staphylococcus aureus and Pseudomonas aeruginosa colonisation

Contamination with S. aureus: Before any reprocessing, OCT coated tracheotomy tubes were colonized with 103 cfu/ml and uncoated tracheotomy tubes with 105 cfu/ml (P = 0.045). After reprocessing, no differences in bacterial concentration between modified and conventional tubes were observed.Contamination with P. aeruginosa: Before reprocessing, OCT coated tubes were colonized with 106 cfu/ml and uncoated tubes with 107 cfu/ml (P = 0.006). After reprocessing, no significant differences were observed.OCT coating initially inhibits S. aureus and P. aeruginosa colonisation on tracheotomy tubes. This effect, however, vanishes quickly after reprocessing of the tubes due to poor adhesive properties of the antimicrobial compound. Despite the known antimicrobial effect of OCT, its use for antimicrobial coating of tracheotomy tubes is limited unless methods are developed to allow sustained attachment to the tube.In comprehensive studies examining the aetiology of ventilator-associated pneumonia (VAP), Staphylococcus (S.) aureus and Pseudomonas (P.) aeruginosa have been found to be the most frequently isolated gram positive and gram negative organisms, respectively [1]. Nosocomial pneumonia in intensive care units (ICU) caused by S. aureus has increased steadily over the past two decades [2]. After only a few days of mechanical ventilation, the cuffed polymer endotracheal tube is coated with a thick bacterial biofilm which has to be regarded as a continuous source of bacterial colonization of the lower respiratory tract ultimately resulting in VAP [3]. Treatment of infections associated with medical devices is often frustrated by the inability of antibiotics to penetrate biofilms and the increasing resistance of microbes to antibiotics [4]. In unpublished studies, we have identified bacterial colonization of 106 colony forming units (cfu)/ml on cuffed tracheotomy tubes after 3 days of use.Silver tracheotomy tubes with inherent antimicrobial properties previously used in patient