Prevention of biofilm formation by polyquaternary polymer

ObjectiveBiofilm formation has been linked to device-associated infections in otolaryngology. This study was conducted to determine if a microbicidal polyquaternary polymer, poly diallyl-dimethylammonium chloride (pDADMAC) could prevent biofilm development by pathogens that commonly cause implant infections, Staphylococcus aureus and Pseudomonas aeruginosa.Methods and materialsThis study was prospective and controlled in vitro microbiological study. Polyurethane tubes (20 per treatment) with and without a polyquaternary polymer coating were briefly exposed to plasma or saline, then to S. aureus or P. aeruginosa. Polyurethane tubes were incubated in growth media. After 4 days, antibiotics were added to kill planktonic bacteria. S. aureus or P. aeruginosa bacterial counts and scanning electron microscopy (SEM) were performed.ResultsS. aureus biofilm counts were reduced by 8 logs on tubes with polyquaternary polymer coating compared to the control tubes, either with plasma (3.67E+01 ± 7.30E+01 vs 1.08E+09 ± 4.81E+08; P < 0.0001) or without plasma (3.70E+00 ± 1.10E+01 vs 6.50E+08 ± 2.79E+08; P < 0.0001). P. aeruginosa biofilm formation was also reduced on tubes with polyquaternary polymer, either with plasma (2.90E+07 ± 1.71E+07 vs 9.16E+08 ± 4.43E+08; P < 0.0001) or without plasma (2.50E+07 ± 9.54E+06 vs 3.35E+08 ± 2.18E+08; P < 0.001), but the reduction was only 1 log. On control tubes, plasma promoted S. aureus (1.08E+09 ± 4.81E+08 vs 6.05E+08 ± 2.79E+08; P < 0.0001) and P. aeruginosa (9.16E+08 ± 4.43E+08 vs 3.35E+08 ± 2.18E+08; P < 0.0001) bacterial counts but not on the tubes coated with polyquaternary polymer.ConclusionsIncorporation of the microbicidal polyquaternary polymer, pDADMAC, into polyurethane dramatically inhibits S. aureus biofilm formation. Further research is warranted to evaluate the efficacy and safety of this technology in otolaryngologic implants.