Eubacterium fossor sp. nov., an Agar-Corroding Organism from Normal Pharynx and Oral and Respiratory Tract Lesions of Horses

Abstract

A new species of Eubacterium, Eubacterium fossor, which was isolated from the pharynxes of normal horses and as a component of mixed flora from pyogenic diseases in horses, is described. This organism was found in oropharyngeal samples from seven normal horses, accounting for 22% of the anaerobic isolates, and was also isolated from pyogenic conditions (pleuropneumonia in two cases and parapharyngeal or tooth root abscesses in three cases) of horses. All strains were anaerobic, gram-positive rods which formed colonies that corroded agar. Noncorroding variants were not found. The addition of serum (5%, vol/vol) or Tween 80 (0.75%, vol/vol) was required to ensure optimum growth, which occurred in nutrient broth cultures (brain heart infusion or peptone-yeast extract medium). The fermentation products included major amounts of acetic and lactic acids. Strains of E. fossor sp. nov. had deoxyribonucleic acid guanine-plus-cytosine contents of 43 to 46 mol%. The type strain is strain NCTC 11919 (= Veterinary Pathology and Bacteriology Collection strain VPB 2127).