Comparative efficacy of besifloxacin and other fluoroquinolones in a prophylaxis model of penicillin-resistant Streptococcus pneumoniae rabbit endophthalmitis.
OBJECTIVE
To study the efficacy of topical administration of gatifloxacin (0.3%), moxifloxacin (0.5%) ophthalmic solutions, and besifloxacin (0.6%) ophthalmic suspension as prophylaxis and treatment of pneumococcal endophthalmitis.


METHODS
Four groups of New Zealand white rabbits were topically treated with gatifloxacin, moxifloxacin, besifloxacin, and phosphate-buffered saline (PBS) at the following time points: 60, 45, 30, and 15 min before infection, immediately after infection, and then 6, 12, 18, and 24 h postinfection. Penicillin-resistant Streptococcus pneumoniae (PRSP; 10(6) colony-forming unit [CFU] in 50 microL) was injected into the aqueous humor of each eye. The clinical severity of the eyes was assessed by 2 masked observers 24 h postinfection. Aqueous and vitreous samples were collected, diluted, and plated to determine recovered CFU.


RESULTS
Fluoroquinolone-treated eyes had significantly lower clinical scores and bacteria recovered from the aqueous humor than the PBS-treated eyes. There was no difference, however, among the fluoroquinolone-treated groups. In contrast, none of the fluoroquinolones reduced the number of bacteria recovered (CFU) from the vitreous humor.


CONCLUSIONS
Besifloxacin is as effective as moxifloxacin and gatifloxacin in a rabbit model for topical prophylaxis and treatment of PRSP-induced endophthalmitis.
Norcross
Erin W
EW
Department of Microbiology, University of Mississippi Medical Center, Jackson, Mississippi 39216, USA.
Sanders
Melissa E
ME
Moore
Quincy
Q
Sanfilippo
Christine M
CM
Hesje
Christine K
CK
Shafiee
Afshin
A
Marquart
Mary E
ME
D000287:Administration, Topical; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology; D001372:Aza Compounds / Q000008:administration & dosage / Q000494:pharmacology*; D001381:Azepines / Q000008:administration & dosage / Q000494:pharmacology*; D015169:Colony Count, Microbial; D004195:Disease Models, Animal; D009877:Endophthalmitis / Q000188:drug therapy / Q000382:microbiology / Q000517:prevention & control*; D024841:Fluoroquinolones / Q000008:administration & dosage / Q000494:pharmacology*; D000077734:Gatifloxacin; D000077266:Moxifloxacin; D009883:Ophthalmic Solutions; D010403:Penicillin Resistance; D011008:Pneumococcal Infections / Q000188:drug therapy / Q000382:microbiology / Q000517:prevention & control; D011804:Quinolines / Q000008:administration & dosage / Q000494:pharmacology*; D011817:Rabbits; D012720:Severity of Illness Index; D013296:Streptococcus pneumoniae / Q000187:drug effects / Q000302:isolation & purification; D013997:Time Factors
D000900:Anti-Bacterial Agents; D001372:Aza Compounds; D001381:Azepines; D024841:Fluoroquinolones; D009883:Ophthalmic Solutions; D011804:Quinolines; C522124:besifloxacin; D000077734:Gatifloxacin; D000077266:Moxifloxacin