Nona-D-arginine amide for prophylaxis and treatment of experimental Pseudomonas aeruginosa keratitis.
OBJECTIVE
Nona-D-arginine amide (D9R) affected a cure of Pseudomonas aeruginosa corneal disease when combined with ciprofloxacin. In this study, we show that D9R alone and prophylactic treatment with D9R significantly reduced corneal pathology and bacterial burden associated with P. aeruginosa infection.


METHODS
Right eyes of Swiss Black mice received a 5 microl drop of either phosphate buffered saline (PBS, pH 7.4) or100 microM D9R every half-hour or hourly for 5 hr (total of 6-12 drops/eye) immediately after corneal wounding and subsequent infection with 1 x 10(6) colony forming units (CFU) of a cytotoxic strain of P. aeruginosa (ATCC 19660). For prophylactic treatment, eyes were treated hourly for 5 hr (total of 6 drops/eye) before infection with an invasive strain of P. aeruginosa (PAO1). At 24 hr post infection, all eyes were evaluated for pathology and scored on a scale of 0 (normal eye) to +4 (corneal perforation). Mice were then sacrificed and eyes were harvested for CFU determination (N = 15) or histopathology (N = 5).


RESULTS
P. aeruginosa-infected eyes treated with prophylactic D9R or with D9R after infection had significantly less ocular pathology (P < or = 0.001) and bacterial burden (P < or = 0.01) than eyes treated with PBS.


CONCLUSIONS
D9R (100 microM) would be a beneficial addition to current antimicrobial therapy for P. aeruginosa corneal disease. Furthermore, D9R can be incorporated into ophthalmic solutions as a prophylactic agent with the potential of reducing the incidence and severity of P. aeruginosa ocular infection.
Karicherla
Priyanka
P
Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, USA.
Hobden
Jeffery A
JA
D000818:Animals; D019072:Antibiotic Prophylaxis; D015169:Colony Count, Microbial; D003315:Cornea / Q000382:microbiology; D003320:Corneal Ulcer / Q000188:drug therapy* / Q000382:microbiology; D004195:Disease Models, Animal; D018450:Disease Progression; D015818:Eye Infections, Bacterial / Q000188:drug therapy* / Q000382:microbiology; D005260:Female; D045683:Furin / Q000037:antagonists & inhibitors; D008297:Male; D051379:Mice; D009842:Oligopeptides / Q000627:therapeutic use*; D011552:Pseudomonas Infections / Q000188:drug therapy* / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification
D009842:Oligopeptides; C491427:nonaarginine; C555621:nonaarginine amide; D045683:Furin