yersinia ruckeri yersinia ruckeri yersinia ruckeri is a species of gram-negative bacteria, known for causing enteric redmouth disease in some species of fish. strain 2396-61 (= atcc 29473) is its type strain. yersinia ruckeri scientific classification domain: bacteria phylum: pseudomonadota class: gammaproteobacteria order: enterobacterales family: yersiniaceae genus: yersinia species: y. ruckeri binomial name yersinia ruckeriewing et al. 1978 a draft genome for yersinia ruckeri has been published.