Effectiveness of mupirocin and polymyxin B in experimental Staphylococcus aureus, Pseudomonas aeruginosa, and Serratia marcescens keratitis.
OBJECTIVE
The purpose of this study was to determine the effectiveness of mupirocin and polymyxin B, alone and in combination, in vitro and in vivo using rabbit models of, and keratitis.


METHODS
Rabbit eyes were intrastromally injected with 1,000 colony-forming units (CFUs) of or or 100 CFUs of Rabbits were then treated with 2.7 mg/mL mupirocin, 10,000 U/mL polymyxin B, a mupirocin:polymyxin B combination, or 0.3% ciprofloxacin. Vehicle and untreated controls were also included. Treatment schedules depended on the strain injected. The number of CFUs was determined for all eyes after treatment.


RESULTS
The mupirocin:polymyxin B combination was effective for all three genera both in vitro and in vivo. For keratitis, the mupirocin:polymyxin B combination was more effective than either drug alone and significantly reduced the log number of bacteria in the cornea by more than 3 logs compared with the vehicle or untreated controls (p <or= 0.0016). For, the mupirocin:polymyxin B combination treatment significantly reduced the number of CFUs per cornea relative to the individual drugs, vehicle, or untreated controls (p <or= 0.016). For, the mupirocin:polymyxin B combination therapy significantly reduced the number of bacteria in rabbit corneas relative to the individual drugs, vehicle, or untreated groups (p <or= 0.0001). Therapy with the mupirocin:polymyxin B combination was equivalent to ciprofloxacin therapy (p = 0.80).


CONCLUSIONS
The mupirocin:polymyxin B combination was effective in treating experimental, and keratitis.
Moreau
Judy M
JM
Department of Microbiology, Immunology, and Parasitology, LSU Health Sciences Center, New Orleans, LA 70112, USA.
Conerly
Lisa L
LL
Hume
Emma B H
EB
Dajcs
Joseph J
JJ
Girgis
Dalia O
DO
Cannon
Bennetta M
BM
Thibodeaux
Brett A
BA
Stroman
David W
DW
O'Callaghan
Richard J
RJ
D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D015169:Colony Count, Microbial; D003315:Cornea / Q000382:microbiology; D004195:Disease Models, Animal; D004359:Drug Therapy, Combination; D015818:Eye Infections, Bacterial / Q000188:drug therapy* / Q000382:microbiology; D007634:Keratitis / Q000188:drug therapy* / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D016712:Mupirocin / Q000008:administration & dosage / Q000627:therapeutic use*; D009883:Ophthalmic Solutions; D011112:Polymyxin B / Q000008:administration & dosage / Q000627:therapeutic use*; D011552:Pseudomonas Infections / Q000188:drug therapy* / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification; D011817:Rabbits; D016868:Serratia Infections / Q000188:drug therapy* / Q000382:microbiology; D012706:Serratia marcescens / Q000302:isolation & purification; D013203:Staphylococcal Infections / Q000188:drug therapy* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000302:isolation & purification; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents; D009883:Ophthalmic Solutions; D016712:Mupirocin; D011112:Polymyxin B