Listeria innocua is a species of Gram-positive, rod-shaped bacteria. It is motile, facultatively anaerobic, and non-spore-forming. L. innocua was named innocua (innocuous) because, in contrast to Listeria monocytogenes, it does not readily cause disease in mammals.[1] Another Listeria species, L. seeligeri, was named after one of the discoverers of L. innocua.[2]
Biochemically, L. innocua is very similar to L. monocytogenes, except that L. innocua is usually non-hemolytic,[3][4]arylamidase-positive, and phosphoinositide phospholipase C-negative.[5] Although it is not generally considered a human pathogen, L. innocua was identified in 2003 as the cause of death of a 62-year-old, otherwise healthy, woman.[6]
As with other species in the genus, L. innocua occurs commonly in the environment (such as soil) and in food.[7] Strains of L. innocua have been shown to be able to form biofilms.[8]L. innocua has been tested and used as a laboratory surrogate for pathogenic L. monocytogenes in studies involving thermal, irradiation, and high-pressure processing of food.[9][10][11]
Knowledge of the structure of L. innocua was refined during the 2000s to help distinguish it from L. monocytogenes.[4]L. innocua may inhibit detection of L. monocytogenes if both species are present.[12] One study found that L. monocytogenes was detected in 5.4% of inoculated beef broth samples when L. innocua was also present.[13]
^Seeliger, H.P.R. (July 1981). "Apathogene listerien: L. innocua sp.n. (Seeliger et Schoofs, 1977)". Zentralblatt für Bakteriologie, Mikrobiologie und Hygiene. 1. Abt. Originale. A, Medizinische Mikrobiologie, Infektionskrankheiten und Parasitologie. 249 (4): 487–493. doi:10.1016/S0174-3031(81)80108-4.
^Jocelyne Rocourt and Patrick A. D. Grimont. Listeria welshimeri sp. nov. and Listeria seeligeri sp. nov. International Journal of Systematic Bacteriology, Oct. 1983, p. 866-869,
Vol. 33. No. 4. doi:10.1099/00207713-33-4-866"Listeria seeligeri (see.li.ger'i. M. L. gen. n. seeligeri of Seeliger, honoring Heinz P. R. Seeliger, German bacteriologist)"
^Char, Cielo D.; Guerrero, Sandra N.; Alzamora, Stella M. (5 November 2008). "Mild Thermal Process Combined with Vanillin Plus Citral to Help Shorten the Inactivation Time for Listeria innocua in Orange Juice". Food and Bioprocess Technology. 3 (5): 752–761. doi:10.1007/s11947-008-0155-x. hdl:11336/68077. S2CID84796275.
^RODRIGUEZ, O; CASTELLPEREZ, M; EKPANYASKUN, N; MOREIRA, R; CASTILLO, A (15 July 2006). "Surrogates for validation of electron beam irradiation of foods". International Journal of Food Microbiology. 110 (2): 117–122. doi:10.1016/j.ijfoodmicro.2006.01.041. PMID16690150.
^Pathanibul, Panchalee; Taylor, T. Matthew; Davidson, P. Michael; Harte, Federico (February 2009). "Inactivation of Escherichia coli and Listeria innocua in apple and carrot juices using high pressure homogenization and nisin". International Journal of Food Microbiology. 129 (3): 316–320. doi:10.1016/j.ijfoodmicro.2008.12.020. PMID19167772.