ornithinibacillus contaminans ornithinibacillus contaminans ornithinibacillus contaminans is a gram-positive and spore-forming bacterium from the genus of ornithinibacillus which has been isolated from human blood from göteborg in sweden. ornithinibacillus contaminans scientific classification domain: bacteria phylum: bacillota class: bacilli order: bacillales family: bacillaceae genus: ornithinibacillus species: o. contaminans binomial name ornithinibacillus contaminanskämpfer et al. 2010 type strain ccug 53201, dsm 22953