Leptotrichia buccalis a Gram-negative bacterium

Oral strains of Leptotrichia buccalis (Robin) Trevisan 1879, 138 (Basionym Leptothrix buccalis Robin 1853, 394) were found to be Gram-negative, on the basis of cell wall morphology and chemical composition. The G-C ratio 34 mole per cent places L. buccalis in a group with the genera Sphaerophorus and Fusobacterium in the family Bacteroidaceae.