Fluoroquinolone therapy in Mycobacterium chelonae keratitis after lamellar keratectomy.
OBJECTIVE
To characterize a rabbit model of Mycobacterium chelonae keratitis after lamellar keratectomy and assess the effectiveness of fluoroquinolone therapy.


METHODS
University Laboratory, University of California, Irvine, California, USA.


METHODS
Twenty-eight New Zealand white rabbits had unilateral lamellar keratectomy with placement of 2.5 x 10(5) colony-forming units of log-phase M chelonae under each flap. Eyes (7 per group) were randomized and treated with sterile balanced salt solution, gatifloxacin 0.3%, ciprofloxacin 0.3%, or levofloxacin 0.5% 4 times daily. Two masked observers examined all eyes on days 2, 5, and 7 and weekly for 4 weeks. Severity of disease and bacterial culture results were the main outcomes measured. The means and standard deviations were calculated, and differences between the groups were statistically analyzed.


RESULTS
All eyes developed clinical disease. At the time the rabbits were killed, eyes treated with balanced salt solution, ciprofloxacin, levofloxacin, and gatifloxacin were culture positive in 6 (85.7%), 7 (100%), 6 (85.7%), and 3 (42.9%) of 7 eyes per group, respectively. Frequency of positive culture and the severity of clinical disease in gatifloxacin-treated eyes were significantly less (P < .05) than in the other groups combined.


CONCLUSIONS
The rabbit model of M chelonae keratitis was successfully developed in our study. A fourth-generation quinolone (gatifloxacin) showed the best performance among the fluoroquinolones tested in our experimental approach. The fourth-generation fluoroquinolone, gatifloxacin, could be effectively used for the treatment of mycobacterial keratitis.
Sarayba
Melvin A
MA
Department of Ophthalmology, University of California, Irvine, California, USA.
Shamie
Neda
N
Reiser
B J
BJ
Sweet
Paula M
PM
Taban
Mehran
M
Graff
Jordan M
JM
Kesler-Diaz
Anna
A
Osann
Kathryn E
KE
McDonnell
Peter J
PJ
D000818:Animals; D000890:Anti-Infective Agents / Q000627:therapeutic use*; D002939:Ciprofloxacin / Q000627:therapeutic use; D015169:Colony Count, Microbial; D003315:Cornea / Q000382:microbiology; D016039:Corneal Transplantation; D004195:Disease Models, Animal; D015818:Eye Infections, Bacterial / Q000188:drug therapy* / Q000382:microbiology; D024841:Fluoroquinolones / Q000627:therapeutic use*; D000077734:Gatifloxacin; D007634:Keratitis / Q000188:drug therapy* / Q000382:microbiology; D064704:Levofloxacin; D009165:Mycobacterium Infections, Nontuberculous / Q000188:drug therapy* / Q000382:microbiology; D016926:Mycobacterium chelonae / Q000502:physiology*; D015242:Ofloxacin / Q000627:therapeutic use; D011817:Rabbits
D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D002939:Ciprofloxacin; D064704:Levofloxacin; D015242:Ofloxacin; D000077734:Gatifloxacin