This microbe is a small, coccoid-shaped Gram-negative rod. Like most Yersinia species, it is more active metabolically and motile at 25-30 C than at 35-37 C. Little gas is produced from glucose. It is nonmotile at 35-37 C and little gas is produced from glucose. It has been isolated from sheep and other animals, soil, water, vegetables, and humans. Clinical isolates came from stool specimens, blood, and urine.