haemophilus haemolyticus haemophilus haemolyticus haemophilus haemolyticus is a species of gram-negative bacteria that is related to haemophilus influenzae. h. haemolyticus is generally nonpathogenic, however there have been two cases of h.haemolyticus causing endocarditis. haemophilus haemolyticus scientific classification domain: bacteria phylum: pseudomonadota class: gammaproteobacteria order: pasteurellales family: pasteurellaceae genus: haemophilus species: h. haemolyticus binomial name haemophilus haemolyticus1923 (approved lists 1980) there is active research on h. haemolyticus especially in taxonomy and in identification, e.g.