Characterization of Bacteroides Species Isolated From Soft Tissue Infections in Cats

Abstract

A total of 77 strains of Gram negative anaerobes belonging to the genus Bacteroides and isolated from 60 subcutaneous abscesses and 10 cases of pyothorax in cats, have been examined morphologically and biochemically. Colony pigmentation, gas chromatography and biochemical analysis placed them into two major categories‐those which produced pigmented colonies (Group 1) and those which failed to produce pigmented colonies after 14 d on laked blood agar (Group 2). All 29 strains in Group 1 produced acetic, propionic, isobutyric, butyric, isovaleric and succinic acids but failed to ferment carbohydrates, and were classified as B. asaccharolyticus. All organisms in Group 2 produced acetic, propionic, isobutyric, isovaleric and succinic acids and were divided into four categories based on indole production and bile tolerance. Designation to species was then decided on the basis of phenylacetic acid production and sugar fermentation tests. This sequence of analysis of results enabled confident speciation of some groups of these organisms despite some biochemical variation of the cat strains when compared to human type strains.