Methods: Antimicrobial gelatin-based wraps were formed containing no antibiotic, M (0.1%)/R (0.05%), MesNA (5%), and M (0.1%)/R (0.05%)/MeSNA (5%). One-cm diameter silicone disks cut from TEs were covered with wraps. The disks were incubated with 5x105 CFU/ml clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and multi-drug resistant Pseudomonas aeruginosa (MDR-PA) in broth containing physiologic concentrations of collagenase. The inoculum was replaced weekly with fresh inoculum for 2 weeks. Each week disks were harvested and adherent organisms enumerated.
Results: Control silicone disks and no-antibiotic gelatin-wrapped disks yielded about 5x104 cfu/disc of adherent bacteria for each challenge organism. Wraps containing M/R completely inhibited all challenge organisms from attaching to the silicone at 1 week (p<0.001), but breakthrough occurred at week 2 for MDR-PA (at a level of 5x103 CFU/mL). The 5% MeSNA wraps did not inhibit adherence of MRSA or MDR-PA, but M/R/MeSNA wraps completely inhibited attachment of both challenge organisms for 2 weeks (p<0.001). Incorporation of MeSNA visibly decreased the rate of enzymatic dissolution of the wraps.
Conclusion: Addition of MeSNA (the MeSNA/M/R combination) enhanced the durability of antimicrobial efficacy of the M/R antimicrobial wrap against MDR-PA in a physiologic in vitro model.
the University of Texas MD Anderson Cancer Center:
Inventor of the Caprylic Acid - Glycerol Trinitrate Combination Technology
licensed by Novel Anti-Infective Technologies, LLC in which UTMDACC, Dr. Raad and Dr. Rosenblatt are shareholders.
Licensing agreement or royalty
G. M. Viola, None
J. Selber, None
I. Raad, Merck: Grant Investigator , Grant recipient
Pfizer: Speaker's Bureau , Speaker honorarium
Allergan: Grant Investigator , Grant recipient