erwinia pyrifoliae erwinia pyrifoliae erwinia pyrifoliae is a gram-negative bacterium and a phytopathogen of asian pear trees (pyrus pyrifolia), causing necrotic disease. its type strain is ep16/96t(=cfbp 4172t =dsm 12163t. erwinia pyrifoliae scientific classification domain: bacteria phylum: pseudomonadota class: gammaproteobacteria order: enterobacterales family: erwiniaceae genus: erwinia species: e. pyrifoliae binomial name erwinia pyrifoliaekim et al. 1999