Listeria monocytogenes is the species of pathogenic bacteria that causes the infection listeriosis. It is a facultative anaerobic bacterium, capable of surviving in the presence or absence of oxygen. It can grow and reproduce inside the host's cells and is one of the most virulent foodborne pathogens. Twenty to thirty percent of foodborne listeriosis infections in high-risk individuals may be fatal. In the European Union, listeriosis continues an upward trend that began in 2008, causing 2,161 confirmed cases and 210 reported deaths in 2014, 16% more than in 2013. In the EU, listeriosis mortality rates also are higher than those of other foodborne pathogens. Responsible for an estimated 1,600 illnesses and 260 deaths in the United States annually, listeriosis ranks third in total number of deaths among foodborne bacterial pathogens, with fatality rates exceeding even Salmonella spp. and Clostridium botulinum.
Listeria is a genus of bacteria that acts as an intracellular parasite in mammals. By 2024, 28 species had been identified. The genus is named in honour of the British pioneer of sterile surgery Joseph Lister. Listeria species are Gram-positive, rod-shaped, and facultatively anaerobic, and do not produce endospores.
Listeriosis is a bacterial infection most commonly caused by Listeria monocytogenes, although L. ivanovii and L. grayi have been reported in certain cases. Listeriosis can cause severe illness, including severe sepsis, meningitis, or encephalitis, sometimes resulting in lifelong harm and even death. Those at risk of severe illness are the elderly, fetuses, newborns and those who are immunocompromised. In pregnant women it may cause stillbirth or spontaneous abortion, and preterm birth is common. Listeriosis may cause mild, self-limiting gastroenteritis and fever in anyone.
The 2011 United States listeriosis outbreak was a widespread outbreak of Listeria monocytogenes food poisoning across 28 US states that resulted from contaminated cantaloupes linked to Jensen Farms of Holly, Colorado. As of the final report on August 27, 2012, there were 33 deaths and 147 total confirmed cases since the beginning of the first recorded case on July 31, 2011. It was the worst foodborne illness outbreak in the United States, measured by the number of deaths, since the Centers for Disease Control and Prevention began tracking outbreaks in the 1970s, or tied with the worst, an outbreak of listeria from cheese in 1985, depending on which CDC report is used.
Listeria ivanovii is a species of bacteria in the genus Listeria. The listeria are rod-shaped bacteria, do not produce spores, and become positively stained when subjected to Gram staining. Of the six bacteria species within the genus, L. ivanovii is one of the two pathogenic species. In 1955 Bulgaria, the first known isolation of this species was found from sheep. It behaves like L. monocytogenes, but is found almost exclusively in ruminants. The species is named in honor of Bulgarian microbiologist Ivan Ivanov. This species is facultatively anaerobic, which makes it possible for it to go through fermentation when there is oxygen depletion.
Listeria aquatica is a Gram-positive, facultatively anaerobic, nonmotile, non-spore-forming rod-shaped species of bacteria. It is not pathogenic. It was discovered from running water in Florida, and was first described in 2014. Its name comes from Latin, "found in water, aquatic".
Listeria riparia is a species of bacteria. It is a Gram-positive, facultatively anaerobic, non-motile, non-spore-forming bacillus. It is non-pathongenic. Its name refers to the riparian zone, and its discovery was first published in 2014.
Listeria cornellensis is a species of bacteria. It is a Gram-positive, facultatively anaerobic, non-motile, non-spore-forming bacillus. It is non-pathogenic. The species was named after Cornell University, and its discovery was first published in 2014.
Listeria floridensis is a species of bacteria. It is a Gram-positive, facultatively anaerobic, non-motile, non-spore-forming bacillus. It is non-pathongenic and non-hemolytic. The species was discovered in and named after Florida, and its discovery was first published in 2014.
Listeria grandensis is a species of bacteria. It is a Gram-positive, facultatively anaerobic, non-motile, non-spore-forming bacillus. It is non-pathongenic and non-hemolytic. The species was discovered in and named after Grand County, Colorado, and its discovery was first published in 2014.
Listeria newyorkensis is a species of bacteria. It is a Gram-positive, facultatively anaerobic, non-motile, non-spore-forming bacillus. It is non-pathogenic and non-hemolytic. It was discovered in a seafood processing plant in New York, and was first published in 2015.
Listeria weihenstephanensis is a species of bacteria. It is a Gram-positive, facultatively anaerobic, non-motile, non-spore-forming bacillus. It is non-pathongenic and non-hemolytic. It was discovered in a Lemna trisulca plant in a pond in Bavaria, Germany. The species name reflects the region in which it was first isolated, and was first published in 2013.
Listeria fleischmannii is a species of bacteria. It is a Gram-positive, facultatively anaerobic, non-motile, non-spore-forming bacillus. It is non-pathogenic and non-hemolytic. The species was first isolated in 2006 in Switzerland from hard cheese. The species is named after Wilhelm Fleischmann, a pioneer in the research of dairy products.
Listeria welshimeri is a species of bacteria. It is a Gram-positive, facultatively anaerobic, motile, non-spore-forming bacillus. It is non-pathogenic and non-hemolytic. It was isolated from decayed vegetation in the United States by H. J. Welshimer, after whom the species is named. The species was first proposed in 1983.
Listeria seeligeri is a Gram-positive, facultatively anaerobic, motile, nonspore-forming, bacillus-shaped species of bacteria. It is not pathogenic. The species was first isolated from plants, soil, and animal feces in Europe, was first proposed in 1983, and is named after Heinz P. R. Seeliger. Seeliger first proposed the species L. ivanovii and L. innocua, and published extensively on members of the genus Listeria.
Kathryn J Boor is an American food scientist and academic administrator. She is the dean of Cornell University Graduate School and vice provost for graduate education. Previously she served as the Ronald P Lynch Dean of the Cornell University College of Agriculture and Life Sciences.
Listeria costaricensis is a species of bacterium of the genus Listeria. It is a Gram-stain-positive, rod-shaped bacterium, non-spore-forming and facultatively anaerobic. Colonies are opaque, yellow-pigmented, with a flat shape and entire margin on BHI. Growth occurs at 22–42 °C, with optimal growth at 30–37 °C. It has motility at 37 °C. The bacteria is negative for catalase, haemolysis and nitrite reduction. It can be differentiated from other species of the genus Listeria by the absence of catalase reaction, production of acid from potassium 5-ketogluconate and production of a yellow pigment on BHI. It is presumably non-pathongenic due to the lack of haemolysis and pathogenicity genes on its genome.
'Listeria goaensis' is a new species identified under the genus Listeria. The type strain of the species was isolated from the sediment of estuarine mangrove swamp of the Mandovi river, Goa, India. The species shows weak hemolysis on 5% sheep and horse-blood agar plates.
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. Another Listeria species, L. seeligeri, was named after one of the discoverers of L. innocua.
