shigella boydii shigella boydii shigella boydii is a gram-negative bacterium of the genus shigella. like other members of the genus, s. boydii is a nonmotile, nonsporeforming, rod-shaped bacterium which can cause dysentery in humans through fecal-oral contamination. shigella boydii shigella boydii on hektoen enteric agar scientific classification domain: bacteria phylum: pseudomonadota class: gammaproteobacteria order: enterobacterales family: enterobacteriaceae genus: shigella species: s. boydii binomial name shigella boydiiewing 1949 shigella boydii is the most genetically divergent species of the genus shigella. there are 19 known serotypes of shigella boydii. s. boydii is restricted to the indian subcontinent. the species is named after the british bacteriologist john boyd. sequenced genomes shigella boydii strain bs512 (serotype 18; group 1) has one chromosome and five plasmids.