It is a Gram-positive, facultatively anaerobic, motile, non-spore-forming bacillus.

[3] Listeria murrayi (named after a co-founder of L. monocytogenes) was originally a separate species of Listeria when proposed in 1971.

[4] However, there was controversy over whether L. grayi and L. murrayi were the same species, or belonged in genus Listeria altogether.

In 1974, researchers suggested that a new genus be created for the two species, called, Murraya,[5] although furthers studies by other researchers in 1987 proposed that the two species remain in Listeria.

[6] In 1996, further studies showed that L. murrayi was a subspecies of L.