youngiibacter fragilis youngiibacter fragilis youngiibacter fragilis is a gram-negative, non-spore-forming, rod-shaped and non-motile bacterium from the genus of youngiibacter. youngiibacter fragilis scientific classification domain: bacteria phylum: bacillota class: clostridia family: clostridiaceae genus: youngiibacter species: y. fragilis binomial name youngiibacter fragilislawson et al. 2014 type strain 232.1 synonyms clostridium fragilis youngiibacter fragile