legionella maceachernii legionella maceachernii legionella maceachernii is a gram-negative bacterium from the genus legionella which was isolated from a potable water cistern. l. maceachernii can cause pneumonia. legionella maceachernii scientific classification domain: bacteria phylum: pseudomonadota class: gammaproteobacteria order: legionellales family: legionellaceae genus: legionella species: l. maceachernii binomial name legionella maceacherniibrenner et al. 1985 type strain atcc 35300, ccug 31116, cdc px-1-g2-e2, cip 103846, dsm 16642, gifu 10745, gorman px-1-g2-e2, jcm 7566, nctc 11982, px-1-g2-e2 synonyms tatlockia maceachernii