Comparative efficacy of topical gatifloxacin with ciprofloxacin, amikacin, and clarithromycin in the treatment of experimental Mycobacterium chelonae keratitis.
OBJECTIVE
To determine the comparative efficacy of topical gatifloxacin with ciprofloxacin, fortified amikacin, and clarithromycin against Mycobacterium chelonae keratitis in an animal model.


METHODS
Experimental M chelonae keratitis was induced via intrastromal inoculation in a rabbit model. Thirty-five rabbits were randomly divided into 5 groups and each group was treated hourly for 12 hours with topical 0.9% balanced salt solution, 0.3% gatifloxacin, 0.3% ciprofloxacin hydrochloride, a combination of topical fortified amikacin sulfate (50 mg/mL) and clarithromycin (10 mg/mL), or a triple combination of topical 0.3% gatifloxacin, fortified amikacin sulfate (50 mg/mL), and clarithromycin (10 mg/mL). Antibacterial efficacy of each regimen was determined by quantitative bacteriologic analysis.


RESULTS
Treatment with 0.3% gatifloxacin or the triple combination of 0.3% gatifloxacin, topical fortified amikacin sulfate (50 mg/mL), and clarithromycin (10 mg/mL) reduced the number of mycobacterial organisms more significantly than the controls that were treated with a topical balanced salt solution (both P<.001). Therapy with 0.3% gatifloxacin was more effective than 0.3% ciprofloxacin alone (P<.001) and demonstrated synergy by enhancing the efficacy of the combination of fortified amikacin (50 mg/mL) and clarithromycin (10 mg/mL) (P<.001). Neither 0.3% ciprofloxacin nor the combination of fortified amikacin (50 mg/mL) and clarithromycin (10 mg/mL) demonstrated a significant difference in activity against mycobacteria compared with the topical balanced salt solution.


CONCLUSIONS
These results suggest that topical 0.3% gatifloxacin ophthalmic solution can be a new initial treatment agent against M chelonae keratitis.Clinical Relevance Topical gatifloxacin 0.3% may provide an initial alternative in therapy of M chelonae keratitis.
Hyon
Joon-Young
JY
Ocular Microbiology and Immunology Laboratory, Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD 21287-9121, USA.
Joo
Myung-Jin
MJ
Hose
Stacey
S
Sinha
Debasish
D
Dick
James D
JD
O'Brien
Terrence P
TP
D000287:Administration, Topical; D000583:Amikacin / Q000008:administration & dosage / Q000627:therapeutic use; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D002939:Ciprofloxacin / Q000008:administration & dosage / Q000627:therapeutic use; D017291:Clarithromycin / Q000008:administration & dosage / Q000627:therapeutic use; D003315:Cornea / Q000382:microbiology; D003320:Corneal Ulcer / Q000188:drug therapy* / Q000382:microbiology; D004195:Disease Models, Animal; D004359:Drug Therapy, Combination; D015818:Eye Infections, Bacterial / Q000188:drug therapy* / Q000382:microbiology; D024841:Fluoroquinolones / Q000008:administration & dosage / Q000627:therapeutic use; D000077734:Gatifloxacin; D008297:Male; D009165:Mycobacterium Infections, Nontuberculous / Q000188:drug therapy* / Q000382:microbiology; D016926:Mycobacterium chelonae / Q000302:isolation & purification*; D009883:Ophthalmic Solutions / Q000008:administration & dosage / Q000627:therapeutic use; D011817:Rabbits
D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D009883:Ophthalmic Solutions; D002939:Ciprofloxacin; D000583:Amikacin; D017291:Clarithromycin; D000077734:Gatifloxacin