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: 20 to 30% of foodborne listeriosis infections in high-risk individuals may be fatal. In the European Union, listeriosis follows an upward trend that began in 2008, causing 2,161 confirmed cases and 210 reported deaths in 2014, 16% more than in 2013. Listeriosis mortality rates are also higher in the EU than for 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. Until 1992, 10 species were known, each containing two subspecies. By 2020, 21 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. The major human pathogen in the genus Listeria is L. monocytogenes. It is usually the causative agent of the relatively rare bacterial disease listeriosis, an infection caused by eating food contaminated with the bacteria. Listeriosis can cause serious illness in pregnant women, newborns, adults with weakened immune systems and the elderly, and may cause gastroenteritis in others who have been severely infected.
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.
Burkholderia is a genus of Pseudomonadota whose pathogenic members include the Burkholderia cepacia complex, which attacks humans and Burkholderia mallei, responsible for glanders, a disease that occurs mostly in horses and related animals; Burkholderia pseudomallei, causative agent of melioidosis; and Burkholderia cepacia, an important pathogen of pulmonary infections in people with cystic fibrosis (CF). Burkholderia species is also found in marine environments. S.I. Paul et al. (2021) isolated and characterized Burkholderia cepacia from marine sponges of the Saint Martin's Island of the Bay of Bengal, Bangladesh.
Weissella thailandensis is a species of Gram-positive bacteria. It is a homofermentative, sphere-shaped lactic acid bacteria. Its type strain is FS61-1T. Its genome has been sequenced.
Listeria marthii is a species of bacteria. It is a Gram-positive, motile, facultatively anaerobic, non-spore-forming bacillus. It is non-pathogenic, and non-hemolytic. The species was first isolated from Finger Lakes National Forest in New York. It is named after Elmer H. Marth, a researcher of L. monocytogenes, and was first published in 2010. L. marthii was the first new species of Listeria proposed since 1985.
Listeria rocourtiae is a species of bacteria. It is a Gram-positive, facultatively anaerobic, motile, non-spore-forming bacillus. It is non-pathongenic and non-hemolytic. The species was first isolated from pre-cut lettuce in Salzburg, Austria in 2002. It is named in honor of Jocelyne Rocourt, "whose work had a major impact on the taxonomy of the genus Listeria."
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.
Listeria grayi is a species of bacteria. It is a Gram-positive, facultatively anaerobic, motile, non-spore-forming bacillus. It is non-hemolytic. The species was first proposed in 1966. It is named after M.L. Gray, an early researcher in L. monocytogenes There are two subspecies of L. grayi: L. gray subs. grayi, and L. grayi subsp. murrayi.
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.
