J. Baker1, E. Gulbins1,2, M. J. Edwards1, A. Seitz1 1University Of Cincinnati,Department Of Surgery,Cincinnati, OH, USA 2University Of Duisburg-Essen,Department Of Molecular Biology,Essen, , Germany
Introduction: Surgical site infections affect up to 5% of patients undergoing inpatient surgery with a cost of $10 billion annually. Pseudomonas aeruginosa (P. aeruginosa) is the most common gram-negative pathogen and accounts for approximately 9% of SSIs. Triclosan coated suture (VICRYL plus) was introduced by Ethicon and has demonstrated in vitro and in vivo inhibition of bacterial growth against multiple pathogens. We aimed to test our antibiotic coated suture versus VICRYL plus® suture against P. aeruginosa in vitro. We hypothesized that our suture would significantly decrease bacterial colonization compared to VICRYL plus®.
Methods: Single stranded 2-0 VICRYL suture was coated with various antibiotics (levofloxacin, chloramphenicol, doxycycline, erythromycin, and vehicle control) using a proprietary method. P. aeruginosa was incubated overnight on tryptic soy broth (TSB) agar plates. Sterile cotton tip applicators were used to transfer bacteria to TSB media and were incubated for 1 hour under agitation at 125 RPM into log growth phase. An inoculate of 1000 cfu in 1000 μL was prepared by measuring the optical density at 550 nm and calculating dilutions based upon a previously prepared standardization curve. Bacterial solution was placed in each well of a 24 well plate along with a 2 cm length of coated suture. The plate was then incubated at 37oC , at 100% humidity for 24 hours. The sutures were then removed and placed in 10 mL of PBS, sonicated in a 37oC water bath for 10 minutes to release adherent bacteria. Bacteria were then quantified by the plate dilution method.
Results: Doxycycline, chloramphenicol, and levofloxacin coated VICRYL significantly reduced P. aeruginosa colonization compared to vehicle coated VICRYL (99.97%, 99.06%, and 99.99%, respectively; p<0.05) and VICRYL plus® (99.95%, 98.50%, and 99.0%, respectively; p<0.05). There was no significant difference between vehicle coated VICRYL and VICRYL plus® (37.13%; p 0.11) against P. aeruginosa.
Conclusion: Our method of antibiotic coating significantly reduced P. aeruginosa colonization of VICRYL suture compared to both vehicle coated suture and VICRYL plus®. Our novel antibiotic coated suture is an effective tool to reduce bacterial colonization in vitro, and may prove better at preventing SSIs than commercially available VICRYL plus®.
