gram-negative coccobacilli.

Y. pestis is the agent of black death.
Y. pseudotuberculosis is an agent of mesenteric adenitis and septicaemia.
Y. enterocolitica, the most prevalent in humans, causes gastrointestinal syndromes, ranging from acute enteritis to mesenteric lymphadenitis.

Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales; Yersiniaceae; Yersinia