Heterogeneity within Fusobacterium nucleatum, proposal of four subspecies

Fusobacterium nucleatum strains, isolated from man and animals, were shown to comprise four centres of variation within the species by using a variety of biochemical tests. DNA-DNA hybridization data indicated that they should differences between the groups to warrant their placement into four subspecies for which we propose the following: F. nucleatum subsp. nucleatum (commonly isolated from diseased sites), F. nucleatum subsp. polymorphum (from healthy sites, most frequently isolated), F. nucleatum subsp. fusiforme (from healthy sites, most frequently isolated), F. nucleatum subsp. fusiforme (from healthy sites, rarely isolated) and F. nucleatum subsp. animalis from the colon of animals.