Effect of topical 0.5% povidone-iodine compared to 5% natamycin in fungal keratitis caused by Fusarium solani in a rabbit model: a pilot study.
OBJECTIVE
To evaluate the efficacy of topical administration of 0.5% povidone-iodine in experimental Fusarium solani keratitis in rabbits.


METHODS
Fungal keratitis caused by Fusarium solani was induced in the right eye of 24 New Zealand rabbits. The rabbits were randomly divided into 3 different treatment groups: Group I (povidone-iodine) - treated with topical 0.5% povidone-iodine; Group II (natamycin) - treated with topical 5% natamycin; and Group III (control) - treated with topical saline solution. In all groups the rabbits were treated for three days and then sacrificed. The corneas were excised, macerated and immersed in 10 mL BHI. Culture samples were plated daily on Sabouraud's agar for 7 days, and the number of colony-forming units (CFU) was counted. The rabbits were clinically evaluated during the treatment period.


RESULTS
The povidone-iodine and natamycin groups demonstrated better efficacy than the control group based on the number of rabbits with no colonies growing. However, there were no statistically significant differences between the three groups when the number of CFU was analyzed (p>0.05).


CONCLUSIONS
Our study demonstrates important methodological considerations in the use of in vivo animal models for the testing of antifungal agents. Using this sample size and methodology of counting CFU, topical 0.5% povidone-iodine demonstrated no benefit in the treatment of experimental Fusarium solani when compared with topical 5% natamycin.
Oliveira
Lauro Augusto de
LA
Universidade Federal de São Paulo - São Paulo (SP) - Brazil. laopadilha@terra.com.br
Takata
Thales Takeo
TT
Shiguematsu
Alvio Isao
AI
Melo Júnior
Luiz Alberto Soares
LA
Gompertz
Olga Fischman
OF
Sousa
Luciene Barbosa de
LB
Mannis
Mark J
MJ
D000818:Animals; D000935:Antifungal Agents / Q000008:administration & dosage*; D015169:Colony Count, Microbial; D004195:Disease Models, Animal; D005670:Fusarium / Q000254:growth & development; D007634:Keratitis / Q000139:chemically induced / Q000188:drug therapy* / Q000382:microbiology; D008297:Male; D010866:Natamycin / Q000008:administration & dosage*; D010865:Pilot Projects; D011206:Povidone-Iodine / Q000008:administration & dosage*; D011817:Rabbits; D011897:Random Allocation
D000935:Antifungal Agents; D011206:Povidone-Iodine; D010866:Natamycin