Differences in protein profiles betweenstrains obtained from healthy and infected dogs.

Abstract

causes infections of the skin and mucous membranes, especially in individuals with metabolic, hormonal, and immunological disorders. The search forproperties that differentiate isolates from healthy and infected animals may result in the identification of typically commensal and potentially pathogenic strains within the entire species. We aimed to determine and compare protein profiles ofstrains isolated from 30 dogs with clinical symptoms of otitis externa and 34 dogs without symptoms of any disease. Two-dimensional gel electrophoresis was applied, and proteins distinguishing the two groups of strains were identified by liquid chromatography coupled with tandem mass spectrometry. Significant differences were found between potentially pathogenic and commensal isolates. The most significant finding was the presence of nicotinamide adenine dinucleotide phosphate (NADP)-dependent mannitol dehydrogenase and ketol-acid reductoisomerase amongstrains obtained from dogs with otitis externa. Nevertheless, it is not clear whether they are associated directly with the pathogenicity or they play the role of fungal allergen. On the basis of these findings, we can conclude that there may be two distinct groups ofstrains-one typically commensal and the other with properties that enhance the infection process. These results may be used for more precise diagnosis and identification of potentially pathogenic strains in the future.