International Journal of Advanced Veterinary Science and Technology, Volume 5 (Year 2016)

Molecular Characterization of Corynebacterium bovis causing Clinical Mastitis and Increasing Somatic-Cell Count

Langoni H., GuimarĂ£es F.F., Salina A., Ribeiro M. G., Baio P.V.P., Ramos J.N., Mota H.F., Vieira V.V., Mattos-Guaraldi A.L.

Abstract


Bovine mastitis remains the most economically important disease affecting dairy cows. Bacteria of the genus Corynebacterium spp., especially Corynebacterium bovis (C. bovis), are frequently isolated from bovine mastitis although there are divergent reports about the role of this pathogen in bovine mastitis. In the present study we report the presence of new C. bovis strains from milk exhibiting increased SCC of 12 cows with subclinical and clinical mastitis. Irregular Gram-positive bacilli isolated in pure cultures underwent conventional biochemical tests which generated indefinite phenotypic profiles (Corynebacterium mastitidis/C. bovis). API-Coryne System 3.0 identified all the milk isolates as C. bovis (code number 4501014; 99.9% confidence level). Phylogenetic analysis based on 16S rRNA and rpoB sequences confirmed the identification of the strains as C. bovis.