Characterization of black‐pigmented Bacteroides strains isolated from animals

Abstract

The aims of the study were the isolation of strains of black-pigmented Bacteroides from the gingival sulcus of different animals, their biochemical and immunological characterization and comparison of their properties for classification within the genus. A total of 104 strains, isolated from cats, dogs, racoons and a Jaguar, were characterized on the basis of fermentation of carbohydrates, metabolic end products, hemagglutination studies, enzymatic activities, catalase production and indirect immunofluorescence. No differences were observed between the strains regardless of their animal origin. The strains did not ferment carbohydrates, produce phenylacetic acid, show an array of enzyme activities or agglutinate sheep red blood cells. They were catalase-positive and so differed from the human oral strains of B. gingivalis. Immunofluorescence microscopy revealed that the animal strains shared at least 1 major antigen with B. gingivalis but none with B. asaccharolyticus. Apart from their catalase activity, the animal strains isolated were similar to those of human B. gingivalis strains.