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 Efeito tópico de iodo-povidona 0,5% comparado com natamicina 5% em ceratites fúngicas causadas por Fusarium solani em um modelo animal de coelhos: estudo piloto

Content Partner: Directory of Open Access Journals. PURPOSE: 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.OBJETIVO: Avaliar a eficácia do uso tópico de iodo-povidona 0,5% em ceratite experimental por Fusarium solani em coelhos. MÉTODOS: Ceratite fúngica por Fusarium solani foi induzida no olho direito de 24 coelhos da raça New Zealand. Os coelhos foram divididos aleatoriamente em 3 diferentes grupos de tratamento: Grupo I (iodo-povidona) - tratados com iodo-povidona 0,5%; Grupo II (natamicina) - tratados com natamicina 5%; Grupo III (controle) - tratados com solução salina. Os coelhos dos 3 grupos foram tratados por 3 dias e sacrificados em seguida. As córneas foram removidas cirurgicamente, maceradas e incubadas em meio BHI. Semeou-se culturas em placas de ágar Sabouraud, diariamente, durante 7 dias, e contou-se o número de unidades formadoras de colônias (UFC). Os coelhos foram avaliados clinicamente durante o período de tratamento. RESULTADOS: Os grupos iodo-povidona e natamicina demonstraram melhor eficácia do que o grupo controle considerando-se o número de