legionella nagasakiensis legionella nagasakiensis legionella nagasakiensis is a gram-negative bacterium from the genus legionella which was isolated from a sample of hot spring water in aomori in japan and from human lung tissue. it is catalase-positive and rod-shaped, with a single polar flagellum. legionella nagasakiensis scientific classification domain: bacteria phylum: pseudomonadota class: gammaproteobacteria order: legionellales family: legionellaceae genus: legionella species: l. nagasakiensis binomial name legionella nagasakiensisyang et al. 2012 type strain atcc baa-1557, cdc-1796-jap-e, jcm 15315