Chemical and Phenotypic Characteristics of Flavobacterium thalpophilum Compared with Those of Other Flavobacterium and Sphingobacterium Species

Seven strains of Flavobacterium thalpophilum which were isolated from clinical sources were compared with the type strains of Sphingobacterium mizutae and seven species of Flavobacterium. These 15 strains were examined for 11 biochemical characteristics; minor phenotypic variations were observed for the 7 strains of F. thalpophilum. All 15 strains were characterized by four major cellular fatty acids (13-methyltetradecanoate, 2-hydroxy-13-methyltetradecanoate, 3-hydroxy-15-methylhexadecanoate, and a monounsaturated 16-carbon straight-chain acid). Sphingophospholipid long-chain bases were detected in all strains of F. thalpophilum but were not detected in Flavobacterium balustinum, Flavobacterium breve, Flavobacterium indologenes, Flavobacterium meningosepticum, or Flavobacterium odoratum. F. thalpophilum, Flavobacterium multivorum, Flavobacterium spiritivorum, and S. mizuate contained major amounts of menaquinone 7 but no menaquinone 6, whereas F. balustinum, F. breve, F. indologenes, F. meningosepticum, and F. odoratum contained major amounts of menaquinone 6 but no menaquinone 7. The phenotypic and chemical characteristics of F. thalpophilum indicate a close taxonomic relationship with F. multivorum, F. spiritivorum, and S. mizutae.