Comparison of fluoroquinolone kinetics of kill in susceptible and resistant Gram-positive conjunctival pathogens

Peter A. D’Arienzo1, Rudolph S. Wagner2, Tiffany Jamison3, Belinda Bell3, Joseph J. Dajcs3, David W. Stroman3
1Catholic Medical Center of Brooklyn and Queens, Brooklyn, USA
2New Jersey Medical School, Newark, USA
3Alcon Research Ltd., Fort Worth, USA

Tóm tắt

The purpose of this study was to compare moxifloxacin’s rate of kill of susceptible and resistant Gram-positive organisms with that of ciprofloxacin and ofloxacin, using concentrations found in human conjunctiva after instillation of one drop. Staphylococcus aureus (S. aureus) and Streptococcus pneumoniae (S. pneumoniae) isolates were exposed to moxifloxacin, ciprofloxacin, or ofloxacin diluted to human conjunctival concentrations achieved after instillation of one drop. These treated isolates were cultured on blood agar plates at 0, 15, 30, and 60 minutes after exposure, and incubated to observe the number of surviving colony-forming units/mL. In susceptible S. pneumoniae, moxifloxacin showed the most rapid reduction of colonies at 15 and 30 minutes, with the fewest colonies at 60 minutes compared with ciprofloxacin and ofloxacin. In S. pneumoniae resistant to ciprofloxacin and ofloxacin, moxifloxacin had rapid reduction in colonies at each time point and near-eradication at 60 minutes, while ciprofloxacin and ofloxacin had an increase in colonies at 60 minutes. In susceptible S. aureus, moxifloxacin had a rapid decrease in colonies at 15 and 30 minutes, compared with a slight reduction in colonies at these intervals for the other antibiotics. In methicillin-resistant S. aureus with cross-resistance to fluoroquinolones and other antibiotics, moxifloxacin had a decrease in colonies at each time point compared with an increase at each time point for ciprofloxacin and ofloxacin. Moxifloxacin showed an increased speed of kill against both of the common susceptible Gram-positive conjunctival pathogens, compared with the inconsistency of killing activity of two other fluoroquinolones tested. In addition, at the concentration level achieved in the conjunctiva after the instillation of one drop, moxifloxacin effectively and rapidly killed resistant Gram-positive conjunctival pathogens, while ciprofloxacin and ofloxacin had no effect against these organisms.

Từ khóa


Tài liệu tham khảo

Gigliotti F, Williams WT, Hayden FG, et al. Etiology of acute conjunctivitis in children. J Pediatr. 1981;98:531–536. Weiss A, Brinser JH, Nazar-Stewart V. Acute conjunctivitis in childhood. J Pediatr. 1993;122:10–14. Patel PB, Diaz MC, Bennett JE, Attia MW. Clinical features of bacterial conjunctivitis in children. Acad Emerg Med. 2007;14:1–5. Stroman DW, Cupp GA, Schlech BA. Resistance patterns in conjunctivitis and blepharitis in 2006. Invest Ophthalmol Vis Sci. 2007;48:2680. Soukiasian SH, Baum J. Bacterial conjunctivitis. In: Krachmer JH, Mannis MJ, Holland EJ, eds. Cornea. Version 2. St. Louis, MI: Elsevier-Mosby;2005:759–3172. Lichtenstein SJ, Wagner RS, Jamison T, Bell B, Stroman DW. Speed of bacterial kill with a fluoroquinolone compared with nonfluoroquinolones: clinical implications and a review of kinetics of kill studies. Adv Ther. 2007;24:1098–1111. Wagner RS, Granet DB, Lichetenstein SL, et al. Kinetics of kill of bacterial conjunctivitis isolates with moxifloxacin, a fluoroquinolone, compared with the aminoglycosides tobramycin and gentamicin. Clin Ophthalmol. 2010;4:41–45. Stroman DW, Dajcs JJ, Cupp GA, Schlech BA. In vitro and in vivo potency of moxifloxacin and moxifloxacin ophthalmic solution 0.5%, a new topical fluoroquinolone. Surv Ophthalmol. 2005;50(suppl. 1):S16–S31. Wagner RS, Abelson MB, Shapiro A, Torkildsen G. Evaluation of moxifloxacin, ciprofloxacin, gatifloxacin, ofloxacin, and levofloxacin concentrations in human conjunctival tissue. Arch Ophthalmol. 2005;123:1282–1283. Lichtenstein SJ, Dorfman M, Kennedy R, Stroman D. Controlling contagious bacterial conjunctivitis. J Pediatr Ophthalmol Strabismus. 2006;43:19–26.