In vitro susceptibility patterns of Aspergillus and Fusarium species isolated from equine ulcerative keratomycosis cases in the midwestern and southern United States with inclusion of the new antifungal agent voriconazole.
OBJECTIVE
To evaluate and compare the in vitro susceptibility of Aspergillus and Fusarium spp. isolated from horses with ulcerative keratomycosis, address regional differences in equine keratomycosis isolates, and provide susceptibility data to update prior studies.


METHODS
Fourteen horses with ulcerative keratomycosis.


METHODS
Banked fungal isolates from equine corneal ulcers (eight Aspergillus spp. and six Fusarium spp.) were identified at The University of Texas Health Science Center at San Antonio. In vitro minimum inhibitory concentration and susceptibility to natamycin, fluconazole, itraconazole, voriconazole, ketoconazole, and miconazole were determined for each isolate.


RESULTS
Fungi were significantly more susceptible to voriconazole than to natamycin, itraconazole, fluconazole, and ketoconazole, but miconazole susceptibility did not differ significantly from voriconazole. Aspergillus spp. were most susceptible to voriconazole, miconazole, and itraconazole, which were significantly better to fluconazole and ketoconazole. Fusarium spp. susceptibility was greatest to natamycin and voriconazole and lowest to itraconazole and ketoconazole. Fusarium spp. were significantly less susceptible to itraconazole and ketoconazole compared to natamycin. No significant differences in susceptibility were found when isolates from Florida were compared with isolates from other states.


CONCLUSIONS
Based on in vitro evidence, voriconazole appears to be the most effective antifungal for initial treatment of equine keratomycosis in the midwestern and southern United States. Results are comparable with previous studies in that isolated fungi from equine keratomycosis cases showed consistently poor susceptibility to fluconazole. Organisms isolated in different geographic locations of the midwestern and southern United States appeared to have similar patterns of antifungal susceptibility.
Pearce
Jacqueline W
JW
Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri-Columbia, Columbia, MO 65211, USA. pearcej@missouri.edu
Giuliano
Elizabeth A
EA
Moore
Cecil P
CP
D000818:Animals; D000935:Antifungal Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001230:Aspergillus / Q000187:drug effects*; D003320:Corneal Ulcer / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*; D015821:Eye Infections, Fungal / Q000188:drug therapy / Q000662:veterinary*; D005670:Fusarium / Q000187:drug effects*; D006734:Horse Diseases / Q000188:drug therapy / Q000382:microbiology*; D006736:Horses; D008826:Microbial Sensitivity Tests; D011743:Pyrimidines / Q000494:pharmacology*; D014230:Triazoles / Q000494:pharmacology*; D065819:Voriconazole
D000935:Antifungal Agents; D011743:Pyrimidines; D014230:Triazoles; D065819:Voriconazole