enterococcus solitarius enterococcus solitarius enterococcus solitarius is a species of enterococcus. enterococcus solitarius scientific classification domain: bacteria phylum: bacillota class: bacilli order: lactobacillales family: enterococcaceae genus: enterococcus species: e. solitarius binomial name enterococcus solitariuscollins et al. 1989 transfer to tetragenococcus has been proposed.