Quantitative comparison of fluoroquinolone therapies of experimental gram-negative bacterial keratitis.
OBJECTIVE
To determine the effectiveness of topically applied fluoroquinolones for experimental Pseudomonas or Serratia keratitis.


METHODS
Bacteria were injected intrastromally (10(3) colony forming units [CFU]). From 16 to 22 hours post-infection (PI), a single topical drop of moxifloxacin (Vigamox, 0.545%), levofloxacin (Quixin, 0.5%), ofloxacin (Ocuflox, 0.3%) or ciprofloxacin (Ciloxan, 0.3%) was applied every 30 minutes. At 23 hours PI, corneas were cultured quantitatively.


RESULTS
For Pseudomonas keratitis, untreated eyes contained 7 log CFU/cornea and antibiotic-treated eyes demonstrated a > or = 5-log reduction in CFU/cornea (p < or = 0.0001). Moxifloxacin, levofloxacin, or ciprofloxacin therapies were not significantly different from each other (p > or = 0.67). For Serratia keratitis, untreated eyes contained 7 logCFU/cornea whereas treated eyes had a > or = 2-log reduction (p < or = 0.0001). Moxifloxacin therapy proved most effective (p < or = 0.001).


CONCLUSIONS
Overall, moxifloxacin was the most effective of the four fluoroquinolones in reducing CFU/cornea in the rabbit model of gram-negative keratitis.
Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA.
Brett A
BA
Thibodeaux
Joseph J
JJ
Dajcs
Armando R
AR
Caballero
Mary E
ME
Marquart
Dalia O
DO
Girgis
Richard J
RJ
O'Callaghan
D000818:Animals; D000890:Anti-Infective Agents / Q000627:therapeutic use*; D001372:Aza Compounds / Q000627:therapeutic use; D002939:Ciprofloxacin / Q000627:therapeutic use; D015169:Colony Count, Microbial; D003315:Cornea / Q000382:microbiology; D015818:Eye Infections, Bacterial / Q000188:drug therapy* / Q000382:microbiology; D024841:Fluoroquinolones / Q000627:therapeutic use*; D007634:Keratitis / Q000188:drug therapy* / Q000382:microbiology; D064704:Levofloxacin; D008826:Microbial Sensitivity Tests; D000077266:Moxifloxacin; D015242:Ofloxacin / Q000627:therapeutic use; D011552:Pseudomonas Infections / Q000188:drug therapy* / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification; D011804:Quinolines / Q000627:therapeutic use; D011817:Rabbits; D016868:Serratia Infections / Q000188:drug therapy* / Q000382:microbiology; D012706:Serratia marcescens / Q000302:isolation & purification
D000890:Anti-Infective Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D011804:Quinolines; D002939:Ciprofloxacin; D064704:Levofloxacin; D015242:Ofloxacin; D000077266:Moxifloxacin