Detection, identification, and comparison of Capnocytophaga, Bacteroides ochraceus, and DF-1

Abstract

Working independently, 3 laboratories had recognized considerable similarity among certain strains of dysgonic, fermentative, capnophilic, surface translocating, gram-negative bacilli referred to as Capnocytophaga, B. ochraceus and Center for Disease Control biogroup DF-1. To determine the relationship among these groups, 21 strains were exchanged and independently characterized by the 3 laboratories. Additionally, a 4th laboratory examined the DNA homologies of the same strains. Using methods common to dental microbiology, 8 of the strains were isolated from the gingival sulcus and periodontal lesions and identified as Capnocytophaga. Three strains isolated from blood and transtracheal aspirate were characterized by conventional anaerobic methods and recorded as B. ochraceus. Ten strains isolated from sputum, blood, throat, spinal fuid and tracheal aspirate were identified as DF-1 with the methods of E. O. King and a buffered single-substrate technique. All strains were similar in respect to colonial and microscopic morphology, surface translocation, biochemical features, gas-liquid chromatograms of metabolic end products and DNA composition. These biogroups should be termed Capnocytophaga spp.