Effectiveness of ciprofloxacin, levofloxacin, or moxifloxacin for treatment of experimental Staphylococcus aureus keratitis.
The purpose of this study was to quantitatively compare, in a rabbit keratitis model, the levels of effectiveness of moxifloxacin, levofloxacin, and ciprofloxacin for the treatment of Staphylococcus aureus isolates of diverse antibiotic susceptibilities. Rabbit eyes were intrastromally injected with approximately 100 CFU of methicillin-sensitive or methicillin-resistant S. aureus (MSSA or MRSA, respectively) organisms that were either sensitive or resistant to ofloxacin. One drop of moxifloxacin (0.5%), levofloxacin (0.5%), or ciprofloxacin (0.3%) was topically applied hourly from 4 to 9 (early) or 10 to 15 (late) h postinfection. At 1 h after cessation of therapy, the corneas were harvested, and the number of CFU per cornea was determined. For the ofloxacin-sensitive strains, early treatment of MSSA or MRSA with moxifloxacin, levofloxacin, or ciprofloxacin produced approximately a 5-log decrease in CFU per cornea relative to that in untreated eyes (P </= 0.0001). For late therapy of ofloxacin-sensitive strains, moxifloxacin, levofloxacin, and ciprofloxacin produced approximately 5-, 4-, and 2- to 3-log reductions in CFU per cornea, respectively (P </= 0.0001). Early treatment of the ofloxacin-resistant strains with either moxifloxacin or levofloxacin produced a >/=4-log or >/=3-log decrease, respectively, in the MSSA or MRSA strains (P </= 0.0001), whereas ciprofloxacin treatment produced a 1-log decrease in CFU per cornea relative to that in untreated eyes (P = 0.1540). For late treatment of ofloxacin-resistant strains, levofloxacin and ciprofloxacin failed to significantly reduce the number of CFU per cornea (P >/= 0.3627), whereas moxifloxacin produced a significant reduction in CFU per cornea of approximately 1 log (P </= 0.0194). Therefore, for three of the four treatments tested, moxifloxacin demonstrated greater effectiveness than either levofloxacin or ciprofloxacin.
Dajcs
Joseph J
JJ
Department of Microbiology, Immunology, and Parasitology, LSU Health Sciences Center, 1901 Perdido St., New Orleans, LA 70112, USA.
Thibodeaux
Brett A
BA
Marquart
Mary E
ME
Girgis
Dalia O
DO
Traidej
Mullika
M
O'Callaghan
Richard J
RJ
D000818:Animals; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001372:Aza Compounds / Q000008:administration & dosage / Q000627:therapeutic use*; D002939:Ciprofloxacin / Q000008:administration & dosage / Q000627:therapeutic use*; D003315:Cornea / Q000382:microbiology; D024881:Drug Resistance, Bacterial; D024841:Fluoroquinolones; D007634:Keratitis / Q000188:drug therapy* / Q000382:microbiology; D064704:Levofloxacin; D000077266:Moxifloxacin; D015242:Ofloxacin / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D011804:Quinolines / Q000008:administration & dosage / Q000627:therapeutic use*; D011817:Rabbits; D013203:Staphylococcal Infections / Q000188:drug therapy* / Q000382:microbiology
D000890:Anti-Infective Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D011804:Quinolines; D002939:Ciprofloxacin; D064704:Levofloxacin; D015242:Ofloxacin; D000077266:Moxifloxacin