staphylococcus equorum staphylococcus equorum staphylococcus equorum is a gram-positive, coagulase-negative member of the bacterial genus staphylococcus consisting of clustered cocci. originally isolated from the skin of healthy horses, this species contains a cell wall similar to that of staphylococcus xylosus. staphylococcus equorum scientific classification domain: bacteria phylum: bacillota class: bacilli order: bacillales family: staphylococcaceae genus: staphylococcus species: s. equorum binomial name staphylococcus equorumschliefer et al. 1984 strains of s. equorum have been isolated from sausage and strains comprising subspecies of this species have been isolated from swiss mountain cheeses.