Potential role of Alternaria and Cladosporium species in canine lymphoplasmacytic rhinitis.

Abstract

OBJECTIVES: To evaluate the possible role of Alternaria and Cladosporium species in the pathogenesis of canine lymphoplasmacytic rhinitis by comparing the amount of specific fungal DNA in nasal mucosal biopsies between dogs without nasal neoplasia and those with lymphoplasmacytic rhinitis or nasal neoplasia. METHODS: Quantitative real-time polymerase chain reaction (qPCR) assays detecting DNA from Alternaria and Cladosporium fungi were applied to nasal mucosal biopsies collected from dogs with lymphoplasmacytic rhinitis (n&#x2009;=&#x2009;8), dogs with nasal neoplasia (n&#x2009;=&#x2009;10) and control animals (n&#x2009;=&#x2009;10). A copy number for each sample was calculated using a standard curve of known copy number and differences amongst groups were assessed using Kruskal-Wallis tests. RESULTS: No significant difference was found between the groups. Low levels of Alternaria DNA (10-100 copies/PCR) were detected in one sample; very low levels of DNA (<10 copies/qPCR) were detected in 6 samples, and 21 samples were negative. Low levels of Cladosporium DNA were detected in 2 samples; very low levels of DNA in 18; and 8 were negative. CLINICAL SIGNIFICANCE: Results of this study reveal that Alternaria and Cladosporium species are part of the canine nasal flora, and that these fungi are probably not involved in the pathogenesis of lymphoplasmacytic rhinitis.