yersinia vastinensis yersinia vastinensis yersinia vastinensis is a gram-negative species of bacteria that has been isolated from human stools. all reported strains were isolated in france. yersinia vastinensis scientific classification domain: bacteria phylum: pseudomonadota class: gammaproteobacteria order: enterobacterales family: yersiniaceae genus: yersinia species: y. vastinensis binomial name yersinia vastinensisle guern et al. 2020