Comparative Efficacy of Vancomycin Ointment versus Topical Moxifloxacin in the Treatment of MRSA Keratitis in Rabbits

Abstract

 

Purpose:

 

To evaluate the in vivo efficacy of vancomycin ointments (VCM,1% and 3%) versus topical moxifloxacin 0.5% in the treatmentof methicillin-resistant Staphylococcus aureus (MRSA) keratitisin rabbits.

 

Methods:

 

Experimental bacterial keratitis was induced in rabbits by cornealintrastromal injection of MRSA (2.5~5 10⁴ CFU/cornea). Two MRSAstrains (clinical isolates), SA08 and UA1 were used. VCM ointments(1%, 3%) and moxifloxacin were given from 24 hr postinfection,and were applied four times per day. Those eyes were enucleatedat 48 hr, 72 hr and 96 hr postinfection. Corneal homogenateswere plated with serial dilutions for quantitative bacteriology.

 

Results:

 

Tables showed the bacterial populations in cornea (log₁₀ CFU/ml).Both VCM ointments (1%, 3%) and moxifloxacin performed significantlybetter than control in the treatment of MRSA keratitis (P<0.01,respectively). VCM ointments (1%, 3%) performed significantlybetter than moxifloxacin in bactericidal activity for SA08 infection(P<0.01). However, in bactericidal activity for UA1 infection,there were no significant differences between these 2 drugs.

 

Conclusions:

 

VCM ointments (1%, 3%) and topical moxifloxacin 0.5% have similarefficacy in the treatment of MRSA keratitis in rabbits. Theseresults suggest a potential value for VCM ointment as an agentin the treatment of MRSA keratitis. 

 

 

Keywords: keratitis • antibiotics/antifungals/antiparasitics