PURPOSE: The aim of this study was to determine whether a preservative (0.005% benzalkonium chloride [BAK]) enhances the antibacterial efficacy of an antibiotic (0.3% gatifloxacin, [GAT]) in vivo. METHODS: Rabbits were inoculated intrastromally with GAT-resistant, methicillin-resistant Staphylococcus aureus or Staphylococcus epidermidis and then divided into four treatment groups: 0.3% GAT + 0.005% BAK; 0.3% GAT without BAK; vehicle including 0.005% BAK; and saline control. At 4 h postinoculation, topical treatment was initiated in both eyes every 15 min for 5 h. One (1) h after therapy, corneal colony counts were determined. RESULTS: For S. aureus, duplicate experiments demonstrated that GAT + BAK and GAT without BAK significantly reduced colony counts, compared with BAK or saline (P < 0.05). Further, GAT + BAK significantly reduced colony counts, compared with GAT without BAK. BAK alone was equivalent to the saline control. For S. epidermidis, duplicate experiments demonstrated that GAT + BAK and GAT without BAK significantly reduced colony counts, compared with BAK or saline (P < 0.05). There were no differences between GAT + BAK and GAT without BAK for S. epidermidis. CONCLUSIONS: For the first time, we demonstrated that a preservative (0.005% BAK) significantly enhanced the antibacterial efficacy of an antibiotic (0.3% GAT) in an experimental rabbit model of intrastromal keratitis.
PURPOSE: The aim of this study was to determine whether a preservative (0.005% benzalkonium chloride [BAK]) enhances the antibacterial efficacy of an antibiotic (0.3% gatifloxacin, [GAT]) in vivo. METHODS:Rabbits were inoculated intrastromally with GAT-resistant, methicillin-resistant Staphylococcus aureus or Staphylococcus epidermidis and then divided into four treatment groups: 0.3% GAT + 0.005% BAK; 0.3% GAT without BAK; vehicle including 0.005% BAK; and saline control. At 4 h postinoculation, topical treatment was initiated in both eyes every 15 min for 5 h. One (1) h after therapy, corneal colony counts were determined. RESULTS: For S. aureus, duplicate experiments demonstrated that GAT + BAK and GAT without BAK significantly reduced colony counts, compared with BAK or saline (P < 0.05). Further, GAT + BAK significantly reduced colony counts, compared with GAT without BAK. BAK alone was equivalent to the saline control. For S. epidermidis, duplicate experiments demonstrated that GAT + BAK and GAT without BAK significantly reduced colony counts, compared with BAK or saline (P < 0.05). There were no differences between GAT + BAK and GAT without BAK for S. epidermidis. CONCLUSIONS: For the first time, we demonstrated that a preservative (0.005% BAK) significantly enhanced the antibacterial efficacy of an antibiotic (0.3% GAT) in an experimental rabbit model of intrastromal keratitis.
Authors: Regis P Kowalski; Eric G Romanowski; Francis S Mah; Robert M Q Shanks; Y J Gordon Journal: Acta Ophthalmol Date: 2010-04-23 Impact factor: 3.761
Authors: Eric G Romanowski; Tyler A Kowalski; Katherine E O'Connor; Kathleen A Yates; Francis S Mah; Robert M Q Shanks; Regis P Kowalski Journal: J Ocul Pharmacol Ther Date: 2015-11-06 Impact factor: 2.671
Authors: Randall Olson; Eric Donnenfeld; Frank A Bucci; Francis W Price; Michael Raizman; Kerry Solomon; Uday Devgan; William Trattler; Steven Dell; R Bruce Wallace; Michelle Callegan; Heather Brown; Peter J McDonnell; Taryn Conway; Rhett M Schiffman; David A Hollander Journal: Clin Ophthalmol Date: 2010-12-10